Fluke 8846A repair shenanigans. - Page 1
Forum section: electronics / repair

author: TiN
author_rank: Super Contributor
timestamp: August 20, 2018, 04:39:23 am
content: Yes, another repair thread about benchtop precision DMM. This time it's not so precise, as usual stuff I mangle with, but more typical and commonly used Fluke 8846 6.5-digiter.This is possible, thanks to John for his donation in the name of science (and making another article).I almost feel like it's Fluke invasion in the lab recently. It went from zero Fluke DMMs (87V is not accounted for) to three in no time.Rear side already show some damage to us, by broken tab of the power entry block. No biggie, just 26$ part.However when I try to power on thing, it just locks up in booting logo and nothing happens.Let's see who's inside? Good old LM399H, Fluke resistor networks, ALTERA Cyclone 1 FPGA's and bunch of other goodness.Transformer is rusty special, that's for sure. Nothing obviously broken. According to date codes on chips, it's made early 2006.So I mangled with it for few hours, replaced all electrolytic caps (usual rule when doing any older than 10yr equipment repairs), applied freeze spray on Cyclone FPGAs and stuff around in testing for cold joints, and poof, thing suddenly came to life..Too easy repair, I thought! I turned it off, on, off, on, seem to be working fine.Okay, let's have it meet the Hulk (that's nickname for my zombie calibrator).Connected, turned on for 10 minute warmup, hooked cable, and...-3.8ppm on 10V, -3ppm on 1V, no worries.-6.6ppm on 100V, spot on at 1000V, woohoo.Resistance checks, +10.4 ppm on 10kohm 4W, -47 ppm on 10 ohm. Not too shabby.ACV and DCI also working okay.Almost spot on, lol, with zero warming up time. Too good to be true, right?LAN port however does not work, cannot connect to it either in static IP mode, or DHCP. DHCP does not get any IP address from network. Perhaps LAN Phy is killed?Whatever, connected GPIB, that worked. So I setup simple python script to datalog 10VDC and went to bed (it was 5:30 am already).And sure enough, 10 minutes after I closed my eyes, poor meter died.It hangs on same power on initializing screen.BTW, Firmware on it is really old 1.0x, does anybody have newer 2.xx firmwares for 8846A? Fluke removed it from website for no good reasonAny ideas what to pursue next?

author: coromonadalix
author_rank: Super Contributor
timestamp: August 20, 2018, 10:35:51 am
content: Ask Fluke first for any FW updates, and on a previous thread someone had some boot up issues, check eevblog threads (maybe you have seen it ?)Fluke must had a good reason to remove it loll to keep some curious eyes away loll or complicated updates procedures, i don't know, you loose nothing to ask.Retry a more region precise freez spray to replicate your findings, as you say it can be any "cold joint soldering" and maybe an Flir camera to check thermal problems ?

author: Zucca
author_rank: Unknown
timestamp: August 20, 2018, 02:17:48 pm
content: Quote from: TiN on August 20, 2018, 04:39:23 amYou don't know I searched few days ago in google the "Hulk calibrator" nothing, "Fluke Hulk" nothing... and I gave up.

author: Mario87
author_rank: Frequent Contributor
timestamp: August 23, 2018, 08:29:35 am
content: Quote from: TiN on August 20, 2018, 04:39:23 amSo just to clarify, you didn't reflow or rework the solder joints? Just used the freeze spray? If you just used the freeze spray to test for cold solder joints and it started working again, then suddenly stopped once left on for a while I would look at reworking the solder joints, as it sounds like the freeze spray was enough to make the joint contract and make contact, but when on for a while it expands and breaks the connection.

author: TiN
author_rank: Super Contributor
timestamp: August 24, 2018, 04:08:13 am
content: Correct, didn't reflow anything. I freezed FPGA (as my suspects for BGA ball contacts) - nothing happened. Then freezed one of the IR diodes, and it got to work those 30 minutes.I have opto's and FPGA already in upcoming digikey order.

author: dacman
author_rank: Frequent Contributor
timestamp: August 28, 2018, 01:38:48 am
content: I searched forFluke8846A-Firmware2.10.882.24.zip (which I think should also work for the 8845A)and got a hit athttps://doc.xdevs.com/doc/Fluke/8846A/fw/but I get a forbidden error.

author: lowimpedance
author_rank: Super Contributor
timestamp: August 28, 2018, 02:55:23 am
content: LOL........But on the "Forbidden" ...I also ran into this error when looking to see what keithley 177 schematic quality was, (linked to it in another thread recently).Couldn't see the xdevs one so I uploaded a decent copy to that 177 thread.

author: TiN
author_rank: Super Contributor
timestamp: August 28, 2018, 03:09:58 am
content: There iseasier way?Repository tree migrated, so old URLs borked, sorry.I have parts from Digikey ordered for meter repair, will see if my intuition is right end of the week.IR shot reveals not much wrong

author: coromonadalix
author_rank: Super Contributor
timestamp: August 28, 2018, 10:21:18 am
content: What the part heating up at 78.43 degree, i find it very hot for an small part ?

author: glarsson
author_rank: Frequent Contributor
timestamp: August 28, 2018, 10:43:53 am
content: If I remember correctly it is the LM399.

author: TiN
author_rank: Super Contributor
timestamp: August 28, 2018, 10:52:37 am
content: Yep, that is ovenized LM399. It's internal constant temperature by design is about 95 °C.

author: analogRF
author_rank: Super Contributor
timestamp: August 31, 2018, 03:14:32 pm
content: I have a couple of questions about 8846A. I hope you dont find it irrelevant to this thread though-most serial numbers for this unit start with 9xx like 923 962 etc...but there is a unit I am negotiating for and the serial number starts with 118and I also have seen SN starting with 108. How do the firmwares match to these serial numbers?-can this Noritake display work in this DMMhttp://noritake-vfd.com/gu256x64d-7000bx.aspx-finally, does this meter has the measurement auto HOLD feature that holds the measurement and shows the last few of them like the newer Keysight models? I cannot see a hold key on the front panelEDIT: attached is the datsheet for that Noritake VFDsorry if this seems out of scope for this thread but since TiN is here and most other DMM experts will visit this thread I am hoping someone could help

author: coromonadalix
author_rank: Super Contributor
timestamp: August 31, 2018, 06:08:44 pm
content: Quote from: analogRF on August 31, 2018, 03:14:32 pmOhhhhhhhhhhhh nice display would be nice on a HP 34401 like the eevblog thread ...https://www.eevblog.com/forum/repair/hp-34401a-dmm-with-leaking-segments/

author: analogRF
author_rank: Super Contributor
timestamp: August 31, 2018, 06:12:32 pm
content: even mouser has it.although it does not have the BX suffix. I dont know what is the difference.however, my question remains: does this fit 8846A?https://www.mouser.ca/ProductDetail/Noritake/GU256X64D-7000?qs=sGAEpiMZZMvkC18yXH9iImO64zrkImZBrdAMGtROkPM%3d

author: Kleinstein
author_rank: Super Contributor
timestamp: August 31, 2018, 09:56:43 pm
content: The display is a graphics type display with driver board -so it at least the same class of display like in the 8846. So there is still a chance is might work, but I don't know.It would definitely not fit the 34401 or the Keithley 200x meters, as these use 7 seg based displays.

author: Vgkid
author_rank: Super Contributor
timestamp: August 31, 2018, 10:28:36 pm
content: @TiNWhere did your manual repository go . I really liked it.

author: TiN
author_rank: Super Contributor
timestamp: September 01, 2018, 04:34:47 am
content: Its all there, just update links due server config changes.

author: analogRF
author_rank: Super Contributor
timestamp: September 05, 2018, 12:36:38 pm
content: I was still hoping someone could answer my earlier question:does this meter (8846A) has the auto HOLD feature that holds the measurement and shows the last few of them like the newer Keysight models? I cannot see a hold key on the front panel

author: Samogon
author_rank: Frequent Contributor
timestamp: September 05, 2018, 04:27:34 pm
content: Quote from: analogRF on September 05, 2018, 12:36:38 pmAs i understand they implemented "Histogram Function" which is more advanced, but not really hold function as we used to.

author: dacman
author_rank: Frequent Contributor
timestamp: September 05, 2018, 09:34:55 pm
content: It has a Memory key (next to F5). If memory is turned on, the meter can store several thousand readings internally or optionally externally if it is an 8846A. (The 8846A has a USB port that can be used to store readings.) If you wanted to see the last few readings, it has a Last softkey that could be used then you could scroll backward. It also has an Analyze key (which is separate from the Memory function) that can be used to turn on STATS. Then things like average and standard deviation and high/low can be displayed and it can show a graph of the readings. Histogram is a graph of the standard deviations.

author: analogRF
author_rank: Super Contributor
timestamp: September 05, 2018, 10:05:32 pm
content: Quote from: dacman on September 05, 2018, 09:34:55 pmyes, I know but that would also store all the readings between probings. With reading hold (or probe hold as keysight call it) it stopscapturing when you take your probe away and reads a new measurement when you touch the probe and only if the new valueis different than the last one by more than 1%. With simple memory it keeps reading and storing the noise when you are not probing.I have looked all over the manuals and I am 100% convinced now that neither 8846A nor DMM6500 have this simple useful feature.All keysight multimeters and most older Fluke have it and even rigol and siglent have this. It's a simple software thing and i dont know why they decided to do away with it

author: Johnny10
author_rank: Frequent Contributor
timestamp: September 24, 2018, 04:29:42 pm
content: Just curious what it took to fix unit ? If you needed FPGA.

author: TiN
author_rank: Super Contributor
timestamp: September 24, 2018, 05:20:41 pm
content: It's still dead.

author: Johnny10
author_rank: Frequent Contributor
timestamp: September 24, 2018, 05:44:02 pm
content: BummerJust asking cause I had chance to buy a couple of non-functioning units or a couple of functioning units.After your answer I decided on functioning units.I have to correct that... I bought a couple of units with errors which keep unit from functioning!

author: Jwalling
author_rank: Unknown
timestamp: October 06, 2018, 05:26:05 pm
content: Hmm...Seems like this could be a common problem.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 06, 2018, 06:40:45 pm
content: What does it cost to send them to Fluke for service?Or is that a question not allowed in the repair forum. :-)

author: GreyWoolfe
author_rank: Unknown
timestamp: October 06, 2018, 08:15:34 pm
content: Quote from: Johnny10 on October 06, 2018, 06:40:45 pmAt least you didn't ask that question in the TEA thread!!

author: DC1MC
author_rank: Super Contributor
timestamp: October 06, 2018, 08:20:39 pm
content: Quote from: Johnny10 on October 06, 2018, 06:40:45 pmThe cost of sending them to Fluke for service is acceptable, on the other side, the cost of the servicing, this is what kills you.

author: Jwalling
author_rank: Unknown
timestamp: October 06, 2018, 08:43:01 pm
content: Quote from: DC1MC on October 06, 2018, 08:20:39 pmYep. IME, it costs about as much, if not more, than a used one in good working order. The four I have appear to have the same fault, but one is a bit different in it's behavior... More tomorrow.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 06, 2018, 08:47:07 pm
content: Yea, why did I even askI should know better! Waaaaayyyyy too expensive.I have two units with same error but one has all power rails working properly and one has shorted -15 and +15.So same error covers a lot of different issues.

author: giosif
author_rank: Frequent Contributor
timestamp: October 06, 2018, 09:01:17 pm
content: Anyone getting bored of one of these sick puppies, I'd be glad to alleviate the burden.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 07, 2018, 03:01:10 am
content: Sad to see theses meters having problems and Fluke does'nt acknowledge a thing

author: TiN
author_rank: Super Contributor
timestamp: October 07, 2018, 03:33:01 am
content: What would you want Fluke to do?I'm sure they will help you with repair for 90% of new unit costSo far my experience with this 8846 just tend to consider it as overcomplicated design filled with unfriendly firmwares. BGA FPGAs with NIOS SoPC, no way to backup firmware, Fluke withdrawal of their own published FW and poor service documentation. Sure I'd accept that in meter like 8508A, but not in benchtop unit like 884X.

author: Jwalling
author_rank: Unknown
timestamp: October 07, 2018, 12:18:49 pm
content: Quote from: Johnny10 on October 06, 2018, 08:47:07 pmYou're probably right. I can see the self test routine:1 to 199: Run a whole bunch of self tests.200: If anything fails, sit there and look stupid.So the four units I have were bought by a friend of mine who brings me lots of repair work from a Govt. auction. Normally, he doesn't buy test gear, but other industrial equipment (hardness testers, etc)https://www.govdeals.com/index.cfm?fa=Main.Item&itemid=17539&acctid=2863If he had asked me about them before buying, I would have told him to stay away!Symptoms:1. All hang at the init screen.2. When there is a USB thumb drive plugged in, three of them access the drive at 2 seconds and 8 seconds after powering on. No further accesses are done after that. The fourth one accesses the drive at 2 seconds, then at 3 second intervals over and over forever.3. All voltage rails are verified and correct.4. None respond to a GPIB scanning5.All connect to LAN, and activity pulses can be seen at two second intervals. One time I saw one of them connect to my Asus router and get an IP address. I was unable to get it to repeat this though...6. I never see any data going across the opto-coupler transmitter at DS3. The other one is transmitting a steady stream of pulses. I'll have to check whether the receiver is getting them, but you got to pull the board or remove the cover to access it. @ TiN: Does this sound like yours?EDIT: The data stream from DS2 is making it across fine. Whether the data is correct, though...

author: Jwalling
author_rank: Unknown
timestamp: October 07, 2018, 12:43:55 pm
content: Quote from: Johnny10 on October 06, 2018, 08:47:07 pmShorted to GND? Do you have a 4 wire DMM?

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 07, 2018, 01:54:32 pm
content: The 15 V rail sits at 2.18V the -15 at 0.434VFound a comparator, IC LM393, that is running over 200 degrees F, on the second unit only 87degrees.Will be investigating that today.

author: Shock
author_rank: Super Contributor
timestamp: October 07, 2018, 03:03:26 pm
content: Tin these look under done, please bake yours more.Might be something to look at I cannot see from the thermal image what temp the right hand one is at. Did you check them and are those tantalums between?Did you freeze spray that area at all? You may have hit a cap.

author: Jwalling
author_rank: Unknown
timestamp: October 07, 2018, 03:41:44 pm
content: Quote from: Shock on October 07, 2018, 03:03:26 pmA better pic you can zoom in on:https://xdevs.com/doc/Fluke/8846A/img/fixed_in.jpg

author: HighVoltage
author_rank: Super Contributor
timestamp: October 07, 2018, 04:37:47 pm
content: I used to have a 8846A because it was so much praised here on eevblog.My unit was bought used with a very weak VFD, but I thought that would be an easy fix.I tried forever to get a new VFD from Tektronix or other sources and I finally gave up and let go of the instrument.

author: TiN
author_rank: Super Contributor
timestamp: October 07, 2018, 11:48:52 pm
content: All power on my 8846 is fine, nothing cooking or shorted. It is not relevant to the "init screen hang" issue, because meter should boot even with inguard section completely unpowered (removed transformer cable from inguard).Jwalling, yes, there is no life on optos from outguard to inguard. There is slow square wave on pair from inguard to outguard (perhaps just heartbeat signal).I have tried so far things like:* Replace RJ45 magnetics and Eth phy (suspected dead LAN input, that get NIOS CPU in FPGA stuck waiting) = no help.* Replaced outguard SDRAM = no help* Replaced outguard FPGA (bought new Cyclone from Digikey) = no help* Freezespray bunch of stuff around = no help anymore. Originally it helped and made meter work randomly for shortime.When it was working, it took about 10-20 seconds to boot from init screen, and you can hear relay click after 2-3 sec from power on. Now it however does not click anything, just sitting silly.Supervisor chip that drive reset to NIOS FPGA is ok, reset is correctly toggled high on power on. There is some life to SDRAM data pins, so it's doing something.I tried to probe RS232 chip in hope to find debug CPU console output, but there was no signals.So far best shot would be to trace JTAG to the debug connector, and connect USB Blaster, to try if anything can be done from that side (perhaps read back NOR flash).But it's a long shot, as we don't have binary image from the FW flash. 8846A update tool have only bits and pieces, but not the full dump binary.

author: Jwalling
author_rank: Unknown
timestamp: October 08, 2018, 10:40:15 am
content: Quote from: TiN on October 07, 2018, 03:33:01 amRe: Firmware for the Fluke version, have you tried contacting Erik?https://www.eevblog.com/forum/testgear/fluke-8846a-anyone-that-got-the-updated-firmware-downloaded/msg1511872/#msg1511872https://www.eevblog.com/forum/testgear/fluke-8846a-anyone-that-got-the-updated-firmware-downloaded/msg395578/#msg395578Apparently, Fluke removed the update utility as too many people could not follow the instructions. Maybe they were bricking them?assets.fluke.com/software/bench/readme.pdf

author: Circlotron
author_rank: Super Contributor
timestamp: October 08, 2018, 10:46:41 am
content: Quote from: Johnny10 on October 06, 2018, 06:40:45 pmYou could always couch it in terms of how much money you would be saving ;-)

author: TiN
author_rank: Super Contributor
timestamp: October 08, 2018, 11:21:38 am
content: JwallingYou think where I gotthis one from?

author: Jwalling
author_rank: Unknown
timestamp: October 08, 2018, 11:39:24 am
content: Quote from: TiN on October 08, 2018, 11:21:38 amOh. sorry. I thought you were looking for firmware...

author: Jwalling
author_rank: Unknown
timestamp: October 08, 2018, 11:51:36 am
content: Doing some more poking around.Cost to repair from Tek is $895.The three units I have that behave the same with a USB drive attached, were from the University of Central Florida. All three had an RMA generated, but they never sent them in. Probably when they found out the repair cost.The fourth belonged to Entest Inc.My gut feeling is that the firmware is probably corrupted on these. But it's just a guess...Oh for the days when firmware was in PLCC sockets.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 08, 2018, 01:06:19 pm
content: $895.00 Guess that answers my question !About the price of a used 8846A DMM.But it comes back calibrated also!

author: coromonadalix
author_rank: Super Contributor
timestamp: October 08, 2018, 03:24:23 pm
content: 895$ Each dmm or the loot ??

author: Kleinstein
author_rank: Super Contributor
timestamp: October 08, 2018, 04:16:23 pm
content: I think from the screen shots it should be clear that this is $895 per unit and excluding shipping and likely sales tax. Given the rather high price some units might end up as display donors. The repair price is so high, because is in many cases this would be a board swap.Firmware corruption could be possible, though I would expect a check sum test at the beginning and than a corresponding error message - just like TiN's 3458. Several units with a similar fault might make it worth to dig a little further. As a broken communication should be caught by the ground based part, I would suspect trouble with the outbound part. Just in case one could do a test with an intentionally broken link - at least this should be caught, as it would be an expected failure mode (e.g. spider at the optical link).

author: TiN
author_rank: Super Contributor
timestamp: October 08, 2018, 10:33:10 pm
content: KleinsteinUsual NIOS people not thinking the same way as Motorola designers of 3458 FW. Why need to include debug/fault info for user, if we can just demo pretty Fluke intro bitmap on that lovely VFD, and ask user to pay for service?Friend of mine tried to block opto on working 8846 and meter still was able to boot into main UI, just don't show any readings. So if meter no boot = outguard issues.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 08, 2018, 11:00:38 pm
content: Tin, you changed Outguard FPGA correct?

author: TiN
author_rank: Super Contributor
timestamp: October 08, 2018, 11:24:20 pm
content: Yes.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 08, 2018, 11:55:00 pm
content: On my unit the Inguard is not responding.I have a functioning Outguard.But no readings on display...Removing the shields from the phototransistors reveals "XC6115 series high-precision, low current consumption voltage detectors with watchdog. The series consist of a reference voltage source, delay circuit, comparator and output driver".Which is what triggers my error after a few seconds delay. I can see the pattern on the oscilloscope.Outguard waiting for a signal, then resetting after time delay, coinciding with the error message appearing on the display.

author: TiN
author_rank: Super Contributor
timestamp: October 09, 2018, 04:16:37 am
content: Johnny10, slow down, or you will get me wasting time on this 8846 again.On serious note - good find. I think reversing schematics for isolation interface would be rather easy.

author: picburner
author_rank: Frequent Contributor
timestamp: October 09, 2018, 06:51:31 am
content: QuoteTo me U54 & U63 look like AD8601ARTZ op-amp.In fact a phototransistor pin is connected to the -in input of the op-amp and this makes sense.What would it do to connect to the wd terminal of an XC6115??

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 09, 2018, 12:15:18 pm
content: I am certainly not an expert on SMD markings since I have been wrong before.SMD part marked AAA 5 pins SOT-25.I used SMD-Codes from 2007

author: picburner
author_rank: Frequent Contributor
timestamp: October 09, 2018, 01:23:35 pm
content: The smd codes are difficult to interpret and often generate confusion because the same code can correspond to many different devices.I don't have this DMM and then I can't make measurements but to amplify the signal of a phototransistor I would use a hi-speed op-amp not avoltage detector with watchdog

author: Miti
author_rank: Super Contributor
timestamp: October 17, 2018, 02:39:42 am
content: Hi Tin,My 8845A had a dying IR LED but it popped an error, I don't remember which error. I replaced it with a regular IR LED from an old TV remote and it works well for about 2 years now. Spray cold those LEDs, replace them. It's worth a try.

author: TiN
author_rank: Super Contributor
timestamp: October 17, 2018, 04:37:24 am
content: Quote from: Miti on October 17, 2018, 02:39:42 amIR led was second thing I swapped (first one was check and confirmed good, also recap all power supply circuits). Didn't help.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 20, 2018, 11:14:03 pm
content: OK, More testing validates picburnerPin 1 Signal OutPin 4 InputPin 5 V+ 3.43Von the AAA 5 pin IC AD8601ARTZ

author: massivephoton
author_rank: Contributor
timestamp: October 31, 2018, 02:03:04 pm
content: Quote from: TiN on August 20, 2018, 04:39:23 amToo bad ethernet didn't work even while the unit worked. Telnet on port 23 asks for login/psw, which is disclosed in plaintext in the available 2.x firmware files. Once inside, there's uCLinux basic commands, ftp server, some scripts for comm configuration as well as default settings stored.Quote from: Jwalling on October 07, 2018, 12:18:49 pmDid you ever manage to get an IP again? You could try to login on port 23 and inspect. Also, there are chances that the firmware update (or downgrade?) tool works from this point.My unit runs the latest firmware listed in Xdevs.com, and I'm having a minor issue that if I break the telnet connection sometimes it no longer accepts SCPI connections on port 3490, but keeps alive at port 23. I know I shoudn't be using wi-fi with instruments, but hey, it's pretty good when it works. Already tried to reboot each network devices in the path between the notebook and the DMM, but didn't work. I'd like to telnet connect on port 23 and restart the telnet process to regain SCPI control on port 3490, but when I kill the only telnetd process listed on `ps aux` command, the connection on port 23 is interrupted. I can reconnect on port 23, but it doesn't restore telnet connection on port 3490. Also, if I run a reboot command, it restarts the outguard processor, the DMM keeps measuring and updating the display, but still no connection on telnet on port 3490.I can try to replicate tests or copy files from the instrument if needed. You may try to convince me, but I just don't feel inclined to open the unit, since it's still under warranty. Sorry, I couldn't resist and turned it on instead of tearing it apart. :-(Hope your meters return from the dead soon!Happy halloween!

author: SilverSolder
author_rank: Super Contributor
timestamp: November 02, 2018, 02:03:18 am
content: Quote from: TiN on August 20, 2018, 04:39:23 amWhat is the purpose of the aluminum box over the input connections on the 8508A in the picture? In later pictures, it (or a clone) appears on the calibrator as well.

author: massivephoton
author_rank: Contributor
timestamp: November 06, 2018, 02:58:01 am
content: Had a little more time to play on the weekend.Quote from: TiN on October 07, 2018, 11:48:52 pmProbably, but I wouldn't be so sure on v1 firmware.QuoteThe measurement app is ca. 1MB in size, /usr/bin/zfp. Killing this process halts measurements, freezing the display. I'd expect the opto communication to halt too. Zfp app is called at the end of /etc/rc script:Code:#!/bin/sh## system startup.# expand and mount the ramdisk#/bin/dd if=/usr/bin/ramfs.img of=/dev/ram0/bin/expand /ramfs.img /dev/ram0/bin/mount -t ext2 /dev/ram0 /tmp -n/bin/expand /ramfs.img /dev/ram1/bin/mount -t ext2 /dev/ram1 /var -n# mount proc file system/bin/mount -t proc proc /proc -n# mount sysfs/bin/mount -t sysfs sysfs /sys -n# mount the jffs2 R/W file system# /bin/mount -t jffs2 /dev/mtdblock2 /usr -n# mount the romfs RO (SAFE) partition/bin/mount -t romfs /dev/mtdblock4 /safe -n# Configure the GPIB interface/usr/bin/gpib_config# manually assign ip address (uncomment and edit as appropriate)# note: first ifattach (no args) sets local loopback/bin/ifattach# Set the MAC and IP address/usr/bin/setmac/usr/bin/ipenet# start up the internet superserver/bin/inetd &# run 2 sec delay/usr/bin/me_sleep#If the application was installed using a windows#machine the files may not be executable so change#the permissions just-in-casechmod 777 /usr/bin/zfp#Start up the application/bin/sh -c /usr/bin/zfp &# that's it... successexit 0QuoteIt's also possible that eth0 initialization script didn't complete. The firmware update manual mentions the ip 169.254.115.202. Also, setenet script on /usr/bin further mentions the following ip/mac tables:Code:mac_address='00:80:40:00:20:AE'ip_address='129.196.136.131'case $1 inhalfdome) mac_address='00:80:40:00:20:A6' ; ip_address='129.196.136.112' ;;mlandich) mac_address='00:80:40:00:20:A7' ; ip_address='129.196.136.116' ;;dbartley) mac_address='00:80:40:00:20:A8' ; ip_address='129.196.136.117' ;;zippy) mac_address='00:80:40:00:20:A9' ; ip_address='129.196.136.119' ;;rdz) mac_address='00:80:40:00:20:AA' ; ip_address='129.196.136.122' ;;denny) mac_address='00:80:40:00:20:AB' ; ip_address='129.196.136.125' ;;jwitters) mac_address='00:80:40:00:20:AC' ; ip_address='129.196.136.129' ;;britz) mac_address='00:80:40:00:20:AD' ; ip_address='129.196.136.130' ;;test1) mac_address='00:80:40:00:20:AE' ; ip_address='129.196.136.131' ;;test2) mac_address='00:80:40:00:20:AF' ; ip_address='129.196.136.200' ;;esacNote how close the mac address found here:Quote from: Jwalling on October 07, 2018, 12:18:49 pmOn my unit the mac address starts with 00:C0:, which might suggest that something is wrong on eth0 initialization. I'd suggest to ping and/or telnet these ips using an auto mdi-x adapter or crossover cable configured with an ip on the same subnet.Some services to play with:Code:ftp-data20/tcpftp21/tcptelnet23/tcpuptime24/tcphttp80/tcpI think uptime can be useful to an automation task know that the unit is already warm-up. Telnet connection return an increasing number, not sure, but maybe tens of minutes, and immediately closes connection.QuoteAny chance that the flash memory got its last breath from a cold breeze?QuoteWhen zfp app is launched it adjusts measurements, and the relays fill their mag lungs to cry hello world!QuoteI didn't see any indicia of console on tty on the files. I didn't even connect using serial yet, but I'd try 115200 baud, at least on later firmwares, since inittab file on /etc shows:Code:# inittab for uClinux# Format:# ttyline:termcap-entry:getty-commandttyS0:vt100:/bin/agetty 115200 ttyS0# ttyS1:vt100:/bin/agetty 9600 ttyS1# ttyS2:vt100:/bin/agetty 9600 ttyS2# ttyJ0:vt100:/bin/agetty 115200 ttyJ0Hope there's something like uboot halt on any key here...QuoteI agree, but only if ethernet really not initialized, and also if we don't find any boot console at tty.QuoteI must say that the firmware seems to include the full firmware, in pieces, it's true, but integer pieces. After extracting recursively the firmware, we get a folder 'instruments_e6f0b851bdee_zg_ia_sf/884X/bin' holding the firmwares, with the following files: beta_noinfo_reversed.rbf,busybox, f884x_versions, flashcp, flash_eraseall, jffs2.bin, me_sleep, u69_nios.flash, vmlinux.bin, vmlinuxRev14ptf.bin, vmlinuxRev17ptf.bin, zfp, zfp_837;and the recipes under /884X/procedures show exactly where each image should go.One last bit, restarting zfp app restores my measurement telnet connection at port 3490.Regards.

author: TiN
author_rank: Super Contributor
timestamp: November 06, 2018, 03:07:14 am
content: Cudos for the investigations, that could be very helpful. Perhaps its possible to build "binary image" that can be flashed to new flash chip to try? My meter have 1.x few so there is no "source" update part for this version. But I'd love to try that and even buy programmer that can do TSSOP56 chips.

author: massivephoton
author_rank: Contributor
timestamp: November 06, 2018, 01:12:54 pm
content: Quote from: TiN on November 06, 2018, 03:07:14 amI think it's possible to build a binary. I'm not sure if mtdblock[0-4] really are partitions of the same flash chip. If so, we can find the offsets and create the image. Also, I can try to copy the entire 2.37 flash from my unit to a single file on a usb pendrive. Just don't know how to do it yet.Also, the firmware 2.10.882.24 already includes full images to upgrade from 1.x:Code:09/29/06-16:59,null [OG SW]10/06/06-22:22,null [IG SW]09/26/06-15:16,null [OG HW]09/26/06-15:23,null [IG HW]Sep 27 2006,null [OS Build]r1,proc_649_130 [Rel. 1 --> Rel. 7: upgrade using proc_649_130]04/02/07-08:10,null10/06/06-22:22,null09/26/06-15:16,null09/26/06-15:23,nullSep 27 2006,nullr2,proc_688_130 [Rel.2 --> Rel.7: upgrade using proc_649_130]11/09/07-09:21,null09/14/07-21:54,null08/20/07-20:19,null08/21/07-16:30,nullAug 23 2007,nullr3,proc_837_200_082307 [Rel.3 --> Rel.7: upgrade using proc_649_130]11/09/07-09:21,null09/14/07-21:54,null08/20/07-20:19,null08/21/07-16:30,nullOct 25 2007,nullr4,proc_837_200_102507 [Rel.4 --> Rel.7: upgrade using proc_649_130]11/09/07-09:21,null12/12/07-20:15,null08/20/07-20:19,null08/21/07-16:30,nullNov 30 2007,nullr5,proc_837_201 [Rel.5 --> Rel.7: upgrade using proc_649_130]11/09/07-09:21,null02/15/08-18:44,null08/20/07-20:19,null08/21/07-16:30,nullNov 30 2007,nullr6,proc_837_210 [Rel.6 --> Rel.7: upgrade using proc_649_130]02/14/08-08:54,null02/15/08-18:44,null08/20/07-20:19,null08/21/07-16:30,nullNov 30 2007,nullr7,proc_882_210 [Rel.7 --> Rel.7: upgrade using proc_649_130]For instance, the code for procedure proc_649_130 is:Code:connect,nullwiz,syst:remstep,1tcomm,rm /usr/bin/vmlinux.bintcomm,rm /usr/bin/u69_nios.flashtcomm,rm /usr/bin/vmlinuxRev14ptf.bintcomm,rm /usr/bin/beta_noinfo_reversed.rbftcomm,rm /bin/busyboxfcwd,/usr/fget,calparamsfcwd,/bin/fput,busyboxfcwd,/usr/bin/fput,vmlinuxRev14ptf.binfput,flashcpfput,flash_eraseallfput,zfpfput,me_sleeptcomm,chmod 777 /usr/bin/flashcptcomm,chmod 777 /usr/bin/flash_erasealltcomm,chmod 777 /usr/bin/me_sleeptcomm,rm /usr/bin/config/*tcomm,mv /usr/bin/vmlinuxRev14ptf.bin /usr/bin/vmlinux.bintcomm,/usr/bin/flashcp -v /usr/bin/vmlinux.bin /dev/mtd1tcomm,rm /usr/bin/vmlinux.bindisconnect,nullreboot_simple,nullconnect,nullwiz,syst:remstep,2fcwd,/usr/bin/fput,vmlinux.bintcomm,/usr/bin/flashcp -v /usr/bin/vmlinux.bin /dev/mtd2tcomm,rm /usr/bin/vmlinux.binfput,beta_noinfo_reversed.rbftcomm,/usr/bin/flashcp -v /usr/bin/beta_noinfo_reversed.rbf /dev/mtd0disconnect,nullreboot_simple,nullconnect,nullwiz,syst:remstep,3tcomm,/usr/bin/flash_eraseall -j /dev/mtd3tcomm,mkdir /mnt/jffs2_blk3tcomm,chmod 777 /mnt/jffs2_blk3tcomm,/bin/mount -t jffs2 /dev/mtdblock3 /mnt/jffs2_blk3 -ntcomm,rm -Rf /mnt/jffs2_blk3/*tcomm,dd if=/dev/mtd1 of=/mnt/jffs2_blk3/jffs2.bintcomm,flashcp -v /mnt/jffs2_blk3/jffs2.bin /dev/mtd1disconnect,nullreboot_simple,nullconnect,nullwiz,syst:remstep,4fcwd,/usr/bin/fput,u69_nios.flashrestorecal,nullwiz,syst:remstep,5wiz,ig_download "/usr/bin/u69_nios.flash"message,"UPDATE DONE"disconnect,nullend,endProcedure proc_882_210 does nothing, since the installed firmware is already release 7.

author: Nifty
author_rank: Contributor
timestamp: April 22, 2021, 06:16:35 pm
content: So many brave (or naive) people

author: Johnny10
author_rank: Frequent Contributor
timestamp: April 22, 2021, 06:40:09 pm
content: You can buy a working used one on ebay for 550 dollars. Oops, I take that back, all 12 are sold.Tektronix DMM4050 6.5 Digit MultimeterItem InformationCondition:UsedQuantity:0 available 12 sold / See feedbackPrice:US $550.00$47 for 12 months with PayPal Creditopens a installment calculator layer*

author: BU508A
author_rank: Super Contributor
timestamp: December 13, 2021, 07:50:43 pm
content: I've found the datasheets for the two display versions:Noritake Itron VFD Module, 256x64 Dot GraphicType 1: GU256x64D-7000Type 2: GU256x64D-7000BXDifferences I've found so far:- BX is newer (2016 vs. 2006)- block diagram- BX has a higher power consumption / higher current consumption- to be continued ...TME has five tpye 1 displays ready for delivery:https://www.tme.eu/de/details/gu256x64d-7000/vfd-displays/noritake-itron/

author: dew
author_rank: Contributor
timestamp: March 04, 2022, 04:44:40 am
content: I'm new to this, but AFAIK:Fluke is using it's own controller for VFD display in 884XA meters. VFD part is MN25664J. It is an older model with 5V supply and logic.Same VFDs are used in GU256X64D-3900 or GU256X64D-3900B displaysNoritake (manufacturer?)MouserDigiKey (3900),DigiKey (3900B)These GU[...] displays come mounted on their own controller with UART interface that you would not need for the Fluke. Very hard to take VFD off the controller. Glued with double side tape across the whole surface.GU256X64D-7000_tme and GU256X64D-7000BX_tme both seem to use MN25664M VFD module (glass part). M version is newer, uses 3.3V and a different interface.

author: ASEMechanic
author_rank: Newbie
timestamp: January 21, 2023, 04:51:23 am
content: Quote from: dew on March 04, 2022, 04:44:40 amOkay, I'm going to revisit this very old thread because it actually helped me out this week. And this will be a long post, so grab your popcorn.I bought a Fluke 8846A off eBay fairly cheap because it had an aging display with pretty bad burn-in. Still perfectly functional and recently calibrated, so I thought I'd give it a shot. Unit arrived, plugged it in, and fired it up. As expected, the display was a bit dim and the burn-in was noticeable, but otherwise it was perfectly functional. Certainly not disappointed as I knew what I was getting.Aaaaaaand then I began the process of trying to locate a replacement display. Going through normal channels yielded zip. No Fluke replacement parts anywhere. Well, it's an older discontinued device so I get it. Started scouring forums and came across the XDevs thread regarding a Fluke 8846A teardown.https://xdevs.com/fix/f8846a/(This is, incidentally, the exact same article and unit found at the start of this very thread posted by TiN, although I hadn't seen this thread yet.) Anyway, it thankfully indicated the part number of the VFD and gave me something else to work with.2 days of scrounging, parts sourcing, and even looking for dead units to salvage a display from again yielded nothing. I was about to just give up and resign myself to a dim display, at least until I could procure a reasonable working one later on down the road, when I came across this very thread. The post above gave me hope, although I had to be realistic that it was from almost 5 years ago and that I may not be able to find anything available.Leave it to Mouser... They actually have 58 (now 57) of the GU256X64D-3900B displays in stock. Yes, they're pricey at $270.48, but they absolutely do have the MN25664J VFD display on them. The same display that is in the 884xA meters. I ordered one and hoped for the best. In the meantime, I went ahead and opened the unit up to remove the display and controller from the front panel. I wasn't going to touch it until I could verify that I could remove the new display from the controller, but at least it was just that much less to do when it arrived.Got my display in today (Friday) at about 11:00 AM. Verified that the pinout all looked correct and then went to work. First thing was to separate the adhesive. This was actually easier than I had anticipated. I'm not sure about the display Dew had observed, but this one had 2 thinner strips of double sided tape on the edges instead of one wide sheet. A little Goof-Off and a thin razor knife made quick work of separating the controller board from the VFD, leaving only the terminals. 21 terminals to be exact. Using a couple small pieces of PCB for leverage between the VFD and controller board, I applied a little pressure and used the hot air from my solder rework station to slowly draw the terminals out. This took about 5 minutes as I didn't want to force anything and possibly break a pin or crack the glass of the VFD.Once I got it all apart, I verified that the part number was identical (it was a match!), and then I then went to work on taking the old display off of the Fluke adapter board. This was considerably easier as I just cut the old one off and removed the terminal pieces one at a time. A little solder wick, a quick wash, and the board was ready to go. I inserted the new VFD into the adapter, spot soldered the end terminals, and then I placed the assembly into the meter panel so that I could get the offset correct with no gaps. With the adapter board screwed back in place, I finished soldering up the terminals. After a quick check to make sure everything looked good, I then reassembled the meter.Fired the unit up and it worked like a champ! Display is crisp and clear. I ran the display test and that completed perfectly. This whole process went about as well as could have been expected (or hoped) and only took about 2 hours from start to finish.If anyone is in need of a VFD for the Fluke 884xA, I can tell you that this is about the only option available. If you have a solder rework station and have no qualms about sacrificing the GU256X64 controller, then this is a sure way to get a new display. It works well and it isn't nearly as difficult to accomplish as it appears.Mouser still has these:https://www.mouser.com/ProductDetail/Noritake/GU256X64D-3900BNoritake also still lists these on their website:https://noritake-vfd.com/gu256x64d-3900b.aspxI hope this post helps someone the same way that the previous post helped me.Good luck!!The Noritake GU256X64D-3900B display disassembledThe Fluke 8846A display and adapter boardThe Fluke 8846A with new VFD installed

author: bdunham7
author_rank: Super Contributor
timestamp: January 21, 2023, 05:03:40 am
content: Quote from: ASEMechanic on January 21, 2023, 04:51:23 amGood work! Just to be clear, was the display assembly (p/n 2454039) unavailable from Fluke directly or was it just too expensive? The meter is discontinued, but just recently and I would expect it to still be supported.

author: ASEMechanic
author_rank: Newbie
timestamp: January 21, 2023, 05:59:11 am
content: I did find that part in the manual, but there was nothing I could find anywhere on the internet pertaining to the front panel P/N 2454039. Even the VFD part MN25664J itself was severely limited in information. None of the Fluke parts or repair facilities I contacted had anything available.I think the problem is that while Noritake still manufactures the MN25664J VFD, they no longer sell it individually. This severely limits availability of the part. The only way you can get them is attached to one of their controllers. I do have an e-mail into Noritake VFD to see if there's any way to be able to acquire the VFD individually. We'll see where that goes.At least for now, there is a workable solution. My meter has a brandy-new display and I'm a happy camper.

author: gamalot
author_rank: Super Contributor
timestamp: January 21, 2023, 01:14:51 pm
content: Tonight is Chinese New Year's Eve, I gave myself a gift, upgraded my Tektronix DMM4040 to Fluke 8846.Just about half an hour ago, I happened to see this topic, and then saw that someone had uploaded firmware to xDevs.com, so I decided to try my luck.Now I am very happy, as you can see in the pictures it can correctly measure capacitance and temperature, those are not features of DMM4040 nor 8845.Thank you so much everyone!

author: ASEMechanic
author_rank: Newbie
timestamp: January 21, 2023, 03:37:05 pm
content: Wow! That's pretty cool. I didn't even realize that you could upgrade the meter by just changing the firmware. I guess it makes sense, though. All the hardware is there, just need the right software.Yeah, I downloaded everything xDevs had on their site for the Fluke 884x meters. From the address where you downloaded the firmware, just enter the directory address without the filename. The directories allow indexing so you can see everything in there. Then it's just Right-Click and Save As. You won't be disappointed!Since 8845s go for less than the 8846 (some as low as $700), I may try to pick some up and upgrade the firmware in them.Good luck and enjoy your new meter.

author: analogRF
author_rank: Super Contributor
timestamp: January 21, 2023, 03:44:41 pm
content: dmm4040 does have the USB while Fluke 8845A does not so in that regard dmm4040 is closer to 8846A/dmm4050If I am not mistaken the boards on 8845A and 8846A are not identical. Well, they are but there are a couple of missing chips on 8845Awhich might be the USB controller. I might be totally wrong...I have not seen the inside of DMM40xx....

author: ASEMechanic
author_rank: Newbie
timestamp: January 21, 2023, 03:59:19 pm
content: Quote from: analogRF on January 21, 2023, 03:44:41 pmGotcha. Well, it was a thought anyway.As it turns out, Noritake Elec. *WILL* sell just the MN25664J display directly through them. 8-12 week lead time and ships directly from Japan. Price? $153.00 for 1-9 units and $135.20 for 10+ units.Anyone with weak displays interested in a group buy??

author: alligatorblues
author_rank: Regular Contributor
timestamp: January 22, 2023, 07:17:48 am
content: Quote from: Johnny10 on October 06, 2018, 06:40:45 pmIf you send a 884xA in for calibration (~200$), Fluke will make any small repairs necessary at no charge. Last one I sent in they reflowed the solder joints on front terminals, and updated to latest firmware, both at no charge. But you must have Fluke put on the quote to update firmware, or it might not get done, as was the case with a different meter I sent in for cal.. I had to send it back to get the firmware.Fluke does not give out firmware, because if you buy the front cover, keypad, and what not, you can make a 8846A from a 8845A. They are nearly identical, except for the cosmetics and firmware. If you complain about no free firmware, Fluke will just tell you to shove it, like, "We're Fluke. We don't have to care. We have no competition."They've even done some minor repairs on 732Bs when I sent them in for cal..

author: gamalot
author_rank: Super Contributor
timestamp: January 22, 2023, 08:14:49 am
content: Quote from: analogRF on January 21, 2023, 03:44:41 pmThe difference between DMM4040 and 8846A I can see from the outside is the color of the case, front bumper, handle, and the printing on the front panel (including the glass window and buttons).I opened the case to see what's different inside (clear the dust by the way), and I saw an 8846A mainboard inside my DMM4040.I uploaded some pictures here, you can also find high-res pictures of the board on githubhttps://github.com/gamalot/DMM4040-Pictures.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 22, 2023, 08:20:22 am
content: They have tighter specs for the 8846 compared to the 8845. So there can also be differences in the quality of parts (e.g. better selected resistors or reference) and maybe testing of the whole PCB (those that did not so well in the tests get used for 8845). From the outside a new LM399 looks the same as one with a 3 month burn in and tested for noise.

author: gamalot
author_rank: Super Contributor
timestamp: January 22, 2023, 08:59:52 am
content: Quote from: Kleinstein on January 22, 2023, 08:20:22 amI'm sure they'd save the money if they could.---You can see that J10 and J13 are populated in the picture of Illya's 8846A, but not in my DMM4040.

author: analogRF
author_rank: Super Contributor
timestamp: February 21, 2023, 10:26:14 pm
content: Quote from: gamalot on January 21, 2023, 01:14:51 pmi am still wondering how this could have worked? FW for 8845A and 8846A are the same, also the FW for 4040 and 4050 were the same so I think there must be something on the board or in the flash that identifies the model number and it should not be erasable and modifiable by a FW upgrade...So did the fluke FW complately erased the flash including whatever identified the unit as dmm4040 and replaced it with 8846A?Do you see FLUKE logo at startup now?

author: gamalot
author_rank: Super Contributor
timestamp: February 22, 2023, 08:44:33 am
content: I think all the information is overwritten during the firmware update, except the calibration data.

author: analogRF
author_rank: Super Contributor
timestamp: February 22, 2023, 11:32:41 am
content: Quote from: gamalot on February 22, 2023, 08:44:33 amdo you know what was the OutG FW version of the unit originally? was it below 2.10?and one last question, are the Cap and Temp measurements in spec? They should not be I guess...

author: gamalot
author_rank: Super Contributor
timestamp: February 22, 2023, 04:07:47 pm
content: I don't remember the exact original version number, but I'm sure the original DMM4040 firmware had a higher version number than the 8846A I flashed into it.As for the capacitance and temperature test functions, of course they have not been properly calibrated, and some default values should be used. I found some capacitors and tested them. I can see that comparing the 34465A and the LCR meter, the results of the DMM4040 have very large errors in certain ranges. I didn't do temperature measurements because I don't have the right equipment.

author: Miti
author_rank: Super Contributor
timestamp: February 23, 2023, 07:09:11 pm
content: I can see in the xDevs hi res pictures, there are two SOIC8 ST devices with labels on top. I assume they are configuration devices for the FPGAs. Has anyone tried to dump those and compare a good one with a bad one? Is it possible that something is corrupt there?

author: charlyd
author_rank: Frequent Contributor
timestamp: August 31, 2023, 11:04:58 am
content: Hi is there any progression on the bootup...initializing...... error?