Fluke 8060A Somewhat Functional

[Christine1953]

Hello Everyone,
This is my first post here!

I have an old 8060A that was given to me many moons ago because it appeared to be DOA, and it's been sitting in my junk box for at least 15 years untouched. When I received it, it probably had less than 20 hours of use, and since we moved on to something else in the shop, it was discarded.

It turns out that if you power it with the cable, it fires right up, although there are some issues. It looks like a nice meter. My question is should I try to repair it, or toss it.

I've worked on lots of equipment, so getting in there isn't a problem, and I have good tools, but I'm not all that familiar with working on test equipment. I was in broadcast, and when the test equipment broke down, we just sent it out for repair

I have the users manual with the schematics and such, and have read some of the blogs/Youtube repair videos on repairing these units, but I could use some help navigating the lay of the land so to speak when it comes to repairing it.

Here's what I know, and what I've done so far. I've got it to fire up. Display is good, passes the ratio test, and the switch logic test. Resistance somewhat works. Accuracy diminishes as the resistance increases. In the M ohm area it's out of whack by at least 20%. The continuity and buzzer button works. DC/AC voltage functions do not work at all, just gibberish, and the meter does not zero out. HiZ DC volts function operates/tracks normally following a variable supply on the 200mv and 2V scale as it should. I have not yet checked the ammeter section. I took the unit apart and it appears very clean on the inside and no capacitors are leaking, but I will do a more through investigation later to confirm. Leaking capacitors seem to be an issue with these units so I'll probably just shotgun them all when I do the repairs.

So to summarize:
Battery has a bad connection to the board.
AC/DC voltage function not working.
Amps, Hz, dB, REL functions are untested.
Voltages at the test points have not been checked.
Unit probably needs a total calibration after the repairs.

If anyone has seen these issues and can point me in the direction of some discussions that address the problems I would most appreciate the help! Also, I see the owners manual mentions several times about being careful about handling the boards because of sensitive components and static discharge, but I regularly see in the videos people with little or no protection handling them. Are they touchy? I always use a wrist strap, work on a wood benchtop, and have a good soldering station.

Well that's it for now, and thanks for your help!
Christine

[J-R]

My first thought is check the 1K fusible resistor R2.

Beyond that, I would suggest checking every function and range since then you will have a really good idea of which part of the schematic is the likely culprit.

[lowimpedance]

As it has been sitting for years without use the switches could have oxide build up , so a good 'exercise' of each button is in order.
Also definitely replace those electrolytic caps.
Odd the battery connection was bad after only 20h operation , check the continuity from the battery tabs to the pcb. perhaps the power switch or the ext power in jack are iffy too.

[AVGresponding]

Getting some deoxit or similar in the switches is for sure a good start. When you compile a BOM for recapping, bear in mind later versions have a separate TRMS daughter-board, and this means 1 less crapacitor to replace.

[rsjsouza]

Welcome to the forum.

Fluke 8060A meters are still quite useful in the field, so definitely don't toss it.

If possible, could you post hi-res photographs of its interior? This could help further with any diagnosis.

As for the symptoms, as others have said switch contacts might be a problem.

Resistance somewhat works. Accuracy diminishes as the resistance increases. In the M ohm area it's out of whack by at least 20%.

I don't know your level of expertise, so that might be useless but it is a common error. When doing hundreds of kΩ or MΩ measurements, please do not touch both leads, so you don't add your body resistance to the measurements.

[rodcastler]

There's this thread that may help as well:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

[Christine1953]

Thanks everyone!
 I'd say my expertise level is OK. I was a pretty good trouble shooter back in the day, but I've been away from it for a long time, so let's call it "a diamond in the rough". I think the issue with the battery clip is nothing more than a bad connection somewhere along the line. I'm suspecting the switch in the power jack. When I first started playing with it, I put a battery in and nothing. Then I just hit the side of the case with my knuckles, (impact maintenance), and it came to life. I can trace that out, but for now I'll just use the jack for power. I have some deoxit so I'll clean the switches. I can open it up separate the boards and take some pictures to post, and then we can get a cap list together. I probably have most of what I need on hand. And, I'll go ahead and test the rest of the functions, and check R 1 and 2. Give me a day or two on the results.

The meter is in nice shape and I'd like to get it up and running if possible. If I remember correctly, it was quite pricey for the time. Thanks! C-

[Christine1953]

There's this thread that may help as well:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

Thanks! It's a long thread with lots of history, but I'll work through it. Maybe I need to ping the designer personally! LOL

[Christine1953]

First off thanks for the help. And, I'm not used to this style of forum so I probably need some help in posting my progress. ( I'm such a Luddite)! I'll just reply to someones comment in the meantime until I get things under control.

[Christine1953]

I took a few shots of the board and display. The board and the display look great! I see no leaking capacitors (at least from the top view) I inspected the board thoroughly and there is zero corrosion anywhere. It looks like this is rev. H S/N is 3620934. The display is very clean! If we need any pics of a certain area, just let me know.

[Christine1953]

I made some progress. Battery clip was bad. Loose rivet. I replaced it thinking that was the problem, but no dice. I'm still suspecting the switch in the side power jack. I cleaned all the switches and that helped. Ohms (all settings) now working and I'm getting reasonable readings. DC readings are now working on the 200mv and 2v positions. 20/200/1000 not working see the picture. I seem to remember seeing something about that in the troubleshooting section. It sounds like this is a common problem. If anyone has some suggestions please let me know. As I said, I'm unfamiliar with the "design language" used in test equipment, so when I look at the schematic it can be a bit puzzling. I'm guessing by the time I'm done I'll have a much better idea of what it is about. And, it doesn't help that I'm somewhat dyslexic LOL! Whenever there are a lot of switches and parallel wires on a schematic it's somewhat problematic for me. I can work through it, but it takes some time.

Also I have some broken buttons. two of the tan ones. The plastic must be brittle and I'll have to glue them in place or something.

I'm not sure how to test the AC functions. All I can think of is to use a variac with a current limiting resistor, and maybe making a voltage divider with some resistors??? I'm pretty unsure there and I really don't like playing around with line voltage. So if anyone has an idea that would be great.

I'm pretty encouraged at this point. After doing a close inspection, the meter is in excellent condition considering it's age. The caps all look good and there's no leakage or corrosion that I can see. I'm planning on replacing all of them as soon as I get things a little more under control.

I'll see if I can the readings from the test points tomorrow, for some more clues. I just ran out of time today. Thanks again for the help!
C-

[tautech]

There's this thread that may help as well:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

Thanks! It's a long thread with lots of history, but I'll work through it. Maybe I need to ping the designer personally! LOL

You might like to link this thread into the one member rodcastler brought your attention to.
Scroll to the top of page and copy the URL and paste it in a new post there, maybe with a wee mention about this thread. Don't use the first post link but the one higher up:
https://www.eevblog.com/forum/testgear/fluke-8060a-somewhat-functional/

In years to come as others are researching these DMM's it's helpful to have links to other threads.

[J-R]

Just to double-check, you're removing the barrel connector when trying it on battery?

A variable transformer would be great for running some AC tests.  For voltage, of course the setup should be self-explanatory, but for current I would use an incandescent light bulb in series with the Fluke as well as another known-good DMM.  You should be able to check all the ranges with that setup.

Some high voltage safety tips are make connections with the power switched off, only use one hand at a time, wear rubber-soled shoes....

[blue_lateral]

DONT put deoxit in the switches as someone suggested earlier. That is a mistake. I did that once many years ago. It's apparently too conductive for the high-Z circuitry. It is very hard to get rid of. Several washings with isopropyl did eventually make the meter functional again.

The "old fluke multimeters" thread referenced in rodcastler's post is the one you want.

[AVGresponding]

DONT put deoxit in the switches as someone suggested earlier. That is a mistake. I did that once many years ago. It's apparently too conductive for the high-Z circuitry. It is very hard to get rid of. Several washings with isopropyl did eventually make the meter functional again.

The "old fluke multimeters" thread referenced in rodcastler's post is the one you want.

Good to know!

I made some progress. Battery clip was bad. Loose rivet. I replaced it thinking that was the problem, but no dice. I'm still suspecting the switch in the side power jack. I cleaned all the switches and that helped. Ohms (all settings) now working and I'm getting reasonable readings. DC readings are now working on the 200mv and 2v positions. 20/200/1000 not working see the picture. I seem to remember seeing something about that in the troubleshooting section. It sounds like this is a common problem. If anyone has some suggestions please let me know. As I said, I'm unfamiliar with the "design language" used in test equipment, so when I look at the schematic it can be a bit puzzling. I'm guessing by the time I'm done I'll have a much better idea of what it is about. And, it doesn't help that I'm somewhat dyslexic LOL! Whenever there are a lot of switches and parallel wires on a schematic it's somewhat problematic for me. I can work through it, but it takes some time.

Also I have some broken buttons. two of the tan ones. The plastic must be brittle and I'll have to glue them in place or something.

I'm not sure how to test the AC functions. All I can think of is to use a variac with a current limiting resistor, and maybe making a voltage divider with some resistors??? I'm pretty unsure there and I really don't like playing around with line voltage. So if anyone has an idea that would be great.

I'm pretty encouraged at this point. After doing a close inspection, the meter is in excellent condition considering it's age. The caps all look good and there's no leakage or corrosion that I can see. I'm planning on replacing all of them as soon as I get things a little more under control.

I'll see if I can the readings from the test points tomorrow, for some more clues. I just ran out of time today. Thanks again for the help!
C-

PP3 battery clips are an abomination, no surprise this was one of the problems.

The buttons can be 3D printed, if you have a printer, and it's a safe bet there's the models for it on thingiverse (I got the model for the battery door for mine from there), or here: https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/

You might be better using an old-school function generator for AC tests, as one of the reasons the 8060 is so beloved is its very wide TRMS bandwidth, 100kHz iirc. Realistically for a full calibration you need quite expensive gear, but for a sanity check, just comparing it in parallel with another decent meter should be good enough for hobby use.

The pics show it doesn't have the TRMS daughter board, so you'll have the full set of caps to do.

[vindoline]

Check the input protection MOVs. They look like little colored resistors in the bottom right of the PCB. I have found that if the meter is briefly overloaded (easy to imagine in a broadcast setting) they increase in resistance and cause all kinds of weird and wonderful accuracy problems.

By the way, this meter is far and away my favorite model. I have several. No autoranging is great! I don't know how people can stand that little delay when using “modern” meters. Good luck!

[vindoline]

PP3 battery clips are an abomination

Completely agree! And Fluke seems to have used cheaper ones than usual on the 8060A. I think I've had to replace them on every sample I've worked on.

[Christine1953]

Hello Everyone! I think I'm struggling more with learning the SMF Forum software an I am with the meter I'm working on LOL! Other groups I belong to don't use it. So my apologies in advance if I mess things up from time to time! I'm using the help section for guidance, but there is a small learning curve. Thank you for your understanding. C-

[Christine1953]

There's this thread that may help as well:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

Thanks! It's a long thread with lots of history, but I'll work through it. Maybe I need to ping the designer personally! LOL

You might like to link this thread into the one member rodcastler brought your attention to.
Scroll to the top of page and copy the URL and paste it in a new post there, maybe with a wee mention about this thread. Don't use the first post link but the one higher up:
https://www.eevblog.com/forum/testgear/fluke-8060a-somewhat-functional/

In years to come as others are researching these DMM's it's helpful to have links to other threads.

I think I see what you are asking me to do. Combine this thread with the other one so all the associated information is in one place for someone who is having the same problem? If that's correct, great idea. The small problem I have at the moment is I'm still getting used to the SMF Forum format used here and I'm pretty gimpy, although the more I use it, the more it's making sense. If you can help a bit, I'll do it. I'm just pretty unsure of how it's done. Thanks!

[Christine1953]

Check the input protection MOVs. They look like little colored resistors in the bottom right of the PCB. I have found that if the meter is briefly overloaded (easy to imagine in a broadcast setting) they increase in resistance and cause all kinds of weird and wonderful accuracy problems.

Are these guys the ones you're talking about in the protection circuit? I think I read something about when you're on the 200mv or 2v settings this circuit is bypassed??? Could we just jumper around the protection circuit to test? As I said in my last post, both the 200mv, and 2v sections are working correctly, at least with DC. As for checking the MOV's if they're good/bad, I'd have no idea how to do that.

To be honest, I've suspected something might be amiss here, as I remember another tech telling me the meter stopped working while he was poking around in the high voltage section of a CRT monitor.  The DOA part came right after as we were trying to figure out what happened to the meter. It just completely quit working. My guess it was two unrelated problems. Let me know your thoughts. Thanks!

[Christine1953]

DON'T put deoxit in the switches as someone suggested earlier. That is a mistake. I did that once many years ago. It's apparently too conductive for the high-Z circuitry. It is very hard to get rid of. Several washings with isopropyl did eventually make the meter functional again.

Oopsie, That's exactly what I did. The switches do slide nicely now however! One more thing to do I guess. How do I clean it? Do I just dunk the whole main board in some solvent? I have lots of them around. CRC switch cleaner, Freon, Naptha, Acetone, and I have a bottle of Everclear. It's probably better for making martini's but it's pure grain ethanol.

[Christine1953]

Just to double-check, you're removing the barrel connector when trying it on battery?

A variable transformer would be great for running some AC tests.  For voltage, of course the setup should be self-explanatory, but for current I would use an incandescent light bulb in series with the Fluke as well as another known-good DMM.  You should be able to check all the ranges with that setup.

Some high voltage safety tips are make connections with the power switched off, only use one hand at a time, wear rubber-soled shoes....

Yes the barrel is not in the socket. Could I just jumper across the switch? I'd never use an external supply anyway. BTW that power jack looks like another one of those 29 cent parts...

Great ideas. For the lower voltage tests I was thinking a simple voltage divider, just so I have a little better control on the variac.
As for the current, I like the bulb idea, but should I use a current limiting resistor in line with the bulb for the lower current tests? I seem to remember something about a bulb not having much resistance until its glowing. Measuring current is not my long suit by any means. Thanks for the tip!

[Christine1953]

[/quote]The buttons can be 3D printed, if you have a printer, and it's a safe bet there's the models for it on thingiverse (I got the model for the battery door for mine from there), or here: https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/

You might be better using an old-school function generator for AC tests, as one of the reasons the 8060 is so beloved is its very wide TRMS bandwidth, 100kHz iirc. Realistically for a full calibration you need quite expensive gear, but for a sanity check, just comparing it in parallel with another decent meter should be good enough for hobby use.

The pics show it doesn't have the TRMS daughter board, so you'll have the full set of caps to do.[/color][/font][/b]
[/quote]

I don't know anyone around here with a function generator. (I live out in the middle of nowhere) LOL! If I can get this working, I'd be willing to send it out for calibration. (If anyone still does that on these old devices).

3D printing. I'll have to farm that out. The buttons are OK for right now.

Does anyone know of a BOM with part numbers from Digikey or another vendor for the capacitors used in this unit? That would save me a heck of a lot of time if one's available. Thanks!

One other maybe/maybe not important question. Do I need a ESD mat for the work I'm doing here? I use a wrist strap, but I don't own a mat. I work on mostly audio gear which doesn't need one. Thanks!

[Christine1953]

OK all I'm doing today is trying to get this stupid battery connection thing straightend out, and spending some more study time with the user manual. Then at 5PM, it's cocktail hour! Thanks everybody for the help. I'm feeling the love! Have a great weekend if you don't hear from me!
Christine-

[Christine1953]

My first thought is check the 1K fusible resistor R2.

I forgot to mention this. R1 and 2 are both good. Thanks!