hybridfree/eevblog-posts huggingface dataset:
Does the beam finder on the 7904 increase trace intensity? - Page 1
Forum section: electronics / repair

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: June 12, 2024, 07:00:03 pm
content: Hi,I have a 7904 that I think may have a faulty beamfind. The issue is that the z-axis does not brighten up when the button is depressed.When I look at the schematic, I can see something going off the the z-axis logic IC, but I can't figure out whether that means it should intensify or not. Theory of Operations and how to use doesn't tell me anything either on the intensity part.So does the beam find on the 7904 intensify the trace?Thanks,Benjamin

author: wn1fju
author_rank: Frequent Contributor
timestamp: June 13, 2024, 12:41:58 am
content: On my 7904, the intensity does not change with the beam finder. All I get is a shrunken down display that is out of focus (although the numerical readout stays focused).

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: June 13, 2024, 01:30:45 am
content: That is the exact same thing that my 7904 does. I guess it's safe to assume that my 7904 doesn't have any faults.Thank you!
Does this look like a fuse - Page 1
Forum section: electronics / repair

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: December 15, 2024, 07:57:10 pm
content: While troubleshooting a power supply I found two of these that indicate open. I’m guessing they are fuses. The same ones on a different operating channel are dead shorts. Anyone happen to have a schematic for a R&S 3040 power supply channel?

author: Harry_22
author_rank: Frequent Contributor
timestamp: December 15, 2024, 08:01:38 pm
content: Hi!Is it R&S power supply? It also has Fast 7A in parallel.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 15, 2024, 08:02:57 pm
content: Yes, that's a fuse

author: fzabkar
author_rank: Super Contributor
timestamp: December 15, 2024, 08:05:30 pm
content: Quote from: Ground_Loop on December 15, 2024, 07:57:10 pmThe logo belongs to Littelfuse.https://www.google.com/search?q=Littelfuse+7a+smt&num=10&newwindow=1&udm=2

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: December 15, 2024, 08:09:39 pm
content: Quote from: Harry_22 on December 15, 2024, 08:01:38 pmYes. Channel 4 crapped out. Both fuses are gone. You sure it’s parallel?
Dolch MegaPac, No Video - Page 1
Forum section: electronics / repair

author: simba15
author_rank: Regular Contributor
timestamp: August 10, 2023, 04:01:29 pm
content: Hi there EEVblog,So I recently acquired a Dolch MegaPac (Yes huge "Portable" beast) with a nice set of cards and what looks like Pentium-200 cpu.The frustrating part is that it seems to have no video output (internal LCD or external monitor) even though it sounds like it has completed the POSTOnce powered up:Fans start, power led lit, HDD led litKeyboard indicators flashpost beep is audible, then memory tick counter.Floppy drive seekHDD led Turns offthen a Dudh-dudh sounds is heard ( I suspect this a secondary error like NO Bootable Drive or Bios Checksum Error.Numlock, scroll lock or caps lock doesn't function (even with external keyboard)Strange part is there is no video. Nothing on the internal LCD (not even a backlight flicker) or on the external connector.If I remove the RAM then power up, the device just gives a constant single beep tone to indicate no memory.Is it possible that my modern monitor cant display some basic low resolution?Anyone have any ideas what else I could test for a functional output from the pc ( thinking to probe the VGA connector for sync signals)Pictures and possible video to come soon.Thanks.

author: simba15
author_rank: Regular Contributor
timestamp: August 11, 2023, 06:41:52 pm
content: So in typical vintage electronic fasion I was poking around checking all the voltages. All were OK I tried to measure the sync lines on the vga port and they were driving high. Then all of a sudden the "Du-Du" noise was not present at boot, the sync lines has pulses and the lcd was alive!No idea why as nothing changed, but typical unplug and plug back in and all was working as it was new.Here are a few pics. not sure what i should do with it next, I think I have some 30 pin simms around to upgrade to 32mb or so. or do i gut it and make a modern portable system (even just keep the front panel and use a PI)

author: m k
author_rank: Super Contributor
timestamp: August 24, 2023, 12:50:39 pm
content: Maybe the power overloaded when more juice was required.Then some old caps decided to start co-operating.Did you disconnect all disks before the picture?
Dolch Pac 65 - Corrupt Video Output - Page 1
Forum section: electronics / repair

author: Tony_G
author_rank: Super Contributor
timestamp: August 17, 2024, 08:01:30 pm
content: Hey All,Before I head out and buy a PCI or ISA video card to test, I thought I might ask here if anyone has dealt with this before.My DolchPac 65 seems to have a video issue - I've removed all the cards, the LCD driver panel and the unit seeks the floppy drive so I think it's posting. This is what I see on the motherboard VGA output:I really think that the issue is going to be in the motherboard video (which will basically mean a swap of theCI6BM SBC) but I'm open to any suggestions - Including a new SBC, just need it to support PCI and ISA cards as I'm using the unit to run a HP Viper ISA card in it)Thanks,TonyG

author: Tony_G
author_rank: Super Contributor
timestamp: August 17, 2024, 08:56:07 pm
content: Just an update - I managed to find a old machine here that had a Diamond Multimedia PCI VGA card in it so I grabbed that, dropped it in and the machine posts correctly.Looks like the video part of the CI6BM has failed, which is annoying unless anyone has a suggestion of addressing it as those boards are going for "collector" money apparently...TonyG

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 18, 2024, 01:02:44 am
content: I remember curiousmarc messing with Dolch earlier.Probably a solder crack somewhere. This is common with these long PICMG SBCs.I suppose you could re-solder the chipset, but it is probably a BGA. Difficult to do.It would be better to buy a new full size PICMG 1.3. But finding a compatible one may be difficult.

author: Tony_G
author_rank: Super Contributor
timestamp: August 18, 2024, 01:37:55 am
content: Thanks - It is a "billion" pin package so I'm not even going to try and source a replacement.I did try pressing on the board to see if anything changes but that wasn't successful.I think you're right and I'll need to source a replacement. Thanks again though for the reply.TonyG
Dometic SinePower DSP 1812T Inverter - Page 1
Forum section: electronics / repair

author: smilgy
author_rank: Newbie
timestamp: September 27, 2024, 04:39:29 pm
content: Hey All,I have a Dometic DSP 1812T 1800W inverter which has no 230V output. Previous owner said they plugged in a 2300W kettle and then it stopped working. Initial symptoms were no 230V output, however the unit would turn on, and internally some relays clicked.I've taken it apart and found a manufacturing fault where the manufacturer forgot to put in some screws to attach the input DC side mosfets to their heatsinks. Naturally, these failed. I have replaced these along with some nearby SMD 22R1 resistors. I've replaced all 12 of these mosftets and resistors. Putting it back together, the inverter shows a little more life, there is now an output on the AC side, but after about 10s, a relay clicks and the output is turned off. Measuring the output, it measures about 145V on a true RMS meter, or 270V on a cheap DMM.When the output is turned off after approx 10s, you can very faintly hear a sort of clicking or ticking noise (but not a relay!) from around the step up transformer area. I've marked it red on one of the photos.I've done a reasonably thorough check of most components for shorts, but cant find anything obvious. I have a thermal camera, some basic meters, but unfortunately no oscilloscope.Any thoughts on where to go next? Apart from this fault, the unit is reasonably new and wouldn't have had much use.

author: indeterminate
author_rank: Regular Contributor
timestamp: September 27, 2024, 09:54:35 pm
content: Replace the gate drive ic's

author: smilgy
author_rank: Newbie
timestamp: October 04, 2024, 03:47:40 pm
content: Quote from: indeterminate on September 27, 2024, 09:54:35 pmI've had a look at the gate drive IC, and I'm not 100% sure that it is malfunctioning/bad. Its a TI UCC27324DR cirlced red on the photo attached.https://www.ti.com/lit/ds/symlink/ucc27324.pdf?ts=1727981526281&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FUCC27324%252Fpart-details%252FUCC27324DRThere doesn't appear to be any shorts on it, and thermal image doesn't show it heating out of the ordinary. However, I may order one and replace just to see.
DONT THE PROBLEM DC/DC! - Page 1
Forum section: electronics / repair

author: qttr3566
author_rank: Newbie
timestamp: August 26, 2020, 03:13:48 pm
content: Have no idea about any of this, wont act like i do. Is it possible to see the problem by looking at this dc/dc board? I know it fried just by the brow spot. It is hooked up to two car sized batteries, this cannot change because that is the power need to operate the machinery. Is it possible to fix this board? or a way to improve it? Photos attached below.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 26, 2020, 05:31:33 pm
content: any markings like model / brandwhere does it go : car tractor truck ?? you dont give any details ... my crystall ball doesn't work

author: Gyro
author_rank: Super Contributor
timestamp: August 26, 2020, 06:49:09 pm
content: From the quality of your description of the device and the problem, it doesn't seem likely that it would be possible to talk you through any sort of fault finding or repair.That doesn't mean that it is "Garbage" (or repairable) - it means that you need somebody else who can actually touch it and understands electronics to be able to tell you.

author: qttr3566
author_rank: Newbie
timestamp: August 26, 2020, 08:20:30 pm
content: It gets power from 7-way plug on a trailer that could or could not have been sitting for some time. The idea is that when plugged in it boosts the voltage and overcome any drop (circuit is over 60 ft long) for the batteries to fully charge and operate the lift-gate (13.8 volts at least) on the back of the unit. This converter is a single plug 20 amp. It is a product sold by Purkey (they focus on trailer/reefer lift gate products) but Eaton is the company that makes it for Purkey. I Know everything about the surrounding equipment this converter connects to (Thankfully to my crystal ball). Reached out to the company and they tell me its installation error. That's not possible because we have gotten trailers that needed these replaced after their team installed it.Back to your crystal ball though. Have you tried Windex?

author: Gyro
author_rank: Super Contributor
timestamp: August 27, 2020, 06:43:44 pm
content: Unfortunately it still doesn't seem likely that we can make a remote diagnosis from just the photos. There are clearly through-hole components on the other side of the board, probably connectors too, as I can't see any on the visible side, which might prevent removal without un-soldering.Itcouldbe something as simple as a blown or dried out through-hole electrolytic capacitor, but without disassembly, close visual inspection, and test that's no more than a guess.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 28, 2020, 07:22:51 am
content: I hope it's not potted / gunked ... but the way it is it wont go further in helping youYou'll have to dig out the board and take some photos of the other side ...And or try to use another dc/dc brand / model ....
DOOSAN Lighthouse V9 generator blows rotor diodes - Page 1
Forum section: electronics / repair

author: Robski
author_rank: Contributor
timestamp: October 21, 2019, 10:57:27 pm
content: Hi! I have a diesel powered generator that keeps blowing the diodes in the stator. The oryginal ARD25M button type diodes were just melting the solder. I've replaced two aut of four of them with P2500Y type and after starting the generator and turning the load on, they split through the middle.Have you guys any suggestions?

author: amyk
author_rank: Super Contributor
timestamp: October 22, 2019, 02:17:10 am
content: Are you overloading it? Is the voltage regulation OK?

author: Robski
author_rank: Contributor
timestamp: October 27, 2019, 08:35:39 am
content: I am not overloading it. It is connected to 4 1000W spotlights and there is no option to connect the external load.I managed to sort out the issue of diodes blowing up by replacing all of them. However, there seems to be a problem of nature I don't understand completely.After starting the engine it generates only about 40V until I turn on all the lights. After a few minutes, diesel runs stable and lamps draw 22A but after 5-10min of running it starts slowing down the RPM and current goes to 30A and keeps rising. Checked the sinewave with the oscilloscope and it looks pretty good to me.What could cause that kind of an issue?

author: amyk
author_rank: Super Contributor
timestamp: October 27, 2019, 07:03:00 pm
content: Temperature-dependent partial short?

author: hermit
author_rank: Frequent Contributor
timestamp: October 27, 2019, 07:30:06 pm
content: Some manufactures are more helpful than others. Have you contacted them? Shouldn't hurt to try.

author: floobydust
author_rank: Super Contributor
timestamp: October 27, 2019, 07:49:59 pm
content: The generator is aMecc Alte LT3−130/46kVA 230VAC 50Hz. I think it's 4-pole.It has abig capacitoras part of regulation, I would check it. It should be 31.5uF and when running 2.3A flowing. Measure your output voltage as it goes from 22A to 30A, that seems weird unless output voltage is skyrocketing to the lamps.The rotor (3.88R), stator (0.385R), excitation (1.88R) winding resistances I would also check, in case the windings overheated and have shorted turns.
Doulbe-sided codes on Tantulum capacitors - Page 1
Forum section: electronics / repair

author: Bobertsawesome
author_rank: Regular Contributor
timestamp: August 19, 2020, 05:30:00 am
content: Hi there,This one stumped me as I have never seen this marking method before, nor could I find info on the web regarding a double-sided code marking.1st side 104-e5m , 2nd side 720-rac (same capacitor)I assume it is 100nf, but not sure what or how to find the voltage rating. Included here are the photos for relevance:

author: garrettm
author_rank: Frequent Contributor
timestamp: August 19, 2020, 06:20:03 am
content: I believe that is a ceramic capacitor, not a tantalum. Tants have a polarity marking which this part does not have.100 nF sounds right: 104 => 10*10^4 pF = 10*10^-8 F = 100 nF.As to the voltage rating, good question. I couldn't find anything for e5m or RAC as a part name. Those also don't line up with the voltage/tolerance codes either.Regardless, what is the measured voltage in circuit? Assuming it was derated 20-50%, that at least gives you a start.Are you replacing a bad part or something else?

author: fzabkar
author_rank: Super Contributor
timestamp: August 19, 2020, 06:24:16 am
content: E5M appears to be a temperature coefficient.https://www.ebay.com/itm/10pcs-Ceramic-Capacitor-50V-1uF-20-E5M-Radial-NOS-Free-Shipping-USA-/154017117597https://en.wikipedia.org/wiki/Ceramic_capacitor#Class_1_ceramic_capacitorshttps://electronics.stackexchange.com/questions/241232/what-does-the-3-figure-code-below-the-value-code-mean

author: Bobertsawesome
author_rank: Regular Contributor
timestamp: August 19, 2020, 07:19:03 am
content: Quote from: garrettm on August 19, 2020, 06:20:03 amYou are definitely correct, it threw me off considering the rest of the caps are tants. The circuit is fine, needed some minimal repairs due to degradation over 25+ years. Figured I'd recap at the time too. I suppose I'll just check the voltage to the cap, but was wondering more in the long run what the dual codes meant.
DPO 4104 fried - can it be repaired - Page 1
Forum section: electronics / repair

author: Javaslinger
author_rank: Newbie
timestamp: July 15, 2021, 01:07:36 pm
content: I'm a chemist who unfortunately has to use a very very very expensive oscilloscope to diagnose NMR equipment running up to 600Mhz. I need to be able to see the signal and do very basic things like measure frequency and peak to peak voltage. Due to the frequency, I have to use pro level scopes.We have been using a Techtronix DPO 4104 until I blew it out by forgetting to attenuate the signal coming out of the amplifiers. Well, 10 years before I made the ultimate mistake is a good run, right??? 300W and the screen cut out with a nice burnt smell emanating from the unit.I'm curious if anyone has any experience getting is sort of damage repaired and what kind of cost I would be looking at?

author: rsjsouza
author_rank: Super Contributor
timestamp: July 15, 2021, 01:41:21 pm
content: Well... It was indeed a good run.If the oscilloscope does not turn on again, from your description it was something more than a simple 50­ ohm termination resistor in the analog front end.Ideally you would open up and try to visually see burnt components, boards, etc. That would go a long way to identify the root cause of the issue (post pictures here so others can try to suggest actions to take).That does not leave you out of the hook for actually executing a repair and more advanced diagnostics in case the burnt component is not the only damaged one (which I don't think it is, as per your description).If your workplace/lab has some sort of repair contract, that would be a good time to use it. if all else fails, tap into the finance department to get a capital expense approved for a new unit (the DPO4104 is long out of production).Good luck in your investigation.

author: bdunham7
author_rank: Super Contributor
timestamp: July 15, 2021, 01:43:30 pm
content: I have experience repairing many similar things, although not the DPO4104 specifically. If you energized the input to the point that the screen shut off, the damage is likely to be very severe. I don't know whether Tektronix will still service this, but if they will it will be eye-wateringly expensive. I suspect parts availability will be an issue by now--when I run into things like this I usually just have to wait until a parts unit or parts become available from secondary sources, like eBay. That can take months or years. There's no harm in having someone take a look (unless they charge you a lot up front) but I wouldn't be super-optimistic about it being a quick fix.If you want to specifically stick with the DPO4104, your best bet would be to buy a used one, then sell your burnt one for parts on eBay. If you don't need the DPO4104 specifically, there are other scopes on the market now that can do a pretty good job up to 1GHz bandwidth.What were the characteristics of the signal you were putting into the scope? Is it high voltage? Do you normally use the 50 ohm input setting?
DPO3000 BNC ID - Page 1
Forum section: electronics / repair

author: Jwalling
author_rank: Unknown
timestamp: September 11, 2019, 02:33:12 pm
content: A friend is trying to source a replacement BNC for a DPO3000 scope. I've not come across this one before, does anyone have an idea on the part #?Thanks!

author: Jwalling
author_rank: Unknown
timestamp: September 12, 2019, 07:02:05 pm
content: Reply from Amphenol:Quote
DPO4054 trace shift in 50 ohms  - Page 1
Forum section: electronics / repair

author: hitecelec
author_rank: Regular Contributor
timestamp: December 13, 2019, 10:28:33 am
content: HiI have a DPO4054 that is exhibiting substantial trace shift in channel 1 in 50 Ohms modethe gain is improper in 100mv, 200mv less by about 25 %. At 500mv and 1V the trace goes out of screenChannel 1 works ok in 1 Mega ohms modeOther channels l are functioing ok.Any hints welcomethanks in advance

author: ArcticGeek
author_rank: Regular Contributor
timestamp: December 13, 2019, 02:45:16 pm
content: I've never seen this occur on a DPO4054 but I have seen it a few times on a TDS3054, and both times I observed this behavior it turned out the the 50 ohm attenuator inside the scope was fried (most likely from overload). Is the channel 1 input really 50 ohms when you put it in that mode? You can check it with an ohmmeter and it should measure 50 ohms +/- 1%.

author: RomDump
author_rank: Regular Contributor
timestamp: December 13, 2019, 07:08:33 pm
content: This may be obvious, but let the Oscilloscope warm up for 30 minutes then run the SPC and see if it resolves the issue.

author: hitecelec
author_rank: Regular Contributor
timestamp: December 17, 2019, 09:57:47 am
content: hellothanks for the inputs. will try and revert

author: jmelson
author_rank: Super Contributor
timestamp: November 09, 2020, 12:25:04 am
content: Quote from: ArcticGeek on December 13, 2019, 02:45:16 pmYes, my boss has now blown out two channels on our DPO4054 this way. Is this something that can be fixed by a reasonably handy guy with SMT experience, or can it ONLY be fixed by Tektronix? They quoted us $1000 to just LOOK at it a while ago.Thanks,Jon

author: ArcticGeek
author_rank: Regular Contributor
timestamp: November 09, 2020, 12:56:00 am
content: I doubt that it will be an easy fix, even if you are skilled at SMT soldering. The 50 ohm attenuation is usually part of the attenuator itself, and it would likely require a complete replacement of the attenuator module. I don't have a DPO4054 to say for sure, but that would be by best guess as to what you will find.Good luck!

author: mikehank
author_rank: Regular Contributor
timestamp: April 04, 2022, 03:34:18 pm
content: The DPO4054 does not have a 50 ohm attenuator. 90mv and down is a strait shot into the 50 ohm preamp. 100mv and up goes though a r/c bridge. It is possible that only a few resistors are damaged but not sure.
DPO7054 - Page 1
Forum section: electronics / repair

author: phoenix1988
author_rank: Newbie
timestamp: February 06, 2023, 10:43:11 am
content: Hello, I have a question about the DPO7054 oscilloscope. When the device is turned on, there are 2 fans on the left side panel, only 1 works. I measured the voltage, it is only on 1 connector. Question: is ventilation implemented here so that one fan works first, and when the temperature increases, both, or is my oscilloscope not working properly? Thanks

author: inse
author_rank: Super Contributor
timestamp: February 06, 2023, 01:16:18 pm
content: As far as I remember the fans are speed controlled, so the rpm pulses would also be monitored.Is it possible to check the fan speed in the BIOS?

author: phoenix1988
author_rank: Newbie
timestamp: February 06, 2023, 01:51:43 pm
content: D.h beide Fans sollen funktionieren mit verschiedene Temperatur (je mehr die Temperatur, desto größer Geschwindigkeit haben Fans) , oder eins fan bei kleine Temperatur beide bei höher Temperatur.

author: mikehank
author_rank: Regular Contributor
timestamp: February 06, 2023, 08:25:53 pm
content: Both fans are controlled separately bi the PowerPC board. These fans pull air up though the acquisition board from the bottom to cool the board. Both will need to be working for reliability.On the PowerPC board there are a couple of transistors near the fans I can't remember the reference designators but these commonly cause fan issues.

author: inse
author_rank: Super Contributor
timestamp: February 07, 2023, 07:04:04 am
content: I just have checked with the DPO7054 here at work: only the top fan spins up at startup.

author: mikehank
author_rank: Regular Contributor
timestamp: February 07, 2023, 10:44:19 pm
content: The fan driver issue is pretty common. Several reasons exist why the control circuit gets in trouble..1) if the covers have been removed with the feet. If a DPO7K does not have proper bottom ventilation it will overdrive the fans to keep it cool.2)1 fan does go out the second will try to keep up damaging the circuit3)one of the ASIC's on the acquisition board has a broken ball reporting an over temp condition or no status condition. Usually this issue involves a DEMUX.4)build up of dust and crapI have seen this issue dozens of times in the past super common.
DPO70804 OS restore - Page 1
Forum section: electronics / repair

author: Earendil
author_rank: Regular Contributor
timestamp: December 01, 2019, 07:44:43 pm
content: Hello,I purchased a used Tektronix DPO70804 oscilloscope without a hard disk and without any OS restore media. I also managed to purchase a MSO70000 Series Operating System Windows XP Embedded Recovery Media DVD which I hoped to work with my DPO70804 however I get the following error message when I try to boot from it:"Starting Acronis Loader... Unable to proceed. A non-To Be Filled By O.E.M. system found. This software can be used only on To Be Filled By O.E.M. computers. Press <Enter> to reboot..."It's not clear if this means that this software will only work with a specific type of hard disk or it means that this DVD is not compatible with my oscilloscope. In any case I managed to restore the included .TIB file with Acronis True Image 2020 on my PC to a hard drive. I managed to boot from it but unfortunately Windows XP cannot find and install certain drivers (it keeps asking for them, like Video driver, SM Bus, etc). Some of the included Tektronix drivers seems to work though (touchscreen works for example). I also managed to install the firmware (TekScope) to this Windows XP and it even seems to work to a certain extent (I can see some waveforms). However the problem is that the physical knobs doesn't work on my scope.Has anybody seen and managed to fix the Acronis error I mentioned?Can somebody share a working restore image please?
DPO7104 selftest errors repair - Page 1
Forum section: electronics / repair

author: pasta2018
author_rank: Regular Contributor
timestamp: May 10, 2025, 08:29:35 am
content: Recently I got another DPO7104 scope.1.I reinstalled the operating system with some other DPO7104 back up OS.2.It reports 8 errors after excute selftest.3.This board is 2 DACs with no track hold chip version4.I checked the four resistance on the acquistion board, three of them are right. The 430 ohm resistant I measured in different directions are 370 and 400 ohms respectively. Is this a problem?5. Some drivers are not installed.6.In the console log, seems error point to U10_A U10_B U11-0-A U11-0-B etc.Can you give some advice where to check next?

author: pasta2018
author_rank: Regular Contributor
timestamp: May 10, 2025, 08:37:04 am
content: attached console log here
DPO7254 Acq Board Mechanically Intermittent - affects all channels. - Page 1
Forum section: electronics / repair

author: dmeeks60
author_rank: Newbie
timestamp: April 15, 2024, 05:47:19 pm
content: Hey group -DPO7254 first starting having intermittent offset issues (zero was off by quite a bit). Running SPC used to take care of it.Then SPC stopped working - fails during test - but all channels were still useable.Now it's gotten all sorts of wonky. Moving position sometimes the trace doesn't "follow". Had one channel just flat-lined, didn't show any vertical.Then all channels dead. Sometimes one channel has random noise on it but other channels work. When a channel is out, sometimes it's the only one out and one or more of the others are still working more-or-less.Sometimes when a channel is "working" the amplitude is wrong (low) like it's being compressed or clamped.I found that tapping on the Acq board made it pop in and out. So it is something mechanical or maybe bad solder on something.i am begging here for advice from anyone that has knowledge of this board.Since it affects all channels it must be something common to all channels, so I want to narrow down the suspects based on that.I am going to consider reflowing the chip(s) most likely to be the issue.Or if anyone has a good acq board for this series I would be interested in purchasing it.Thanks in advance.Dan

author: charlyd
author_rank: Frequent Contributor
timestamp: June 17, 2024, 02:13:46 pm
content: Hi maybe problems in your inter-board connectors/connections?

author: calibrationfixture
author_rank: Regular Contributor
timestamp: June 17, 2024, 02:42:58 pm
content: Hi charlyd,A bit overdue with your advice. See:https://groups.io/g/TekScopes/topic/105563180#msg204555Calibrationfixture

author: coromonadalix
author_rank: Super Contributor
timestamp: June 17, 2024, 03:15:49 pm
content: would be nice to know when question(s) have already been posted elsewhere .....it's like two timing ...thks @calibrationfixture

author: charlyd
author_rank: Frequent Contributor
timestamp: December 08, 2024, 07:08:54 pm
content: It s a while ago and now i saw groups.io/.too. @dmeeks60 what happened exactly, did you fix or get it fixed...if so tell us what was done.i have a DPO7254 staying arround where the ACQ board is waiting for a BGA chip before putting it into the soldering machine.and an other one with problems. (error 316 where sine see other post here on evvblog..) so these unit fail easily and not much found on themall info from those series is usable.so please post...
Dr. Meter HY3005F-3 Power Supply Display Issue..  - Page 1
Forum section: electronics / repair

author: KG7AMV
author_rank: Frequent Contributor
timestamp: February 02, 2020, 04:21:51 am
content: I just got a HY3005F-3 off ebay.. in the other day!!Looks like it was damaged in shipping. (I have my doubts but what the seller claims) It had a smell of magic smoke upon opening the box!! The seller refunded no return label and said he would take it up with ups.. So I will assume the seller was telling the truth..Anyways, Now it looks like I get a tear-down and a project!One Channel displays max 14V but the output is 31V LOL...Found it the mastech schematic on another thread it is part for part so far on the display part for the voltage section.. less C43https://www.eevblog.com/forum/testgear/mastech-hy3005f-3-seriesparallel-switches-imply-non-floating-supply/msg492343/#msg492343Here is a You Tube Video.. of its Issue..https://youtu.be/TORUWRbDTbcHere is the part not on the schematic that let the magic smoke out. After Cleaning Labled C43 could be seen clearly.. This PSU has been messed with rubycons installed.Quick Reference Display Schematic.After Probing Around Found an interment short on C7 Removed C7 low and behold the display go all the way up?So Looking at the HEF4069UBT may be faulted cap tests good? Cap tested Good Installed another know cap same issue.. Checked D1 & D2 Also Good.

author: KG7AMV
author_rank: Frequent Contributor
timestamp: February 26, 2020, 10:59:09 pm
content: Anyone put 10 turn pots in one of these? If so part #?
DR TALBOTS INFARED THERMOMETER - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: November 28, 2021, 03:23:01 pm
content: Hi all i have a doctor .talbots ir thermometer,i brought it cheap as not working,it lights up and seems to measure ok,it has what looks like a mirrored concave with some sort of sensor behind it,mounted above the mirrored reflector looks like a lased diode,if its a laser it cant be seen to work,i got this to check a faulty ebike battery to look for different temp 18650 cells,i assume it has a red laser diode to aim it?,any clues welcome.TIA

author: TheMG
author_rank: Frequent Contributor
timestamp: November 29, 2021, 02:28:51 pm
content: Yes the purpose of the laser is only to aid in aiming.

author: m3vuv
author_rank: Super Contributor
timestamp: November 30, 2021, 06:37:33 am
content: well in that case the laser part of mine is dead,as nothing lights up at the front of the unit,just the lcd display at the rear !
DRANETZ PowerGuide 4400 CF 50-PIN Broken Connector - Page 1
Forum section: electronics / repair

author: tpd
author_rank: Contributor
timestamp: June 23, 2023, 01:33:31 pm
content: Hi,Can you recommend a replacement for Kyocera 5620A 50 PIN Right Straight Eject connector in picture (it is discontinued)?I think that pitch should be 1.27 mm.Best regards and thanks
Dranetz PowerGuide 4400 / Mavowatt 30 Faulty Touch Screen - Page 1
Forum section: electronics / repair

author: tpd
author_rank: Contributor
timestamp: May 17, 2023, 09:21:04 am
content: Hi,Unfortunately I bought a faulty Dranetz PowerGuide 4400 instead of "100% functional", it seems that touch screen is not working (it has a nasty scratch on the upper right corner of display), the rest of it could be functional. The same display and touch screen has Metrawatt's Mavowatt 30, so, I suppose, it could be used as spare part. Neither Dranetz, nor Metrawatt sell spare parts, as well there is no sense to repair it officially, I need an information regarding touch screen for any of these devices. Does anyone knows which touch it is, or have a new/used one?Best regards and thanks in advance.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 17, 2023, 10:10:51 am
content: Normally when possible you open the unit and check all markings on the lcd if there is any ... the flat cable width / pin counts, driver ic's etc ...internal pictures ...without that, it's guesstimating

author: tpd
author_rank: Contributor
timestamp: May 17, 2023, 10:13:41 am
content: Thanks, it is still sealed, I replied for refund at eBay, it it fails I can break the seal.

author: TizianoHV
author_rank: Regular Contributor
timestamp: May 17, 2023, 10:39:23 am
content: Maybe some bumps during shipping caused a connector to loose connection. My mavowatt 45 (bought broken) had broken solder joints and lots of loose screws.Have you tried bumping it, like with old TVs?

author: tpd
author_rank: Contributor
timestamp: May 17, 2023, 11:12:41 am
content: Yes, bumping didn't help, this scratch could be the cause for touch screen malfunction, but I'm not sure. From time to time screens are changing without my help, Dranetz is extremely slow, maybe it is just dyeing, it is 15 yrs old.

author: tpd
author_rank: Contributor
timestamp: May 18, 2023, 08:23:57 am
content: Suddenly it start working, a miracle. It is working, but it is slow somehow and "buttons" need to be hardly pressed in some regions of display to work. Maybe it is because it is a 15 yrs old device, or is it still related with partially defective touch screen? Any ideas?

author: coromonadalix
author_rank: Super Contributor
timestamp: May 18, 2023, 10:43:19 am
content: could be the touch screen components who have hardened or physical phenomenon for its age ....not sure if you can call a screen calibration routineit could help a bit

author: tpd
author_rank: Contributor
timestamp: May 18, 2023, 11:18:41 am
content: thanks, I can use settings, but I doubt that touch screen should ne so hard to "touch". I have to apply a certain pressure on each "button" to activate it, as well reaction is not immediate.
Dreamtech DTM0661 - Page 1
Forum section: electronics / repair

author: goaty
author_rank: Regular Contributor
timestamp: November 26, 2021, 09:21:06 am
content: I got a Dreamtech DTM0661 chip in a Voltcraft OLED clamp meter VC-590.Anyone got at least the pinout of the interface to the MCU ?Its like the DTM0660, but without LCD interface.It´s connected to a EFM32TG842.It hangs up in all AC modes. All other modes work fine.We definitely need right to repair to have some chance of debugging.
Drill charger - Page 1
Forum section: electronics / repair

author: MirtSergiu
author_rank: Newbie
timestamp: May 12, 2020, 12:08:56 pm
content: I have this bosch al 1130cv 10.8v battery charger. It worked fine until one day when it stopped charging. When i insert a battery, it's charging for 3-4 seconds then the relay closes and it shows the constant green light and when i measure the battery voltage, it shows 8.7v. I took a look inside and i couldnt see anything that doesnt look ok. What could it be?

author: aqibi2000
author_rank: Regular Contributor
timestamp: May 12, 2020, 12:38:56 pm
content: Common issue is electrolytic caps

author: MirtSergiu
author_rank: Newbie
timestamp: May 12, 2020, 12:41:04 pm
content: Im thinking that it is recogninzing the battery as fully charged

author: tunk
author_rank: Super Contributor
timestamp: May 12, 2020, 01:22:21 pm
content: Or if the battery has a temperature sensor, it could be broken.

author: MirtSergiu
author_rank: Newbie
timestamp: May 12, 2020, 02:07:05 pm
content: It has a tempereture sensor, but the led should be red it thats the problem

author: Slh
author_rank: Regular Contributor
timestamp: May 12, 2020, 02:24:54 pm
content: Based on a drill battery and charger (not Bosch) that I've just the same problem with I'd say that one of the cells in your battery is dead.I presume that it's for 3 series cells of nominal voltage around 3.6V. Fully charged each cell would be around 4.2V so two good cells is pretty close to your 8.7V.In my case three of the five cells in a 20V pack are charged but two of them are dead shorts and the charger shows the green light for charged. Pack voltage is around 12V as the good cells are fully charged.

author: MirtSergiu
author_rank: Newbie
timestamp: May 12, 2020, 03:23:28 pm
content: I charged the batteries to around 10.5v with a 12v dc adaptor and tge problem was the same

author: Slh
author_rank: Regular Contributor
timestamp: May 12, 2020, 03:48:34 pm
content: Do you have more than one battery pack to test it with? There's nothing obvious in the picture that you showed so I'd want to look at the battery.Alternatively it could just be a dodgy connector or broken wire. You could buzz the wires with a multimeter when it's all disconnected or see if you can measure anything on the battery connections when it's powered on.. I wouldn't recommend probing the charger while it's open so this might not be easy to do. What does it do if you turn it on without a battery connected?Is there anything on the little PCB that you're holding in the picture?

author: MirtSergiu
author_rank: Newbie
timestamp: May 12, 2020, 03:52:50 pm
content: I charged the batteries to around 10.5v with a 12v dc adaptor and i opened their case, tested them and they were all fine. There's nothing on the other side of the small pcb

author: aqibi2000
author_rank: Regular Contributor
timestamp: May 12, 2020, 07:28:19 pm
content: Just why.
drive vacon 100 fault system 8 id 603 - Page 1
Forum section: electronics / repair

author: IngIgn2689
author_rank: Newbie
timestamp: October 21, 2024, 02:59:19 am
content: Hello, how are you?Does anyone have any idea what to check on a Vacon variable speed drive with a system 8 fault ID 603, which says that the auxiliary voltage is too low? I have already checked the voltage at 24 volts and it is ok. The manual does not indicate much, thank you200 hp 480v VFDregards

author: croaker
author_rank: Contributor
timestamp: October 21, 2024, 07:07:13 pm
content: What marking does the VFD have (on the nameplate)?Can you take a photo of the control module?

author: IngIgn2689
author_rank: Newbie
timestamp: October 24, 2024, 02:56:40 am
content: Hi see attached picturePlease let me konw

author: croaker
author_rank: Contributor
timestamp: October 24, 2024, 06:06:09 pm
content: The company Vacon produces many different types of VRF, which one is yours? What is written on the VRF nameplate? Take a photo of the nameplate.

author: Svetcvi
author_rank: Newbie
timestamp: July 29, 2025, 09:57:35 am
content: приветствую. у меня такая же проблема с двумя частотниками, у одного ошибка 8 с номером 603 , и у второго 8 - 604
Driving me mad!!!  - Page 1
Forum section: electronics / repair

author: rfengg
author_rank: Regular Contributor
timestamp: May 12, 2025, 06:19:59 pm
content: Hi All,Have the strangest of problems on one of our Network Analyser instrument repairs. As this is work related, I cannot post any pics but I have drawn out in the figure, in what I consider to be a simple issue but has been driving me madsince Friday last.As shown in the attached pic, I have a PIC uP providing a data signal to a LED display with the ground also on the flex. The PIC has a series 47ohm resistor at its output which is then connected to a flat flex cable of around 20cm.The strange issue I am facing here is that when the flex is connected to an open circuit connector on the left end, the data signal completely disappears at the left end of the cable when scoped while is still present at the right end at the uP end on the scope. I thought surely the FFC was broken , but I checked with a multimeter and I even swapped in 2 new ones but to no avail. I checked the solder connections on the left connector and the continuity of the data pin to the end of the resistor and it all checks out fine; ground connection is also intact. What on earth could be happening here? The only thing I did not check is the 47ohm resistor as its difficult to access but I thought since I am getting a signal after that, the resistor should be good. Any pointers?

author: langwadt
author_rank: Super Contributor
timestamp: May 12, 2025, 06:32:27 pm
content: the FFC is upside down for the connector? some connect on top some on bottom, and some on both

author: rfengg
author_rank: Regular Contributor
timestamp: May 12, 2025, 06:35:34 pm
content: @langwadt No checked that.....again, I get continuity (0.1ohms) from the resistor end to the connector where the flex is soldered , so it's good on that front.

author: neillnz
author_rank: Contributor
timestamp: May 13, 2025, 04:33:33 am
content: Can you remove the ribbon from the uP, attach a 20cm length of hookup wire to your scope probe and touch the other end of the wire to the resistor pad or ribbon socket?Or remove the open circuit connector and place the scope probe tip on the flex contact where it would mate with the open circuit connector.

author: Psi
author_rank: Super Contributor
timestamp: May 13, 2025, 05:41:40 am
content: On the left in the pic, when you check and find no signal, are you sure you are probing the bare copper and not an area that has polyimide over it.Sometimes there are a few different layers of material stacked on top and with different transparency through to the copper.So you can see an area that looks different where the copper tracks are visible and assume that must be where bare copper is exposed, but it isn't.There's another level again where the copper/gold is exposed hidden inside the connector where the pins touchIt can also be cracked and intermittently connect/disconnect and trick you into thinking the problem is somewhere else.
DRTech FDXD-1417 Flat Panel X-Ray Detector - Page 1
Forum section: electronics / repair

author: stdlogicvector
author_rank: Newbie
timestamp: February 15, 2022, 03:02:46 pm
content: Hello!I'm looking for (service) manuals for the DRTech FDXD-1417 Flat Panel X-Ray Detector or the FCB-1417 Control Box.I already tried to get them from DRTech, but they won't provide information, even when sending the request as a companyIt would also be helpful if someone could confirm the assumption that the sensor outputs a CameraLink signal. I suspect the Controlbox hasn't any complicated electronics inside, it just combines power, data and trigger into a single cable. Maybe it has a cameralink repeater inside...I also tried to get information from DAQsystem, a company that seems to have provided USB-CameraLink Framegrabbers for DR-Tech in the past. But they only redirected me to DRTech.I'll get sensor soon, so hopefully I can deduce a bit more when opening it. But any additional info is appreciated!
What a blast (nOOb) - Page 1
Forum section: electronics / repair

author: Zero_Ego
author_rank: Regular Contributor
timestamp: December 03, 2020, 07:05:58 am
content: Hi,Just wanted to say hello. I'm a proud noob. (But fully clothed)I really love how sleek this forum is wow.This is a real thrill to actually be in Dave's EEvBlog forum.Can I purchase a EEVBLOG DMM does anyone use there. (That's a loaded question)Everyone on the globe has them they must be good.Thanks

author: Haenk
author_rank: Super Contributor
timestamp: December 04, 2020, 11:50:36 am
content: "Everyone on the globe has them they must be good."Good, yes, but I doubt most members of the forum have one.(I prefer a bench multimeter, as those pocket multimeters tend to be poorly readable from different angles and ever so often flip over. But for certain tasks, a good pocket multimeter is far better suited, so get a good one...)
ds1052e 1 channel cannot trigger help properly - Page 1
Forum section: electronics / repair

author: weixiuniuniu
author_rank: Newbie
timestamp: April 10, 2025, 12:47:56 am
content: ds1052e 1 channel does not trigger properly and the waveform keeps swinging from side to side, even though the trigger level is within the normal range. However, it is not like the trigger is out of sync. When opening channel 1, the waveform at the red arrow on the drawing is also swinging, and when opening channel 2, the red arrow is normal. Now I do not know how to repair it
2465B  = DS1225Y ... 100ns or 150ns? - Page 1
Forum section: electronics / repair

author: Joseph Bozzer
author_rank: Contributor
timestamp: January 10, 2020, 01:37:39 pm
content: The question is in the title

author: wraper
author_rank: Unknown
timestamp: January 10, 2020, 01:41:51 pm
content: Does not matter.

author: Joseph Bozzer
author_rank: Contributor
timestamp: January 10, 2020, 02:55:45 pm
content: Ok ... I would replace it by a new M48Z08 of STMicroelectronics ... is it good choice?

author: jonpaul
author_rank: Super Contributor
timestamp: January 10, 2020, 03:43:01 pm
content: Joseph, the ST my not be the same, you can get a genuine Dallas from DigiKey, newest versions have a first use battery saver feature.IF bought from other sources beware date code and Chinese illegal copies or pulls.Should cost about EU 20.Jon

author: wraper
author_rank: Unknown
timestamp: January 10, 2020, 04:58:58 pm
content: Quote from: jonpaul on January 10, 2020, 03:43:01 pmIf buying from china, don't believe date code. Most likely will be old re-marked junk with fake date code.

author: Joseph Bozzer
author_rank: Contributor
timestamp: January 10, 2020, 07:27:29 pm
content: In Belgium it's Farnell the most easyI find this :https://be.farnell.com/fr-BE/maxim-integrated-products/ds1225y-150/memoire-nvram-cmos-64k/dp/2518661?st=DS1225Is it good?
DS1230Y-100 Integrated Circuit - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: November 24, 2021, 10:20:52 am
content: can this type of nvram: DS1230Y-100 have the external battery hack/bodge done on them?

author: sicco
author_rank: Regular Contributor
timestamp: November 24, 2021, 01:30:21 pm
content: check outhttps://www.antiqueradios.com/forums/viewtopic.php?f=8&t=352206Not one, but two batteries...

author: m3vuv
author_rank: Super Contributor
timestamp: November 24, 2021, 02:41:08 pm
content: i have already seen that but it doesent realy answer my question does it,thanks all the same tho.

author: m3vuv
author_rank: Super Contributor
timestamp: November 24, 2021, 02:53:31 pm
content: its on a new scope i should get next week,i may pull the ic then grind most of the body away then use a laser to carefully burn off the rest and see what i can rig in the way of batterys to it.