hybridfree/eevblog-posts huggingface dataset:
FLUKE 754 does not generate current nor does it measure - Page 1
Forum section: electronics / repair

author: EDER
author_rank: Contributor
timestamp: June 26, 2020, 04:17:46 pm
content: Hello friends, I hope you can help me with your comments, I have a fluke 754 that does not measure current nor does it generate current, I replaced some components that were in short circuit such as the Q26, CR614, CR615, Q612, Q622, Q610, Q629 and R613 ( Open), now the equipment generates half of the value displayed on the screen. Can someone suggest any solution please? or if someone has the diagram or user manual I would really appreciate it.
Fluke 760A Meter Calibrator Repair  - Page 1
Forum section: electronics / repair

author: psykok
author_rank: Frequent Contributor
timestamp: February 15, 2021, 04:26:51 pm
content: Hi,Today I received my new lab encoreThe package was well done and pain to openOn the device in the workshop, I could realise how big it is:Cosmetic condition is not great but apart from missing screws and on missing button, it looks ok to me.

author: psykok
author_rank: Frequent Contributor
timestamp: February 15, 2021, 04:31:46 pm
content: The next challenge would be to find an adequate power cord

author: capt bullshot
author_rank: Super Contributor
timestamp: February 16, 2021, 09:09:23 am
content: Nice haulLooking forward to see more repair / teardown.

author: psykok
author_rank: Frequent Contributor
timestamp: February 16, 2021, 12:41:03 pm
content: Let's go for the teardown.The outside condition is not very good but inside everything looks good and almost clean (surprisely no dust)First the upper part of the instrumentA look under the protection coverCalibration boardThe null detector boardAC converter15v psu, assembly date is apparently in 75 ... was not even born

author: psykok
author_rank: Frequent Contributor
timestamp: February 16, 2021, 01:02:20 pm
content: If the two transformers are huge, the caps too

author: coromonadalix
author_rank: Super Contributor
timestamp: February 16, 2021, 03:30:20 pm
content: be careful the clear tubings on the pcb's hide / protect wire wounded precision resistorsseems heavy as a tank, sadly it seems to have been shaken a bit on the rear panel ??

author: psykok
author_rank: Frequent Contributor
timestamp: February 18, 2021, 06:50:58 am
content: Quote from: coromonadalix on February 16, 2021, 03:30:20 pmIndeed heavy as a tank but not armored like one.The case is made of thin aluminium panels.Fortunately this materiel is easy to bend and I was able to fix the back panel.I Also replaced the power connector with a more traditional one. This modification is completely reversible because the new connector is just fitting in the mounting holes of the previous one.One the back panel in place, it doesn’t look too bad, maybe just missing a new paint.Next job is fixing the wiring issues on the front command.
Fluke 77 (Series 1?) needs new rotary dial - Page 1
Forum section: electronics / repair

author: hypercoffeedude
author_rank: Newbie
timestamp: December 30, 2021, 03:34:52 am
content: Hello everyone, I managed to get ahold of an older Fluke 77 multimeter from an estate sale for $10. It turned on and worked, but when I moved the knob back and forth a few times the plastic portion of the rotary switch fell apart (likely due to old age). I need help locating a replacement rotary switch. I can provide photos of my unit if that would be helpful. However, for now I will just include a photo of a similar unit I found here which has a view of the same rotary switch in working condition.Fluke 77 MultimeterJohn Fluke MFG. Co. INC.Everett, WashingtonMade in USA Patents PendingSerial No: 40531228

author: bdunham7
author_rank: Super Contributor
timestamp: December 30, 2021, 04:10:45 am
content: You need Fluke p/n 642918. You aren't likely to find one very easily, but at least you start with a part number. You are more likely to find a parts unit than to luck into a new switch. Any 73/75/77 original series meter has that switch, but other 20-series models might as well.

author: El Rubio
author_rank: Regular Contributor
timestamp: February 22, 2022, 06:03:04 pm
content: Are you still looking for the dial? I have a broken 77 ( series ii, i think), but the dial is in good shape.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 23, 2022, 01:03:23 pm
content: have 3D printing creating one

author: Shock
author_rank: Super Contributor
timestamp: February 23, 2022, 04:09:08 pm
content: Hope these all don't fail. :/

author: mqsaharan
author_rank: Regular Contributor
timestamp: February 24, 2022, 05:39:24 am
content: Quote from: El Rubio on February 22, 2022, 06:03:04 pmHi El Rubio,My Fluke 77 (Series I) dial is also worn out. It doesn't even click in place anymore. So, I would like to buy it from you. Would you like me to send you a PM?

author: enrlaz
author_rank: Newbie
timestamp: March 25, 2023, 06:42:08 pm
content: Hii have the same problem with the rotary switch p/n 642918 like hypercoffeedude.I need used one cause fluke do not have any part number since 2007.This multimeter has a sentimental value for me.How someone solved?ThanksEnrico - Pisa - ITALY

author: Shock
author_rank: Super Contributor
timestamp: March 26, 2023, 06:26:50 am
content: Determine if you have series I or II and check from the manual if the Fluke 77 and 75 has the same switch or parts as it may be less expensive to source. Here is a couple of possibilities but check first.https://www.ebay.com/itm/134505634489https://www.ebay.com/itm/256018754951
FLUKE 77-3 YELLOW - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: May 12, 2022, 04:59:13 pm
content: Goodnight all! I am looking for an integrated circuit on a FLUKE 77-3 (yellow); here is its reference: FLUKE 603669.... Anyone have it (even in wreckage).... Thank you very much!

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2022, 06:18:20 pm
content: The odds of them actually having it are probably not good, but at least this outfit is listing it.https://www.radwell.com/en-US/Buy/FLUKE/FLUKE/603669/Otherwise, a smashed unit is about your only hope.
Fluke 75 measurement problem - Page 1
Forum section: electronics / repair

author: tcharron
author_rank: Newbie
timestamp: September 22, 2021, 03:23:35 pm
content: I just acquired a Fluke 75 cheap. It had a lot of problems, which I have largely fixed just by cleaning it up.I had to repair the elastometric connectors for the display and clean the contacts for the knob and reflow its solder joints just to see what was going on. Then, it had very bad mesurements after the 0-3VDC scale (it was reading 2-3 times the input). I fixed that by reflowing the rest of the solder joints on the board and subjected it to an ultrasonic cleaning. Only after all of this, it's almost usable now.My problem now seems to be some kind of stability issue.- When first powered up (after sitting for a while), the device reads around -0.001 volts on the VDC, then over about 3 seconds, migrates to -0.026 Volts.- Hooking this up to a bench supply, It reads voltages from 1-20V as about 0.3V high.- Then, shorting the leads, it reads about 0.3V, but over about 2-3 minutes this decays to a 0.1V level, then over the next 15 minutes that falls to +0.04V. It seems like it is an asymptotic decay.There may be a calibration issue, but the calibration of the device would not affect the "0" level, and calibration would also not explain the very slow tracking.I'd appreciate any ideas on what could be causing this.

author: tcharron
author_rank: Newbie
timestamp: September 22, 2021, 03:31:00 pm
content: A correction to my post... After removing the bench supply, I left the leads disconnected (not shorted as I stated).
Fluke 77 Repair or Give - Page 1
Forum section: electronics / repair

author: DugFluke77
author_rank: Newbie
timestamp: May 17, 2025, 01:59:43 pm
content: I have a Fluke 77 that is not responsive when I turn it ON with battery. If anyone needs one or would like to repair it for a small fee. If there is an easy fix, let me know. I looked for TP1 and TP3 but could not find the terminals. Please contact me.

author: DugFluke77
author_rank: Newbie
timestamp: May 17, 2025, 02:05:20 pm
content: I just looked on a commerce site and now I doubt it is worth repair.

author: Paceguy
author_rank: Regular Contributor
timestamp: May 17, 2025, 04:42:14 pm
content: I could use it for parts. I need a display for mine.
Fluke 77 Series 2 current measurement problem - Page 1
Forum section: electronics / repair

author: Robert Smith Eco Warrior
author_rank: Regular Contributor
timestamp: May 15, 2021, 08:36:13 am
content: Hi All,I was checking my off grid inverter grounding yesterday before connecting my oscilloscope. There was a very small voltage between battery negative and the inverter ground, also oscilloscope ground. I didn't think this would cause much current so as a check I tried my multimeter on the 10 Amp range and got nothing and then tried it on the 300mA range and got nothing. I was wondering if I had inadvertently blown the two internal fuses so thought I would just check across a fairly flat AA battery to check if the fuses were intact. Oddly I got a reading of 0.2A on the 10A input and 58mA on the 300mA input. The selector dial was not moved when doing the swap, just unplugging the lead from the 10A hole to the 300mA hole.Anyone had a similar problem or know what the problem may be?I shall try it again shortly but also try my son's two multimeters too to figure out what the reading is meant to be.

author: Robert Smith Eco Warrior
author_rank: Regular Contributor
timestamp: May 15, 2021, 09:34:41 am
content: I may have found a slight oddness..I have compared my son's extech multimeters and my fluke and they both do odd things when checking the current an AA battery can deliver. I think it must be the battery's capability to provide current when being connected across the different current shunt resistors. I shall try the multimeters on my power supply and various resistors. Maybe the fluke and extech meters are fine unless you try to test current across a pretty flat AA battery

author: mzacharias
author_rank: Frequent Contributor
timestamp: May 16, 2021, 01:54:31 pm
content: The results you got with the flat battery on each current input jack look completely normal to me.If the Fluke had a separate micro-amp function, which it does not, then the selector switch would be involved.In this case, the amp and milli-amp jacks are always connected to their shunt resistors, a few ohms for the milli-amps, and "point something" for the 10 amp function.This also explains why the current values were different.
Fluke 77 Series II-  Protection Device of Some Sort Cracked - Page 1
Forum section: electronics / repair

author: RobertM64
author_rank: Newbie
timestamp: August 12, 2020, 09:51:19 pm
content: Seen this on other posts regarding the 77, cracked high voltage protection device, but I'm not competent enough to know how to find a replacement. Some help would be appreciated. 2KV 9527. Thanks!

author: bd139
author_rank: Super Contributor
timestamp: August 12, 2020, 09:57:19 pm
content: That’s actually supposed to be like that. It’s fine

author: RobertM64
author_rank: Newbie
timestamp: August 12, 2020, 10:43:26 pm
content: That's crazy! But I've never seen such a straight failure induced crack, so you must be right! Thanks!

author: KMoffett
author_rank: Regular Contributor
timestamp: August 12, 2020, 11:38:29 pm
content: https://vetco.net/products/001uf-1kv-2kv-ceramic-spark-gap-capacitor

author: EEVblog
author_rank: Unknown
timestamp: August 12, 2020, 11:58:00 pm
content: Yep, completely normal, sparkgaps are designed like that.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 13, 2020, 10:29:10 am
content: Yep totally fine

author: TheMG
author_rank: Frequent Contributor
timestamp: August 13, 2020, 01:35:27 pm
content: They are very similar to a normal capacitor, but one of the steps in the manufacturing process the literally cut a slice into the top of it.This exposes the edge of the plates of the capacitor to air, which has a lower breakdown voltage than the ceramic dielectric. The idea is to provide a discharge path in the event of over voltage to avoid damaging the dielectric.
Fluke 771 mA Process Meter - Value of R27? - Page 1
Forum section: electronics / repair

author: kblue
author_rank: Regular Contributor
timestamp: June 23, 2025, 11:52:12 am
content: Greetings!I'm trying to repair a Fluke 771 mA Process Meter with some damage from leaking batteries. Before i got it, someone else tried to repair it. Sadly since then R27 is missing and i don't know the value of R27. Does anyone have a 771 and could take a look?Parts with severe corrosion-damage like U4 are already replaced with new parts from digitkeyI hope the unit survived./edit: R27 is marked 6043 - so it's 604k. Anyway, thanks!

author: D2236
author_rank: Regular Contributor
timestamp: June 24, 2025, 12:12:44 am
content: It may also be using the 4-character EIA-96 marking code (not standard) for precision 1% resistors. Using this code, 604 corresponds to 3.92 from the tables. The multiplier (3) means x 1000. This will result in a final value of 3.92 x 1000 = 3920 ohm. It can also be the standard 4-digit marking of 604 x 1000, adding to the confusion.Since 604k is not part of the E96 series (603k, 619k...), and not part of the E24 or E48 series, it is more likely that a precision 1% resistor with this marking will have a value of 3.92k.

author: kblue
author_rank: Regular Contributor
timestamp: June 24, 2025, 12:46:51 am
content: Someone did a measurement with his unit (resistor still in place) and in circuit its close to 300k (guess because of neighbouring resistors and invisible traces to other parts of the unit). Being a 3,92k 1% seems unlikely but yea ... these codes can be quite confusing.The unit seems to work just fine now, already did some measurements. Power consumption fits the manual, all lights are working as well. Checking wiki E96 (1%) has 60.4 as an option, so it seems fitting.

author: D2236
author_rank: Regular Contributor
timestamp: June 24, 2025, 01:09:37 am
content: Well, then I suppose you have the correct value, since you get accurate measurements.
Fluke 773 Milliamp Process Clamp Meter Repair - Page 1
Forum section: electronics / repair

author: ElektroAlp
author_rank: Newbie
timestamp: January 12, 2021, 05:17:21 pm
content: Hello,I need help to repair a burnt Fluke 773 Milliamp Process Clamp Meter. I bought it as a not working device. I guess previous owner connected the Voltage input to mains or at least something above 30 Volts. It is obvious that i have to change the burnt items. I have already ordered the orange relay: EA2-5NJ NEXEN. I don't know the values of the 5 Components:C454, C216, R252, L7? (I don't read the "7" very good that is on the right of L5),L8(I don't read the "8" very good that is on the left of L4). Can somebody who has this Fluke 773 measure these capacitors, inductors and the resistor? Or even better will be the Service Manual.Thanks in advance for any help.

author: srmahaffy
author_rank: Contributor
timestamp: January 08, 2023, 08:09:29 pm
content: Hi,I know this post is very old, but wanted to see if you still need help. I just bought a 773 on eBay.

author: tfm
author_rank: Contributor
timestamp: October 15, 2025, 12:53:37 pm
content: Hi,@srmahaffy, this is an old thread, but can you upload hi-res photos of your 773, in case you still have it?
Fluke 77/BN DMM needs new Fusible Resistor (R1) - Page 1
Forum section: electronics / repair

author: gcc
author_rank: Contributor
timestamp: August 11, 2023, 09:38:41 pm
content: Hi, I am looking for a source for a replacement Fusible Resistor (Manufacturer's P/N: FA8466) for a Fluke 77/BN. Anyone have a source for this part? The only other info I have on it is "MF, 1K, Fusible, 2%". Thanks for any help on this.

author: gcc
author_rank: Contributor
timestamp: August 11, 2023, 10:27:41 pm
content: I think I found a replacement part from another thread (https://www.eevblog.com/forum/testgear/fluke-77-replacement-for-r1-(1k-2w-fusible-resistor)/msg3303400/#msg3303400).

author: floobydust
author_rank: Super Contributor
timestamp: August 12, 2023, 04:55:25 pm
content: What part did you go with?
Fluke 787 - Page 1
Forum section: electronics / repair

author: kazik70
author_rank: Contributor
timestamp: December 15, 2021, 05:26:03 pm
content: Hello, I need help with a broken fluke 787.I can see absolutely no damage, cold solders, short circuits etc ..The meter does not make any measurements, it is constantly looking for the range on the resistance test.The continuity test is still active.The display works, the buttons work.Is there anyone who has experience with this meter and can help? Maybe someone has a diagram?I noticed that the black "com" banana jack is shorted to + 9v battery. Can it be like that in general? It seems illogical to me, but after long measurements I am not sure anymore.
Fluke 787 Help (I know you that this is a long shot) - Page 1
Forum section: electronics / repair

author: imechura
author_rank: Newbie
timestamp: December 20, 2021, 11:52:00 am
content: Hello,I had a problem with my fluke 787 process meter. I removed the a MOSFET from the main board and wrote down the number FR320 which I read from the MOSFET. but now I've lost the MOSFET and I can't find anything that is an exact match for that part number online. I already know that it was a bonehead move.I was wondering if anyone knew the part number or if anyone with a similar meter laying around might be so kind as to crack it open and retrieve that part number for me.this is the only decent meter I have and I'm already kicking myself for screwing it up.thank you,

author: scl
author_rank: Contributor
timestamp: December 20, 2021, 03:35:41 pm
content: Best guess is IRFR320PBF.Hope that helps.
Fluke 787 Processmeter locked in UnCAL mode - Page 1
Forum section: electronics / repair

author: tru3533
author_rank: Regular Contributor
timestamp: October 02, 2025, 09:35:46 pm
content: For no reason my Fluke 787 Processmeter got locked in UnCAL mode(showing UnCAL on the screen all the time)The obvius way is to send it in for calibration, but I feel the urge to try to calibrate the Fluke myself.From what I have found out so far, MET/CAL program from Fluke is needed and some config files for the 787Anyone who can help me out in the right direction?

author: coromonadalix
author_rank: Super Contributor
timestamp: October 03, 2025, 06:00:58 pm
content: it was asked in 2024https://www.eevblog.com/forum/repair/fluke-787-processmeter-the-display-read-uncal/there is some cal modes / procedures for a 189 on youtubenot sure if the 787 can enter manually in calibration and manually register the values ??but in the end your process meter would not be valuable as a reference material ?
Fluke 787 Processmeter the display read "UnCal" - Page 1
Forum section: electronics / repair

author: azemati
author_rank: Contributor
timestamp: August 27, 2024, 10:08:33 am
content: Hello dear friendsI have a Fluke 787 Processmeter which unfortunately gives an "UNCAL" message please guide me to fix this problemThank you

author: indeterminate
author_rank: Regular Contributor
timestamp: August 27, 2024, 11:12:18 am
content: You will need to recalibrate the meterRead the manualhttps://assets.fluke.com/manuals/787_____cmeng0100.pdfdo you have access to the required test equipment & software

author: azemati
author_rank: Contributor
timestamp: August 27, 2024, 11:58:01 am
content: Unfortunately no
Fluke 789 not starting up  - Page 1
Forum section: electronics / repair

author: longboard1210
author_rank: Contributor
timestamp: November 01, 2020, 01:12:40 pm
content: Hi guys i have a Fluke 789 that will not turn on,i have looked at the two forum posts here but mine is diferent,The meter draws no current when turned on so looks like i have a power rail down,however i am sruggling without a schematic or block diagram board is good with no damage or delamination to itDoes anyone have any board info for this meter seems a shame to scrap it

author: smaultre
author_rank: Regular Contributor
timestamp: November 01, 2020, 04:21:33 pm
content: Check battery, check IC power rails, check flash\generator, activity when button is turned.
Fluke 789 Repair - Page 1
Forum section: electronics / repair

author: npnpnp
author_rank: Newbie
timestamp: January 02, 2019, 02:06:44 pm
content: Hey everybody,I recently got a damaged Fluke 789 Processmeter.The device powers up and only shows "unCAL" - as far as I know this is the common indicator of this meter that something inside is definitely wrong.Inside there is a black spot on the PCB next to the fuse. I think some traces and/or devices were broken due to a shock.I already tested the obvious traces and devices, everything seems to be ok. Moreover, the device does not measure anything, but the Loop Power function provides a voltage.I already found a similar topic:https://www.eevblog.com/forum/repair/fluke-789-repair-safety-implications/Unfortunately, the damage of my meter is not located at the same spot.Do you guys have experience in reparing this meter or do you have more knowledge about the wiring inside the PCB? I know this is a very specific question.I am not able to follow the trace at this section and tell if there should be a connection or not. Fluke does also not provide schematics.Best regards

author: coromonadalix
author_rank: Super Contributor
timestamp: January 02, 2019, 07:04:00 pm
content: Damn a delaminated board in two cases, corrosion ?? leaked batteries ??As i see it you vave 3 vias, 2 on the same cr1 pad and the small one in the center, you have to know where it / they goes ... ask the linked thread "atsthng" guy, maybe he can help to trace itSometime you can put a small very bright flashlight against the board and see the pcb traces layers and see where it can go ...

author: npnpnp
author_rank: Newbie
timestamp: January 02, 2019, 09:50:42 pm
content: According to some black marks inside, there seemed to be an electric shock. atsthng also discovered a wrong 10A fuse inside his meter (should be 440mA). I sent a message to him.I think, the small via in the center is damaged. I managed to contact it from the other side of the PCB and there does not seem to be a trace to any other point.

author: Solderingfanatic
author_rank: Newbie
timestamp: August 10, 2019, 01:42:57 pm
content: Well, I got a used 789 Fluke processmeter last year. Working fine, although I didn't use it frequently, when suddenly, stopped working. Something like losing battery contact, the LCD going on/off. After some time it simply died completely. I dissasemled it completely, till the last screw, found absolutely nothing. Note that it was not burned or something similar. Anybody has some repair manual or electric diagram available? I will post pics of the PCB next week.

author: jorgeescobar
author_rank: Newbie
timestamp: October 09, 2024, 01:52:34 am
content: hola, me podrías ayudar, tengo el mismo fluke y se quemo el transistor q20 y no se cual es, ya que se reventó, tu me podrías ayudar con la numeración del transistor?

author: Ugur
author_rank: Regular Contributor
timestamp: October 10, 2024, 12:13:21 pm
content: Check if CR1 and CR2 are good. CR1 one end should be connected to COM, the other end should be connected to A/Loop PWR (W9) and a pad under the selector switch.
Fluke 789 service manual or some advice on the burnt resistor  - Page 1
Forum section: electronics / repair

author: KennyX
author_rank: Newbie
timestamp: December 18, 2020, 12:13:01 pm
content: I own a fluke 789 process meter for almost 3 years, recently its stop read or output milliamp signal, so i open the casing to do physical inspection and found the incoming resistor right after fuse holder is burnt ( prolly due to mishandling from my worker ) , the resistor body is destroyed and hardly recognize what printed on it.I was thinking that resistor could be some kind of zero-link resistor ? or it does have a rated resistance ?Those picture of 789 shared and circulated on the internet have different component layout to mine, guess this unfortunate 789 is a newer model, seeking for service manual and no luck to get em..Is there anyone in here can provide good advise or perhaps share me the snap-shoot of your 789 at here will be greatly appreciated ~ i pray that you will have a really good time in 2021KennyX
Fluke 79 III -OL- in vdc,mvdc and won't measure resistance - Page 1
Forum section: electronics / repair

author: Mark24
author_rank: Newbie
timestamp: April 12, 2024, 06:08:25 pm
content: GreetingsA fluke 79 III that show -OL- on Vdc and mVdc and won't measure resistance all without probes using a new batteryVac show (0.00) normal and Buzzer , Diode mode worksAttached photos for the DMMI dont know to what to check nextAny suggestions?

author: m k
author_rank: Super Contributor
timestamp: April 21, 2024, 02:35:11 pm
content: One possibility is that ohms voltage source is on all the time.You should be able to check that.

author: Mark24
author_rank: Newbie
timestamp: May 23, 2024, 09:23:07 pm
content: Thank you for the informationon ohms mode the probes fluke measure 1.23v if the probes shorted the DMM display -OL- and the "-" flasheson vdc mode they measure 0.99v the DMM display -OL-is that what you mean by (ohms voltage source)?

author: m k
author_rank: Super Contributor
timestamp: May 24, 2024, 01:33:30 pm
content: Yes.In theory probes can have what ever voltage when ever, but it would be overly complicated if VDC mode had an initial probe voltage.So normally Ohms measurement style is active and VDC passive, means that the same internal current is measured but for that VDC mode uses external voltage.When probes are shorted and Ohms is -OL- it means that the measured value is negative.For that there must be incorrectly balanced internal measurement and reference voltages.Without VDC mode problem it could be just an adjustment of zero level.When VDC mode has probe voltage it means that disconnection of internal measurement voltage for Ohms has failed.Can be just a bad switch somewhere, but the machine has many integrated switches.Series II manual has schematics, maybe series III is close enough.
Fluke 79 Series II shows 10.5 megohms when open circuit - Page 1
Forum section: electronics / repair

author: Tim M
author_rank: Newbie
timestamp: April 07, 2024, 06:07:24 am
content: Hi All:The display shows 10.5 (this can vary from 10.5 to 10.ohms open circuit and when the leads are shorted it displays .4 ohms. Low ohms works correct as do ACV and DCV when compared to another meter. When shorting the leads in ACV and DCV modes the display is 0.00 When measuring ohms the result is the parallel combination of resistor you are measuring with 10.5 megohms in parallel. I have measured the fusible resistor with another meter and it measures 1.12K. I am not sure what the tolerance is on that part. I have downloaded the service manual but I am not sure where to go from here or what further tests I could perform. Any assistance appreciated. Thanks in advance.Edit: The battery is new and I now see that the fusible resistor is speced as a 1% part so my fusible resistor R1 is out of tolerance at 12% high. I paralleled it temporarily to bring it back into spec and the reading did not change.Tim

author: floobydust
author_rank: Super Contributor
timestamp: April 08, 2024, 07:40:56 pm
content: Welcome to the forumsI would say it's not the fusible surge resistor R1 1kΩ or the PTC causing the open-circuit Ohms reading 10.5MEG because they are so small in comparison to the input resistance and their purpose is to protect the Ohms-source. So if they vary 20% it's still nothing for a couple kΩ to the 10MEG in the divider.Usually it's a damaged protection clamp transistor Q1 or Q2 that is leaky. You can lift one leg to disconnect them and see if the reading persists.It rarely can be the protection MOV's leaking RV2, RV1.A dirty PCB or rotary switch, especially around the Z1 9.999MEG, Q1&Q2, across RV1,2 etc. Use IPA and a Q-tip to clean up old flux and any battery leakage etc. and let it thoroughly dry out.Beyond this I think the DMM IC can get zapped and a damaged CMOS MUX internal switch give the leaky Ohms reading.Another way to flush out the leaky part is to apply heat - with your finger, soldering iron etc. and find what makes the reading jump significantly.

author: Tim M
author_rank: Newbie
timestamp: April 09, 2024, 10:01:37 pm
content: Thanks very much for the response. These sound like excellent ideas. I will investigate and report back.Tim

author: Tim M
author_rank: Newbie
timestamp: July 08, 2024, 09:08:31 pm
content: I want to close the loop on this. The problem was in fact the MOV RV1. I replaced RV1 and RV2 with Littelfuse V575LA10P as suggested in other posts here. The meter is working well again. Thanks again floobydust for your suggestions.
Fluke 79III water damage - Page 1
Forum section: electronics / repair

author: budhafoo
author_rank: Newbie
timestamp: June 19, 2015, 03:14:34 pm
content: As stated in the subject. Any schematics? Where do I start to get this back to life.. Tried cleaning it with brush and alcohol. Havent poke around with my meter yet. Hope just the LCD went bad?

author: retiredcaps
author_rank: Super Contributor
timestamp: June 19, 2015, 04:53:47 pm
content: Quote from: budhafoo on June 19, 2015, 03:14:34 pmNo schematics for the 79 III that I know of.To start, tell us what works and what does not.1) Does DCV work when reading a 9V battery?2) Does ohms work when reading a 1k ohm resistor?3) Does continuity mode beep when shorting out the probes?4) Can you post a clear focused picture of the pcb?5) Does it turn on?

author: budhafoo
author_rank: Newbie
timestamp: June 21, 2015, 07:46:54 am
content: It doesn't turn on. Here are some pics..Where should I start ?TIASent from my Nexus 5 using Tapatalk

author: ModemHead
author_rank: Frequent Contributor
timestamp: June 21, 2015, 01:48:14 pm
content: A very thorough inspection with magnification is always a good practice, especially if any sort of corrosion damage is a possibility.Check the unit's current draw with a fresh 9V battery, with the switch off and the switch on. Should be zero when the switch is off. I can't remember exactly what normal draw is for a 79-III, but it is probably in the 1 to 2mA ballpark.If the current draw is too low, it could be battery connections, switch contacts, or some of the power supply circuitry has failed open. If the current draw is about normal, the processor and all could be running normally and just the display has failed. If the current draw is excessive, then some of the power supply circuitry has failed short or one of the chips is bad.

author: Grapsus
author_rank: Regular Contributor
timestamp: June 22, 2015, 05:54:01 am
content: If you think only the LCD is bad, you can put the meter in continuity mode and it should still work.This 79III looks a little like the 79II but with both digital and analog chips regrouped into one and it still uses the same rotary switch design from the 70s. The possibility of a repair here will probably boil down to the question whether the main chip is dead or alive.

author: edisitaru
author_rank: Contributor
timestamp: January 29, 2021, 06:41:07 pm
content: HelloIf you still have the motherboard, I'm interested. I need the rotary switch.
Fluke 8010a AC Overrange HELP - Page 1
Forum section: electronics / repair

author: HendoNZ
author_rank: Contributor
timestamp: April 16, 2021, 04:16:09 am
content: Hi all,I recently got a Fluke 8010a, but unfortunately the AC side reads overrange, no matter the input. I did some hunting around the unit and found there's a problem with the U8 board.Anyone solved this kind of issue before?If not, I'll be on the lookout for a replacement board. So if anyone out there has a parts unit that they are will to let go of - I would be very grateful.Cheers
Fluke 8010A: High test voltages on Resistance/Diode mode - Page 1
Forum section: electronics / repair

author: WeekendHobbiest
author_rank: Newbie
timestamp: September 20, 2019, 07:46:57 pm
content: Hello, everyone. My Fluke 8010A is giving me some trouble and I would like some help. Quick backstory on the meter: fleabay purchase nearly a year ago, like-new condition. Used by me as a secondary meter for V and I measurements (works well). Noticed recently that diode and resistance functions are faulty. Not sure if the problem was there before.When testing diodes, the rating the meter gives exceeds what the diode's VF should be. When testing resistance, I get different readings. If I measure a resistor with the meter set to the proper range, the meter gives a good rating, but if I cycle through the ranges, I'll get faulty readings on some ranges.A visual inspection of the board shows nothing concerning. I downloaded the service manual to see if I could figure out what's wrong. I found a few out-of-tolerance resistors (R1, R11 and R12) and replaced them but that wasn't the problem. The input circuitry checks out, but from there I had a hard time figuring out how to follow through the switches on the schematic. Since the board had a low component count, I took a stab in the dark and tested all the resistors and diodes on the board and they're fine. I have no tools to test caps. Fluke's resistor network measures OK, and the reference voltage IC is spot on.Looking closer at the service manual, on page 13, a list of voltages and current are given for the Ohmmeter. The following is what my meter is outputting versus (what the service manual rates):200 Ohm: 2.838v - .93mA (< .25v - 1.3mA)2K Ohm: 2.838v - .93mA (> 1v - 1.3mA)20K Ohm: .988v - 9.5uA (< .25v - 10uA)200k Ohm: 2.814v - 27uA (> 1v - 35uA)2M Ohm: .524v - .1 uA (< .25v - 0.10uA)20M Ohm: 1.493v - .2uA (> 1.5v - 0.35uA)So my problem is high output voltages with slight undercurrent. I guess this is why readings are off.Any thoughts or suggestions as to where I should look next? I'm pretty much a tinkerer with electronics and I've hit a wall in figuring out what's wrong here. I would love some hints or advice. Thanks.Service manual:http://assets.fluke.com/manuals/8010A___umeng0200.pdf
Fluke 8020A diagnosis of contact problems - Page 1
Forum section: electronics / repair

author: nightfire
author_rank: Frequent Contributor
timestamp: June 25, 2022, 08:39:58 pm
content: I am proud owner of a Fluke8020A in cosmetically good condition. Got it for cheap as the seller on ebay mentioned some issues measuring current- like "you have to plug in sometimes several times to make it work".The test leads are probably also the same age like the DMM, but are working. I disassembled the device, and internally it looks fine, the 4mm jacks are rock solid soldered to the PCB.I will still have to use it under test conditions to determine whats on it, but in this case I would suspect some oxidized switches.Question here: What is the best way to clean them, as they are not really disassemble-friendly?

author: bob91343
author_rank: Super Contributor
timestamp: June 26, 2022, 04:47:06 am
content: I think the best way to get reliable operation of the switches is to use them frequently. I have opened mine and the switches are nearly inaccessible. Operating them many times increases their reliability and I think is the way to go.
Fluke 8020A Repair HELP MULTIMETER DOES NOT WORK ANY RANGE - Page 1
Forum section: electronics / repair

author: elnegociadorweb
author_rank: Newbie
timestamp: August 15, 2020, 10:32:05 am
content: Hi i have a problem with my dad's fluke 8020A. The screen is fine, it turns on and moves the points on the screen (. . .)Please help:-MULTIMETER DOES NOT WORK ANY RANGE- the on-screen indicator of the battery low is always active (BT)--capacitors ok-pcb clean-Battery New

author: retiredcaps
author_rank: Super Contributor
timestamp: August 15, 2020, 06:47:15 pm
content: Fluke 8020A manual athttps://archive.org/details/FLUKE_8020B_Instruction/page/n75/mode/2upBT indicator - see page 4-11.As no readings, check R2 fusible resistor. It should be 1k ohm.

author: elnegociadorweb
author_rank: Newbie
timestamp: August 16, 2020, 10:14:47 am
content: Hi, thanks, the multimeter is the 8020A. Will the 8020b manual serve me?

author: retiredcaps
author_rank: Super Contributor
timestamp: August 17, 2020, 03:08:59 am
content: A manual here.https://www.manualslib.com/manual/564456/Fluke-8020a.html

author: coromonadalix
author_rank: Super Contributor
timestamp: August 17, 2020, 10:00:12 am
content: I was thinking it may be based on an icl7106 dmm chip, but Fluke had different ic instead ?? But it was supposed be an 7106 predecessor ??Some story : or copy cat lollhttps://hackaday.com/2017/01/31/get-to-know-3%C2%BD-digit-adcs-with-the-icl71xx/https://www.eevblog.com/forum/testgear/history-of-the-fluke-8020-series/I recall they where still Intersil branded ??Some display revival and noteshttps://www.sbprojects.net/repair/fluke8020a/index.php

author: coromonadalix
author_rank: Super Contributor
timestamp: August 17, 2020, 10:08:39 am
content: And this section:To make it functionally different, Intersil masked off the switch that allowed the 429100 to auto-range between 200mV and 2V ranges (which was a Fluke patent). This made the 7106 unsuitable as a direct, drop in replacement for the 429100. But Fluke found out that the silicon inside the 7106 still sported a Fluke logo, and a lawsuit ensued. This was settled out of court, since Fluke could not afford to lose Intersil’s fab facilities. But the 7106 was now available to all for use and would end up inside a large number of products built in those days. You can read  who worked at Fluke during the time reminisce about this over at the EEVblog forumAnd this sale if you need a new dmm chiphttps://www.ebay.com/p/1845868863

author: elnegociadorweb
author_rank: Newbie
timestamp: August 18, 2020, 10:05:23 am
content: Hi.upgrade:r1: okr2: okthe fluke 8020a will not turn on from the battery eliminator connector!I suspect the lm358nWhat voltages should the 429100 chip have?
Fluke 8050 wrong measurements? - Page 1
Forum section: electronics / repair

author: Lokian666
author_rank: Newbie
timestamp: August 07, 2019, 11:03:13 pm
content: I have a fluke 8050A DMM that I purchased for $30.(1).When I measure 1.5 volts on 2 volts range, the meter displays 15406. Is this 1540.6 mV?(2). When I measure 1.7 kilo ohm on 2 kilo ohm range, the meter displays 17246.The DMM needs repair/re-calibration?Thanks

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 07, 2019, 11:29:49 pm
content: It would seem that the display misses a decimal point. Possibly a contact problem with the LCD display.Maybe you'll find something in this thread:https://www.eevblog.com/forum/repair/fluke-8050a-repair/There's quite a few projects for replacing the original display on these. Couple examples:https://diycrap.blogspot.com/2014/01/fluke-8050a-display-repair.htmlhttp://vondervotteimittiss.com/belfry/?p=129http://vondervotteimittiss.com/belfry/?p=180If you don't have the manual:http://assets.fluke.com/manuals/8050a___imeng0200.pdf

author: lowimpedance
author_rank: Super Contributor
timestamp: August 08, 2019, 12:01:19 am
content: One other thing to try is to exercise the switch banks first, maybe use some contact lube too, and see if that restores the missing decimal point before investigating the LCD contacts.

author: Lokian666
author_rank: Newbie
timestamp: August 11, 2019, 01:58:42 am
content: It turned out that the problem was with either the flex cable or LCD. I played around a bit with both. The missing decimal point came back.
FLUKE 8050A - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 26, 2022, 09:57:57 am
content: Hi there! I am trying to identify the following integrated circuit: SL62516, it is mounted on the RMS converter of the FLUKE 8050A (see photo).... Thank you for your precious help

author: coromonadalix
author_rank: Super Contributor
timestamp: November 26, 2022, 10:36:37 am
content: maybe the 8860a used the same rms convertersearch for the service manualhttps://elektrotanya.com/fluke_8860a_sm.zip/download.html#dl

author: MikeK
author_rank: Super Contributor
timestamp: November 26, 2022, 09:27:57 pm
content: And the schematic for the 8050A doesn't show that individual IC, but shows the entire module as "U32 Hybrid RMS Converter":https://xdevs.com/doc/Fluke/8050A/

author: Andy Watson
author_rank: Super Contributor
timestamp: November 26, 2022, 10:12:36 pm
content: The logo is National Semiconductor, but nothing appears by that part number in their databooks. Probably a specially selected piece labelled with a house part number?Conssensus seems to be that it's a dual op-amp.https://www.eevblog.com/forum/chat/fluke-8050a-473777/msg456624/#msg456624https://www.eevblog.com/forum/chat/fluke-8050a-473777/msg80651/#msg80651https://www.eevblog.com/forum/repair/fluke-8050a-true-rms-u32/msg626439/#msg626439

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 27, 2022, 05:28:19 pm
content: Good evening; thanks for your feedback everyone!

author: Andy Watson
author_rank: Super Contributor
timestamp: November 28, 2022, 07:10:14 pm
content: I have just cracked-open a 8010A. It contains a similar RMS hybrid (possibly an earlier version) with a 473777, however, it has a Signetics logo.Looking at the service manual for the 8860A, moduel A4 AC/DC Scaling PCB Assembly BOM (page 5-18 on my copy, but YMMV), it gives U19 as:U19 IC, LIN, SELECTED 473777 89536 473777Looking at the service manual for the 732A voltage standard (module A5 Reference PCB Assembly BOM, page 5-20, but again YMMV), lists U3:U3 IC, LIN, OP-AMP, DUAL COMPENSATED 473777 12040LM358NI conclude that it's an LM358 - possibly selected for tolerence.

author: MikeK
author_rank: Super Contributor
timestamp: November 28, 2022, 11:53:03 pm
content: That's some good sleuthing there. OP never did say what was wrong with his module.
Fluke 8050A battery option conversion info sought. - Page 1
Forum section: electronics / repair

author: Paceguy
author_rank: Regular Contributor
timestamp: October 14, 2024, 10:53:12 am
content: Hi everyone,I have a couple of Fluke 8050A's with the battery option and I would like to remove the dead batteries and turn them into AC line operated only units. Has anyone done this and could you share the conversion info with me?Much appreciated,Thanks!

author: Martian Tech
author_rank: Regular Contributor
timestamp: October 15, 2024, 02:03:56 am
content: https://youtu.be/Gvo9_ZNc9qE

author: Paceguy
author_rank: Regular Contributor
timestamp: October 15, 2024, 04:56:50 pm
content: Thank you Martian Tech, great step by step video without having to cut traces. That's exactly what I was looking for!
Fluke 8050A LED display with continuity tone - Page 1
Forum section: electronics / repair

author: jpwolfe31
author_rank: Contributor
timestamp: June 21, 2021, 10:39:04 pm
content: Another Fluke 8050A LED display project, but this time with a continuity tone addition.There are two versions of the continuity tone software. The first version is named LED_8050A_TM1637_Display_Cont. This code enables use of the TM1637 LED Display driver. It also adds a continuity test with a tone using the output to the LED display to determine if there is continuity. Continuity is checked each time the display is updated (2 times per second) when the 8050A is set to the ohm function in the 200 range.The second version is named LED_8050A_TM1637_RT_Cont. This version is the same as the first version but instead of using the output to the LED display to determine if there is continuity, the software samples the voltage on the rear lead of R8 (the 220k ohm 2 watt resistor) of the 8050A. This provides for a real time continuity check without any display update delays. Voltage for the continuity check is read at the rear lead of R8 through an added LF347 op amp configured as a voltage follower buffer having high input impedance. This is followed by another LF347 op amp configured as an inverting 10x amplifier. This produces a voltage in the correct range for the ATmega328P to read through its analog input at A5.Both of these versions could be used without changing the original display if one just wanted to add a continuity tone.Code and full description here:https://github.com/jpwolfe31/8050A-Continuity-Tone-and-LED-Display
Fluke 8060A power switch replacement - Page 1
Forum section: electronics / repair

author: philwong5176
author_rank: Unknown
timestamp: July 11, 2024, 03:57:09 pm
content: Hello:After years of use, the slide switch to my Fluke 8060A fell apart today, the plastic tab broke off from the body that’s soldered to the main board.The service manual description is “SPD Slide Switch”, which tells nothing about the voltage or current requirements. Also the side of the tab has to be small enough for the green switch cover.Does anybody have a part number for this so I could order it from Mouse/Digikey?Thanks.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 11, 2024, 04:18:01 pm
content: https://www.eevblog.com/forum/repair/fluke-8060a-switch-trouble/and you have an other member who do repairs on theses he may have some hints for you ?

author: GLouie
author_rank: Regular Contributor
timestamp: July 12, 2024, 12:31:21 am
content: My first generation 8060A manual, circa 1982, shows my power switch as a model GI-116-0005 made by C-W Industries. Both Digikey and Mouser show them as non-stocked, so you have to order 500 of them.
Fluke 8100A Nixie Tube DMM - Broken! - Page 1
Forum section: electronics / repair

author: doombot1
author_rank: Contributor
timestamp: February 10, 2024, 12:32:42 am
content: Howdy all!I've got 2 Fluke 8100A DMMs. They're pretty neat things - love the nixie tube display. One of them has always been a bit wonky, and the other one, at least until a month ago, worked wonderfully. A 50-plus year old DMM that was still accurate to +/- 0.005. Incredible! Anyways... I brought my girlfriend downstairs to show her, and tried to turn it on, and ... nothing. The tubes no longer light up. Busted out the thermal cam, and one of the transistors seemed to be getting kinda hot - swapped it out, and that fixed nothing. (and of course, checked all fuses).The other DMM does turn on, and all of the tubes work - but the issue is that they all show zero, regardless of the inputs on the front panel. When a voltage is applied, they sometimes briefly (like, almost too fast to capture at 120fps slo-mo) flash to a different number. Not sure if it's to the correct number, though. But - that one's tubes turn on. So - I tried swapping both the LV and HV transformers from both units (separately), and they still work identically to beforehand. Also tried swapping all three of the DIP chips, and same result. So... I ruled out the easy things.Short of literally desoldering and checking every single component one-by-one, does anyone have any ideas as to what could be wrong with either meter?? Manuals for these can be found on Ko4bb. Before the good one died, I had both meters turned on and on my desk for about 3 hours, and was using a scope & DMM to probe points in both DMMs, in an attempt to fix the broken one (which is now the more-working of the two; the one with the tubes that turn on but show zero). So maybe the (previously) good one died later because I'd just been using it too long or something? It didn't die while it was on... again I used it for 2-3 hours, turned it off and put it on a shelf, and an hour or two later, pulled it back out to turn it on and got nothing. The line switch does work - I do get voltages in the circuit, but they are all over the place - and I can't leave it on for too long to test because the transistor gets hot (Q5).Any ideas? Thanks for the time of day - any help would be greatly appreciated. And of course, let me know if there is any other information that would be of use.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 10, 2024, 08:04:39 am
content: There is a manual around, at least for the 8100B, that is very similar. This include schemantics and quite some troubleschooting information. One could check the supplies and a few more voltages. Especilly the unit that shows zeros one can check the ADC input and intermediate signals at the ADC to see if the problem is before the ADC, at the ADC or in the display part.