hybridfree/eevblog-posts huggingface dataset:
fluke 83 constant continuity - Page 1
Forum section: electronics / repair

author: glinjik
author_rank: Regular Contributor
timestamp: March 08, 2021, 12:39:29 pm
content: Hi guys anyone any idea why fluke 83 is in constant continuity as soon as i push the button for continuity it goes constant beeping i thought maybe the input jacks were done but even with the input jack block removed same result i have check components cant find a thing the selector switch seems OK I'm baffled all other measurements re normal IM getting to the point of putting it in the bin and getting a uni-t lol

author: ogdento
author_rank: Regular Contributor
timestamp: March 08, 2021, 05:57:10 pm
content: i encourage you to keep at it! these can be a pain to fix but it's very satisfying once you do.if all the other measurement ranges (ohms, volts, etc, and you've verified 10M dcv input impedance) are working than I'd probably start with the piezo driver:if you look at the schematics you'll see U4 pin 15 (signal p23) goes to the base of Q9 to drive the beeper... is the p23 signal turning on/off when you change the continuity button? if so, q11 could be bad. if not, check the other piezo driver bits (see section 2-18 in the service manual)

author: glinjik
author_rank: Regular Contributor
timestamp: March 08, 2021, 07:42:17 pm
content: thank you fo your reply i nave a AVO tt169 here so tomorrow will check all transistors
Fluke 83 LCD repair questions - Page 1
Forum section: electronics / repair

author: alonsojar
author_rank: Contributor
timestamp: May 26, 2022, 05:20:33 pm
content: Hi,I'm repairing a venerable Fluke 83 initial series I've found cheap. It only had minor issues and dirt from 30 service years (main chip is dated 07-90). After cleaning and lubricating the function selector and plug socket, everything seems to work right and very accurate as far as I can verify.The only remaining issue is the LCD screen. The segments are all ok, but the screen is dark shadowed in the borders probably due to any penetrating contaminant. After a close inspection with magnification it looks like the problem is not in the polarized front film but within the back reflective panel.I wasn't able to find any reference on how to perform substitution of back panel (if even possible) or what kind of material should be used (just reflective or polarized too). Since the screen is still readable I wouldn't want to risk it without havinga good success probability...The OEM replacement LCDs for these models (I think 83/85 original series and series iii are compatible) are scarce and expensive here, so I'm not considering this option by now....Should it be possible to replace this reflective panel? Thanks in advance for any hintJ.Alonso
fluke 83 lead warning beeper - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: September 19, 2019, 02:20:24 am
content: hi all i thought id share this,a few months ago my fluke 83v kept flashing lead and beeping on all switch positions,looked on the net about cleaning the probe sockets with ipa and cotton buds etc,nothing worked then i saw the price of a new probe socket assembly,about £28 here in the uk,i thought well nothing to loose so unsoldered the sockets from the meter and trew them in my washing machine wrapped in a sock,dried them in the airing cupboad for a day after and refitted,bingo fixed it sparkly clean and curred the lead warning issue,enjoy 73 m3vuv.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 19, 2019, 03:41:32 am
content: Similar tohttps://www.eevblog.com/forum/repair/fluke-189-teardown-repair/
Fluke 8375 tin whisker - Page 1
Forum section: electronics / repair

author: RolandK
author_rank: Regular Contributor
timestamp: August 24, 2022, 09:54:08 am
content: Because of a hint in the TEA thread i got a 5 1/2 digits (119999) fluke 8375, which of course only showed zeros in the display.For the 8375 i did not find any manual, but the 8300 manual works fine. The 8375 seems to be a 8300 with 10 ohm, 100mV and true rms voltage options (numbers are ranges, resolutions are eg. 1 µV, 100 µOhm) and a better reference (0.002 % vs 0.005 %).The reason for the zeros display was a short between two strip lines on the main pcb which where parallel through the whole pcb about 40 cm / 16 inch. Of course there was at first sight nothing visible. So i used a 4-wire milliohm capable meter, connected the 2 source wires each on oposite sides of the two strip lines and measured the resistance between 2 parallel points with the 2 sense lines. Think of a H. In the middle is the lowest resistance. So i found the position with the lowest resistance.And on further inspection i found a needle forest of ultra thin tin whiskers of about 2mm length (1/10 inch). After removing them with a rubber the instrument went to life.Reason for tin whiskers are many. In this case it seems copper lines with tin plating and no other coating between.

author: Gyro
author_rank: Super Contributor
timestamp: August 24, 2022, 04:15:11 pm
content: That looks unpleasant, especially for a Fluke. I wonder if it has been stored in cold damp conditions.You could either try a decent conformal coating, not guaranteed to prevent regrowth indefinitely, or, more tedious unless localised, tin the affected tracks using Tin/Lead solder. The Lead should suppress further dendrite growth.

author: RolandK
author_rank: Regular Contributor
timestamp: August 24, 2022, 06:36:28 pm
content: I just used a rubber and blew them away. All the tin wiskers were in one location, where no parts were mounted, nowhere else. Indeed the area may have been the coolest location in the instrument. But i could not see under the switches and the 50 years history are unknown. Hope it will last the next 50 years.
Fluke 83/85 and 87 lcd displays are not interchangeable - Page 1
Forum section: electronics / repair

author: ogdento
author_rank: Regular Contributor
timestamp: January 02, 2020, 04:14:05 am
content: TLDR: an 83/85 (v1 or v3) display will NOT work in an 87, and an 87 (v1 or v3) display will NOT work on an 83/85.I was testing a "broken" fluke 87 v1 meter and discovered that it was actually fine, but just had an 83/85 v1 lcd in it...I always thought the 80 series displays were interchangeable (with the exception of the 88 and 5/V series)... I recall various forum posts suggesting that while the 83/85 display didn't have a "duty" indicator (which isn't used anyway) and had more bar graph segments, it would - or should - work in an 87. However, it absolutely will not!The displays look almost the same:Even though the 83/85 and 87 displays look nearly identical, Fluke used a completely different column and segment layout on the two displays... which is why the display was garbled when I turned my 87 to Ohms, using an 83/85 lcd. It should show "Auto", "0.L", "M" ohms, "40" range, and illuminate entire bar graph... but instead shows this:A look at the service manual shows S0-S31 (and H1-4) control entirely different segments on the two LCDs. About the only common ones are "AC", "DC" and a few bar graph bits. I've attached snips of both:The 83/85 v1 display (fluke # 782763, manuf # LS393C):The 87 v1 display (fluke # 832188, manuf # LS394E):So for example, "Auto" is controlled by S17 on the 87, but it's S16 on the 83/85 (and the columns H1-4 are flipped too)... so with an 83/85 lcd in an 87, we get the right bar graph arrow instead of Auto.An 87 display is the only LCD that will work in an 87, and an 83/85 display is the only LCD that will work in an 83/85. In both cases, a v1 or v3 LCD can be used on a v1 or v3 meter of the same number (83/85 or 87)... so in that respect the ONLY interchangeability is with the revisions.

author: mzacharias
author_rank: Frequent Contributor
timestamp: January 02, 2020, 12:51:47 pm
content: I used an 83III LCD for an 83 Series 1. Works fine and has larger digits.It did not work in an 87 but I suspect an 87III LCD would be backwards compatible with an original 87.

author: Mortymore
author_rank: Frequent Contributor
timestamp: January 02, 2020, 01:50:50 pm
content: Quote from: mzacharias on January 02, 2020, 12:51:47 pmYes it is.I have one 83 with the LCD from a 83III and one 87 with the LCD from a 87III

author: ogdento
author_rank: Regular Contributor
timestamp: January 02, 2020, 04:06:46 pm
content: Yep, Mortymore and Mzacharias... that's absolutely what I was saying... the ONLY ones that work are the 1 or 3 version in the same model number, so an 87 3 display works with an 87 1 and vice versa (same with an 83/85). I too have an 87 1 with an 87 3 display, and the 83/85 1 lcd works fine in my 83-3
fluke 83v backlight - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: September 02, 2021, 09:47:13 pm
content: Hi all,i have a fluke 83v,it works great except recently i needed to turn on the lcd backlight as i was in poor lighting conditions,it beeps when i press the backlight button but thats it,the backlight doesent actualy turn on,i havent pulled it apart yet as been too busy,as i dont have any schematics etc i thought i would ask here,just wondered if this was a common/ known faul?,cheers in advance.

author: mzacharias
author_rank: Frequent Contributor
timestamp: September 03, 2021, 02:32:44 pm
content: I would suggest cleaning and re-seating the connection to the backlight.This is a fairly common symptom.

author: m3vuv
author_rank: Super Contributor
timestamp: September 04, 2021, 07:56:28 pm
content: found the issue,the backlight is an smd led,it has suffered water damage along with a couple of tracks,one end of the led has the connection eaten away,i have repaired the tracks but need to replace the led,its as near as i can tell 3mm long and 2mm wide,would anyone know the number of the part as in 0605 etc,cheers Paul.

author: m3vuv
author_rank: Super Contributor
timestamp: September 04, 2021, 08:58:27 pm
content: well i just ordered some 5730 smd leds,should be good i imagine.
Fluke 845 AB Repair - Page 1
Forum section: electronics / repair

author: TheDefpom
author_rank: Frequent Contributor
timestamp: September 01, 2023, 01:28:37 am
content: Part 1:Part 2:Coming soon...

author: Dr. Frank
author_rank: Super Contributor
timestamp: September 01, 2023, 09:21:48 pm
content: I'm already very curious since months.Hopefully, the oscillator transistors have survived w/o battery pack.Frank

author: TheDefpom
author_rank: Frequent Contributor
timestamp: September 01, 2023, 09:40:32 pm
content: Yes it all still works fine, Part 2 includes me replacing the missing battery pack.

author: srb1954
author_rank: Super Contributor
timestamp: September 02, 2023, 03:48:27 am
content: Quote from: Dr. Frank on September 01, 2023, 09:21:48 pmFor the 845AB battery version they seem to be relying on the battery pack to clamp the PSU voltage to the circuitry to safe levels. Without the battery pack that supply voltage could rise to higher than desirable levels.For the 845A version, without the battery, there is a 10V Zener across the supply to clamp the voltage to safe levels. It might be advisable to add that Zener into circuit.

author: srb1954
author_rank: Super Contributor
timestamp: September 02, 2023, 03:51:57 am
content: You don't get an earth connection to the internal metal case as it is isolated from the main case and is connected to the guard terminal.The 2 transistors on the extreme right side of the circuit diagram make up a synchronous rectifier to provide a transformer isolated DC O/P for an external recorder.

author: Dr. Frank
author_rank: Super Contributor
timestamp: September 03, 2023, 11:35:16 am
content: Quote from: srb1954 on September 02, 2023, 03:48:27 amThe battery pack acts like a zener diode, that's what I already have written @ YT on the first video, as well that w/o battery pack the oscillator transistors could be damaged by overvoltage.. the output voltage of the transformer is quite high.It would definitely be a big mistake to add the 10V zener diode, CR 207 as indicated in the AB manual, as this would completely disturb the charging of the battery.In my 845AR, I have replaced this crude zener stabilization (R202, CR207) by a proper LM317 stabilizer circuit.Frank
Fluke 8505A doing ohms - Page 1
Forum section: electronics / repair

author: m k
author_rank: Super Contributor
timestamp: June 18, 2022, 03:10:50 pm
content: It's a bit off.(13R6)Voltage change is not noise.Reboot(120K)Both machines have isolators but only older version is showing it.Pressing Filter.(Filter)Both have mode F.Only current mode F is ticking differently.Bypass mode.(Store 1 Filter)Steady lower current.Very slow combined mode F2.(Store 2 Filter)Only current mode F2 is again ticking differently.Mode F3.(Store 3 Filter)Back to mode F.(Store Filter)Current filter led fails.Combined mode F but no led.If current is not mode F its value is ticking differently.Upper machine has Active Filter changed.Some combinations may have had differences but generally there are no effect.E,didn't understand the ending.E2,Dang, can't stand that ütub, it shrinked them files even more, so they continue here then.

author: m k
author_rank: Super Contributor
timestamp: June 19, 2022, 06:23:53 pm
content: So how was it exactly.Can't say how it is with currents but voltages were filter steady.Earlier differences when upper and lower machine had different filters are verified, current reading is ticking differently but reason is not known yet.Ohms then are clearly switching between filter and bypass.v502 ohms filters tickingF = 2x(filtered, bypass) then 2x(+V filtered, bypass) and repeat.F0 = 7x(filtered, bypass) then 7x(+V filtered, bypass) and repeat.F1 = 3x(2x(+V bypass, bypass), 4xbypass) then 3x(3x(+V bypass, bypass), 6xbypass) and repeat.F2 = FF3 = F04x and 6x can be more or less.7x +V can be repeated less than 10 times and then maybe one or two 6x.

author: m k
author_rank: Super Contributor
timestamp: June 20, 2022, 05:14:21 pm
content: All variations are not checked but all software versions(2,3,4,6) seems to be the same.Currents are also filter steady.Current changes when measuring other machine Ohmsv504 filterF = F0F0 blink fast if Ohms FF0 blink slow if Ohms F0F1 steadyF2 slow tick, fast change if Ohms FF2 slow tick, slow change if Ohms F0F3 semi tick, fast change if Ohms FF3 F & F0 blink fast if Ohms F0When measuring HP ohms there are no current changes.This is also the only Ohms Controller available, same with Current Shunts, so no idea what happens when it is repaired.And matching sample led and those current and voltage readings is a bit difficult but link there obviously is.To see those Active filter selections I did a sniffer, small clips, LEDs and LS244.TTL floating as high will ease testing it, just connect power and all LEDs should lit.
Fluke 8505A Extender Board - Page 1
Forum section: electronics / repair

author: mdubinko
author_rank: Contributor
timestamp: October 19, 2021, 09:07:04 pm
content: Hello all,I've perused several great threads here and webward, on Fluke 8505a and 8506a repairs. One I particularly enjoyed was the thorough write-up on xDevs.https://xdevs.com/article/f8505a/The photos there show an author-produced extender board to allow taking measurements on live modules, in-circuit. Does anyone know if this board is available for purchase anywhere? Or failing that, are there gerbers anywhere? (Or failing THAT, accurate measurements?)I haven't been able to locate the author of that article to ask them directly. Anyone have any leads?Thanks & 73,-m

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 20, 2021, 11:44:58 am
content: https://www.eevblog.com/forum/profile/?u=26015

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 20, 2021, 11:45:47 am
content: This is a link to the profile of the author of xdevs.com

author: TiN
author_rank: Super Contributor
timestamp: October 20, 2021, 08:17:53 pm
content: Razvan is present inxDevs IRC chat, depends on time zone.
Fluke 8520A  Err23 HDWR Time error, incorrect response from A/D Converter  - Page 1
Forum section: electronics / repair

author: mario_nks
author_rank: Contributor
timestamp: May 11, 2023, 05:38:54 am
content: Hello,Unfortunately I have a non-functioning Fluke 8520A.I have already found an error:Err17 HDWR_ | Sync failure between the microprocessor and the A/D converterHere it was IM6402-1IPL defective.BUT:But now I still have the following errors:Err23 HDWR Time error, incorrect response from A/D ConverterI just can't get any further here.Can someone help me here?Kind regardsMarkus

author: mario_nks
author_rank: Contributor
timestamp: May 11, 2023, 07:40:44 am
content: Can someone explan me where the " guard crossing cable" is located ?
Fluke 8600A Display Blanks off - Page 1
Forum section: electronics / repair

author: OldGrayOwl
author_rank: Newbie
timestamp: April 04, 2025, 09:11:11 pm
content: I have a Fluke 8600A (non-battery version), and the display blanks off after a few minutes to a few hours operation, but returns after a smack to the case.I have looked for and re-soldered some funky looking solder connections, but it still does it. Any idea as where to look for issues?Thanks

author: wn1fju
author_rank: Frequent Contributor
timestamp: April 04, 2025, 11:08:21 pm
content: Smacking the case isn't going to tell you much other than you have an intermittent connection somewhere. You need to flex the cables/connectors, sharply tap on the components (with insulated tool), press on areas of the board, reseat any socketed ICs and spray some cleaner into the pushbutton switches. See if you can either induce the faulty display or have it recover from the fault. You might also check the power supply voltages if and when the display blanks. The service manual also has a few checks of voltages and signals driving the display board. If you have access to a heat gun and some cold spray, you might try that too.You will eventually find the problem, but it may take a little time.

author: Gertjan
author_rank: Frequent Contributor
timestamp: April 07, 2025, 06:33:49 am
content: Hi OldGrayOwl,The Fluke 8600A is still a meter worth to repair. Easy to use, the specs are fine for most use cases, and compared to contemporary meters it is conveniently small.I had a few repairs with bad solder joints between the mainboard and the display flex PCB. So check those. Re-flow with fresh solder when in doubt.Also some brands of the used IC sockets are notoriously for bad contacts. Wiggling or reseating the IC will show the problem. The only real solution is replacing the offending socket.regards & good luck, Gertjan.

author: valleyken
author_rank: Contributor
timestamp: April 07, 2025, 12:55:06 pm
content: - I found this video about that Fluke multimeter, also with display issues. Thought it might be helpful. You'll also see other suggested videos about people repairing the same multimeter, so at least there should be some tips in there about all the things to check.Valleyken
Fluke 863 erratic incorrect readings (DT,OHMS,ACV,DCV)  mA is black screen - Page 1
Forum section: electronics / repair

author: Diesel11
author_rank: Newbie
timestamp: June 28, 2022, 06:33:24 pm
content: I have cleaned contacts ptf black stuff and finally got everything working. Until I noticed most functions show on display but erratic readings on every selection of the knob
Fluke 865 Graphical Digital Multimeter > needs Calibration - Page 1
Forum section: electronics / repair

author: sampler1
author_rank: Regular Contributor
timestamp: December 12, 2023, 02:05:59 am
content: Hi All,I have never had any of my gear calibrated so I am comming at you as an ignorant son of a B. hahaI have a Fluke 865 Graphical Digital Multimeter that works perfectly but the DC Volts has slowly gone out of calibration.( roughly +- 1/2 volt) Does anyone have an idea where I could get it calibrated in Canada? Preferably Quebec? Also what would your guess be on the cost?I looked in the service manual and I just don't have the calibration equipment to do the job. It does look quite simple.Cheers and Happy Holidays.

author: boggis the cat
author_rank: Regular Contributor
timestamp: December 12, 2023, 02:28:16 am
content: Check here for accredited labs:https://nrc.canada.ca/en/certifications-evaluations-standards/calibration-laboratory-assessment-service/directory-accredited-calibration-laboratories?f%5B0%5D=field_of_calibration%3A30075There are a fair number in Quebec. Note that commercial work isn't usually cheap, but possibly if they are too pricey they can suggest alternatives.

author: bdunham7
author_rank: Super Contributor
timestamp: December 12, 2023, 04:41:04 am
content: 0.5 volt on which scale(s)? Unless that is on the 300V or 1000V range, that is a significant error and I'd be dubious that calibration alone would be the fix.

author: Swake
author_rank: Frequent Contributor
timestamp: December 12, 2023, 06:41:11 am
content: I second that message. If it is half a volt in any lower range it is not a calibration issue unless this has been tampered with. What ranges exactly have that issue?
FLUKE 867 Graphic Multimeter Calibration  - Page 1
Forum section: electronics / repair

author: Crambone
author_rank: Frequent Contributor
timestamp: April 08, 2020, 08:41:04 pm
content: My Fluke 867 Graphic Multimeter is showing false readings when checking capacitors. In the pf range it is off on average around 220pf on the high side. I have double checked and rechecked several capacitors. In the k reading it is dead on. I’m guessing it needs to be calibrated. Everything else on the meter is working perfectly. Is this an adjustment I can make?If not I’m located in NJ and would like recommendations on were to bring/send it?

author: Tomlef
author_rank: Newbie
timestamp: April 19, 2020, 01:24:40 pm
content: Hi.I used to have that unit and calibrated before someone stole it.It was very easy to calibrate it, you only need some good voltage references and maybe some other inputs like resistor, amp etc. I can't remember.There is a service manual which is very good written and explain everything. There is a service menu -I can't remember how you enter in it- and you just follow the on screen prompts, like apply 5.000 DCV, the screen reads 5.018 V, press that key, you wait and correct it 5.000V !! That simple.I've send it to a friend you had access to some good and accurate (calibrated) bench testers/generators/resistor & capacitor boxes, and calibrated. He said it was the most easy calibration ever did.I will try to find the manual, I have to dig in some old HDDs, try to google FLUKE 867 Service Manual.Just be sure to use calibrated values otherwise you'll set wrong your meter.
Fluke 867 no power/lcd (Repaired) - Page 1
Forum section: electronics / repair

author: longboard1210
author_rank: Contributor
timestamp: July 04, 2020, 08:45:30 am
content: Morning guysFluke 867 with no power or no lcd displaythe unit appears to be doing something as it has about 0.15a draw from my power supply when turned onHowever my 3.3v rail is at 4.2v for some reason VCCI have ot got stuck into it yet but anybody had ant experiance with the units ?

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2020, 11:44:07 am
content: Following. (I recently found an 867 at work in storage, and it's also not working. It'll power on in some ranges, but is often on the wrong range, and the display has glitches. I cleaned the rotary switch and it made no difference, so I think it's a logic issue. Didn't have a chance to check voltages or anything, and I've put it back in storage for now.)

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 05, 2020, 08:55:11 am
content: @Tooki: I wouldn't be surprised if yours was a case of battery contamination behind the CPU.

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 05, 2020, 09:03:22 am
content: Related topics...https://www.eevblog.com/forum/testgear/please-help-for-strange-problem-with-fluke-867b-dc-measurement/https://www.eevblog.com/forum/repair/after-three-evenings-with-a-fluke-867b/

author: longboard1210
author_rank: Contributor
timestamp: July 08, 2020, 03:06:28 pm
content: Hi thanks but these did not have the same issueLong story short it helps to read the block diagrams and i mean read and understand them you end up chasing your tail if you dont a quck scan on a screen is not the sameIts been a first for me usually i do work on the fly witout schematics and gut feeling always plays a part in diagnosisWhen i checked the board over i felt that the voltages were just to high on the board and wouldnt you know it the 2.5v voltage referance that is on the board was outputting 5v not the 2.5v that the scematicsand the exellent fluke manual said it should beso i replaced the voltage reg and she sprang to life done a few bits of testing and it seems to be pretty good well fine for what i need anywaynext upgrade i will see if i can throw a decent backlight in there
Fluke 867B (logic and component test not working) - Page 1
Forum section: electronics / repair

author: eduaqa
author_rank: Contributor
timestamp: February 07, 2025, 11:56:05 pm
content: On my fluke 867B the logic and component test is not working, the display comes on but not shows.While looking on the Service Manual (free download on fluke site), it explain that the selection switch use a resistor divider to set the function (see attached this portion)I noted the voltage going to the resistors networkI noticed that the rotary switch itself is adding around 2.1k resistance on the divider, what could explain why the other function works because 2.1k additional for more high value from other positions don't influence much on the setting, however:LOGIC is the first position, so it just ground the 5v (after passing to the resistor 49.9k), which should generated around 0V as resultCOMPONENT TEST, is a 4.99k resistor, so when divide with 49.9k should generated 0.47vhowever in this current scenario, the switch is adding 2.1k as result we have for logic 0.2v and for component test 0.63v and then the main processor don't understand what is the switch position and shows nothingTo test my theory, a add in parallel to the switch the 2 resistor (100ohms (to simulate ground) for logic and 18000ohm (to simulate 4.99k) for component test) and both WORKEDNow, any idea if it's normal this 2.1k resistance on the switch itself and can be another problem? Or, any idea how to fixed the switch? the part of the PCB where the blades move is black like those similar to potentiometer.
Fluke 867B Display - Page 1
Forum section: electronics / repair

author: abrasumente
author_rank: Contributor
timestamp: April 16, 2025, 01:39:50 am
content: Back again with another project.I bought a used Fluke 867B from the bay with a bad display. Bought a NOS display and dropped it in. Works great, except there is a vertical line present. It doesn't (to me) look like damage because it varies in intensity depending on what's actually displaying. If it was damage, wouldn't it be fairly consistent? It doesn't seem time dependent either (like something getting too warm)- the component test was the last picture I took, at which point the meter had been on for 30 minutes straight.

author: Paceguy
author_rank: Regular Contributor
timestamp: April 16, 2025, 10:41:21 am
content: I never took my 867B apart. I would start by checking all the connections between the display and circuit board. It could be something with those ribbon cables on the display board.

author: abrasumente
author_rank: Contributor
timestamp: April 25, 2025, 11:01:18 pm
content: Ribbon cable is seated firmly and does not show any signs of damage. I suppose it's possible this display is "new" but got whacked at some point in the last 30 years. The display that came in the meter originally had a ton of horizontal lines, but none vertically.I may try to find another display and see if it has the same problem. At that point though I'll be keeping it because I'll never be able to recoup what I've put into it. A good excuse to tell the wife

author: Ugur
author_rank: Regular Contributor
timestamp: April 28, 2025, 11:28:05 am
content: If it does not affect your usage, do not touch it. Otherwise, the screen may become worse.
Fluke 867B issue - Page 1
Forum section: electronics / repair

author: Crambone
author_rank: Frequent Contributor
timestamp: May 08, 2020, 05:28:25 pm
content: Well I did the unmentionable and hit 2000V with my meter and heard a pop and then no readings on any function. The unit powers on and the screen displays the modes I’m on eg. VAc, VDc, Capacitor, Diode..... but won’t take a reading. I opened up and found R99 popped off the board! 😬I checked the resistor and it tested good on another meter but tossed in trash and installed a new one. Didn’t see any evidence of anything visually but once powered on with new resistor still the same.Any suggestions were to start looking. The big issue is I don’t have a diode or capacitor tester now!

author: Wytnucls
author_rank: Super Contributor
timestamp: May 08, 2020, 07:45:50 pm
content: I would check the protection circuit:RT1 1.1KRV1 RV2 RV3R20 100K

author: Crambone
author_rank: Frequent Contributor
timestamp: May 08, 2020, 11:03:13 pm
content: Well when my NEW meter comes in :palm:I will check them. Thank you for your help!

author: shakalnokturn
author_rank: Super Contributor
timestamp: May 08, 2020, 11:12:29 pm
content: I've just received a 867B with battery corrosion and haven't been able to check it as working yet however I'd be really unlucky if it had been blasted with an over-voltage on top of that.If you've had no luck with the input protection and want a clue on the RIC2 pin 21 input:On mine with switch in off position and using diode test on another DMM reads 0.96V with common to 867B's input common and positive to S1-6, reversing polarity reads 1.47V.
Fluke 87 (87III) Diode Test Not Working - Page 1
Forum section: electronics / repair

author: pkomoro
author_rank: Newbie
timestamp: September 19, 2024, 04:15:48 am
content: I have an older Fluke 87III and the diode test is not working. I get no beep, no change on the display.If i short the leads, the display updates to 0V, but again, no beep.The speaker works and beeps on continuity tests, so it's definitely something specific to the diode test.Any suggestions?

author: coromonadalix
author_rank: Super Contributor
timestamp: September 19, 2024, 09:57:31 am
content: service manual w schematics83 85 87 1st series, it should be similarhttps://assets.fluke.com/manuals/83_85_87smeng0500.pdf
Fluke 87 1st gen. AC and DC Voltage not auto-ranging - Page 1
Forum section: electronics / repair

author: Gary IN
author_rank: Newbie
timestamp: November 15, 2024, 08:06:44 pm
content: I got this old Fluke 87 first gen. with the following problems & could use some brain power to fix it.VDC always displays minus 39V (pic). When I measure 30VDC it will add or subtract only 5V - depending on polarity.VAC first jumps up and down in the mV range, which seems to look ok, but shows 24.5 VAC when plugged in to 115 VAC outlet.Diode test shows max (no zero or anything else)._______________________________Strangely, everything else seems to work OK: mV DC. Ohms, continuity buzzer, Amps, mAmps and microAmps show accurate values.Both fuses were blown when I got it

author: Gary IN
author_rank: Newbie
timestamp: November 16, 2024, 02:52:49 pm
content: Any ideas?Schematic pages from the Service Manual attached.

author: dustooff
author_rank: Contributor
timestamp: November 18, 2024, 09:13:24 am
content: Hi,have you tried cleaning the rotary switches?

author: MathWizard
author_rank: Super Contributor
timestamp: November 18, 2024, 10:47:04 am
content: So it looks like ACV, DCV, DT and Capacitance use mostly the same RC networks and internal switches in the IC. So does capacitance also not work right ? You can check the RC parts around that IC. IDK about these meters, but I'm worried it's those switches inside the chip.

author: Gary IN
author_rank: Newbie
timestamp: November 18, 2024, 01:51:06 pm
content: Quote from: dustooff on November 18, 2024, 09:13:24 amI wiped that rotary switch and it is in perfect shape. The readings showing on the display are consistent.Thanks for the suggestion.

author: Gary IN
author_rank: Newbie
timestamp: November 18, 2024, 02:12:31 pm
content: Quote from: MathWizard on November 18, 2024, 10:47:04 amThank you for the suggestion!I quickly tested those RC parts before but will check them again later today. The capacitance meter did show some nF without anything connected to it. So,I think you are on the right track. With testing 1 to 4.7 μF it seemed ok-ish, maybe 20% off compared to my good Fluke 87V. But I will double check that again. I know that the 1st gen. 87 has v. limited capacitance test range.If the internal switches are fried, then I will just use this Fluke for μA/A, resistors and continuity buzzer.
Fluke 87, Dead, chirps sometimes - Page 1
Forum section: electronics / repair

author: iblackford
author_rank: Contributor
timestamp: January 09, 2022, 01:34:07 pm
content: Hi All,Apologies if this or a similar problem has been covered already in an existing thread. I have done some searching, and I haven't found this issue.Symptoms on my Fluke 87:-Unit is dead, no display, no beeping when trying to do a continuity test in the ohms position (yes, I tried pushing the speaker button to enable the beeping)-There is a slight "chirping" that I can hear when switching modes.-no backlightThings Tried/Measurements taken:-Resoldered the 9V battery connector as it looked suspect. No Improvement. Verified that 9V is present on the PCB-Checked VDD to U4, and it's present (~3.2V, relative to VSS)-Checked that the oscillator to U4 is runningQuestions/Further Actions:-U4 (main custom ASIC) seems suspect to me, given that it drives everything (backlight, speaker, display...) what other things can I try to rule out before assuming it is U4?-There is a "TEST" mode for U4 referenced in the service manual. Does anyone know how to initiate this mode?-Are there any options to purchase U4 (SPX-87) or similar equivalent IC?Thanks in advance, Ivan

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 10, 2022, 01:06:25 am
content: A couple of thoughts as you have already done most of the routine checks I would have recommended.I haven't been out looking for the schematic so some suggestions may not apply.Check current draw, some flukes have the buzzer driven by CMOS logic permanently supplied from battery. Sometimes the IC fails and drains the battery fast. I doubt it would give your symptoms but measuring current can still give you some clues on what's going on or not.Check / clean function switch contacts, some models use a carbon coating that wears away and causes trouble.If there's a SPI or I²C serial memory check bus activity.If all else fails try reflowing the TQFP's I've had more than one Fluke meter acting funny that behaved after resoldering.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 10, 2022, 10:03:27 am
content: have to play with the rotary dial on one of my 87 at the jobPlay bonkers, beep for nothing, display stuck etc ... have to rotate it as few times and get it to work, yeah i'm lazy to open it and clean and lube the dial contacts, maybe they are used up to a point, theses meters are intensively used ...
Fluke 87 III - brittle plastic, broken screw posts. - Page 1
Forum section: electronics / repair

author: aargee
author_rank: Frequent Contributor
timestamp: December 16, 2021, 03:15:45 am
content: Hello all,I have a Fluke 87 mark III, its lower screw posts that hold the two halves of the meter together have snapped.One was broken at first, with the remnants rattling around inside. On inspection to see what was rattling the other one broke when re-assembling.It appears that the plastic has become brittle and easily crumbles.This may have been affected by fumes from a previously leaking 9V battery? The plastic of the posts and the case in the immediate battery vicinity seem to be brittle.Without replacing the front shell, I'm looking for options. Top of the list is 3D printing an ABS pillar(s) and gluing them in as replacements - I'm just concerned about the ability of the bonding to hold. Does anyone have any other suggestions?

author: james_s
author_rank: Super Contributor
timestamp: December 16, 2021, 03:52:32 am
content: I've never seen a battery cause that but maybe it's possible? I've heard that some disinfectants can cause the plastic of medical equipment to become brittle. I have a Tek TDS3000 scope that the entire housing and knobs all turned brittle and started crumbling to dust.The plastic is PC-ABS, probably the same stuff the Fluke meter is made of since it's very durable normally. Maybe there's a plastic engineer around here who would have some insight.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 16, 2021, 03:38:59 pm
content: when you have the broken studs, try to glue them / realigne themI used a mix of superglue and baking soda for one of my 189, and slowly rehtreaded the screw in it, Fluke have special threadsBe careful, normally the super glue will tack really fastStill hold fine after a few years

author: MarkL
author_rank: Unknown
timestamp: December 16, 2021, 06:43:36 pm
content: I've used this stuff to brace or rebuild broken plastic posts:https://www.plast-aid.com/

author: andy2000
author_rank: Frequent Contributor
timestamp: December 16, 2021, 06:52:22 pm
content: I'm not sure what causes it, but certain batches of ABS plastic become extremely brittle. I know it's not caused by the environment because it often only affects one piece of a device. I'm not aware of any way to fix it other than replacing the defective parts.
Fluke 87 III continuous flashing ALL display segments  - Page 1
Forum section: electronics / repair

author: raceone2
author_rank: Newbie
timestamp: January 10, 2022, 03:59:05 pm
content: What causes my Fluke 87 III to continuously flash ALL display segments when turned ON to any rotary position? (ON for ~ 2 sec, OFF for ~ 0.5 sec, repeats).

author: raceone2
author_rank: Newbie
timestamp: January 10, 2022, 07:34:10 pm
content: Hey, I found out the battery was a poor excuse for a 9V so I replaced with a Duracel and corrected the problem. It works fine now!

author: tooki
author_rank: Super Contributor
timestamp: January 15, 2022, 11:50:14 am
content: Just check the Duracell every few months for leakage, since Duracell is just THE worst in that regard.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: January 16, 2022, 01:25:47 pm
content: Lots of my Durahell batteries have leaked. But not the 9 V ones.I am still watching them none the less.

author: SeanB
author_rank: Super Contributor
timestamp: January 16, 2022, 04:37:57 pm
content: The Durahells leak still, just they tend to dump that lovely caustic product into the terminal area after a few weeks, and then it migrates up into the battery holder contacts, and, if it is the clip type, it corrodes up the wires, or if it is a plate type it corrodes them nicely, and then migrates to the board.Never had a failed 9V battery, other than the mass plate zinc oxide type, where at least one of the internal AAAA cells had not leaked out somewhat when the battery was at it's end of life voltage. The mass plate works well for that because they are wax impregnated, so contain the goo pretty well. If the corrosion has gone into the holder you need to replace with a new one, complete with wires, because they will be rotted out inside the insulation.
Fluke 87 switches itself on sometimes - Page 1
Forum section: electronics / repair

author: Oleander
author_rank: Contributor
timestamp: October 16, 2020, 02:38:18 pm
content: Hi folks,My old Fluke 87 turns itself on sometimes, even when main rotary switch is in off position.Is anybody here with the same phenomena (and solution) ?

author: rvalente
author_rank: Frequent Contributor
timestamp: October 17, 2020, 12:29:49 am
content: Never happened to me, I only own one 87V, dunno which board revision it is (probably there are a few), have you checked the switch contacts? Are they clean?

author: rcjoy
author_rank: Regular Contributor
timestamp: October 17, 2020, 01:43:31 am
content: Yes, it happens to my original model 87. It will also flicker on and off. I took it apart but it was not obvious why it would do it.Forcing the dial against the "off" stop will cause it to turn on, so I back it off a bit to avoid that.

author: Oleander
author_rank: Contributor
timestamp: October 17, 2020, 12:47:58 pm
content: Quote from: rcjoy on October 17, 2020, 01:43:31 amThat is exactly what happens to my original model 87. Now I'll clean the dial contacts more deeply, let us see the result.Moving the dial near/around the "off"position is not a real solution.

author: tooki
author_rank: Super Contributor
timestamp: October 17, 2020, 03:50:35 pm
content: Following. I have an old 87 at work that’s doing this. Haven’t gotten around to trying to fix it yet.

author: mzacharias
author_rank: Frequent Contributor
timestamp: October 17, 2020, 08:21:53 pm
content: OK, all. This is a common problem.Just clean the main function switch and the encoder switch on the other side of the board.Don't just spray cleaner willy nilly. A drop here and there at the function switch contacts, exercise it through it's settings, and a dry swab on the circuit board portion of the encoder switch to clear any particle residue.End of problem.

author: Oleander
author_rank: Contributor
timestamp: October 18, 2020, 11:39:34 am
content: I did exactly as promised (and as above), the problem now seems to be gone
FLUKE 87III MULTIMETER REPAIR - Page 1
Forum section: electronics / repair

author: pierrechan68
author_rank: Newbie
timestamp: February 22, 2022, 05:28:14 am
content: I have a fluke III multimeter, as 9V battery no power, i use a power adapter to provide power, unfortunately, i make wrong polarity, + and - are change with wrong polarity. the meter light up with beep sound continously and the reading are show on the screen. but the reqading are not accuate, which part sould i change to repair, thank you.

author: shakalnokturn
author_rank: Super Contributor
timestamp: February 22, 2022, 09:01:26 pm
content: The Fluke worshipers are going to be frowning at you!Is it an impression or has the small tantalum capacitor near PCB edge on underside turned from yellow to brown?

author: strawberry
author_rank: Super Contributor
timestamp: February 22, 2022, 09:19:54 pm
content: fusemain controller could have separate 3.3V or 5V regulatedIf MCU operates normal then some op amps maybe

author: pierrechan68
author_rank: Newbie
timestamp: February 23, 2022, 09:50:04 am
content: I FOUND 2 transistor maybe burn. THE CODE is P99 and JC2 on the transistor. what is these true value? thank you.

author: floobydust
author_rank: Super Contributor
timestamp: February 23, 2022, 08:16:16 pm
content: NEVERrun a handheld multimeter from a bench power supply or wall wart. Why are people so cheap.Because input com(-) is not DC power(-) and any short or voltage forced between them will blow up the main multimeter IC or diode CR5. Check CR5.For the Fluke 87III, I'm not sure if I have the specific service manual for it. edit: 87IV,V I think:It has three voltage regulators (power rails) U10 making 5V, U6 making 3.3V and U8 making 2.5V. BUT to get +/-2.5VDC and +0.8VDC, they use a floating common to the +2.5V regulator as analog common. Yes it's confusing.Running the meter from a 9V battery, check the three rails with another multimeter its (-) to the 9V(-).Should measure around 9V at TP16 U10 input, 5V at TP17, 3.3V at U6 output or C13, 2.5V at UI8 output or C16.added block diagram and typo up top? VDD should be +3.0V not -3.0V I think.I would think the main multimeter IC is blown, it usually gets damaged because it's only a 5V part. Or dual diode CR5, or Q8 have failed but the power would not switch off.Power SwitchQ3 NPN BJT, MMBT3904, Fluke 742676Q8 N-ch MOSFET, 2N7002, Fluke 927538Q10 P-ch JFET, SST175/J175, Fluke 832477. SOT-23 DGS, SMD marking code "S5" or "P05".CR5 dual diode, BAV99, Fluke 742320Input Protection clampQ13,Q14 NPN BJT, MMBT6429, Fluke 912469, SMD marking "1KM" or "M1L".Q1,Q2,Q6 NPN BJT, MPS6560 but also given as SMBT1388LT1, hand selected for low IEBO, Fluke 821637Backlight etc.Q5,Q11 PNP BJT, MMBT3906, Fluke 742684
Fluke 87IV has high error with 50mV and 500ohm Ranges - Page 1
Forum section: electronics / repair

author: rniu
author_rank: Newbie
timestamp: July 26, 2022, 01:14:30 pm
content: I got one used 87-IV DMM. After calibrated it with Fluke 5500A, I found there's a couple of mV error on DCV range even if I shorted the inputs. Then I redo the calibration, the 50mV range looks no good as I see the last 2 and even 3 digts changes a lot. Also notied the ohm range always have 4-6 ohm reading if I short the input terminals. If I short the terminals, the 50mV range also shows about 0.3mV offset. I have tried soaking the board into alcohol for 2 days and bake one night with 70C. It didn't work.Appreciated if any inputs.Thanks!

author: rniu
author_rank: Newbie
timestamp: July 29, 2022, 02:46:29 am
content: To describe more details: On mV range, the shorted results is 0.3xx mV. Then switch to Ohms range, the shorted reading is 3.xx ohms. If switch to other Ohms range manually, every range will show 003x offset even in Kohms, Mohms ranges. It looks like a consistent offset always. I have put the board into alcohol over 24 hours for twice. Didn't help.

author: Ugur
author_rank: Regular Contributor
timestamp: August 03, 2022, 02:04:37 pm
content: If you are sure that the internal resistance of the shorted test lead is low, you can try to do the adjustment calibration.

author: srmahaffy
author_rank: Contributor
timestamp: August 08, 2022, 04:59:17 am
content: Hi, make sure the “com” port and the “V” ports are clean, and that the test leads are seated well. You can also check the continuity between each port, and its solder pads, to make sure you have good continuity. If not, try cleaning, and reflowing the solder pads.Use Isopropyl alcohol 70% or 91% to clean the ports and solder residue on the PCB, (if you do any soldering). Also, are you sure your test leads are good? Let us know how things are going.

author: srmahaffy
author_rank: Contributor
timestamp: August 08, 2022, 05:02:28 am
content: Sorry, I overlooked your information on your use of Isopropyl alcohol and baking. Check the continuity of each of the meters ports to the PCB.