My new (used) Fluke 77 Series IV DMM

[LDSisHere]

Re: My new (used) Fluke 77 Series IV DMM

Use a 3.000V DC source for calibration. I find that the green pin on some ATX power supplies is close to 3.000V. Have the other calibrated meter plugged in at the same time so both read the same value.

See my example of calibrating a Fluke 77 II

http://www.eevblog.com/forum/general...254/#msg152254

Good news for me. I was able to take my Fluke 77 to work and compare it to the calibrated Fluke 179 and it was the same readings on both. I used a 1.5V battery so I was getting readings down to mV on the comparison then I used a 9V battery afterwards. I used my 77 to calibrate my 21 and it seems to be good now. I was also able to get the peak hold mod done while I was calibrating it and that also seems to work.

I have purchased 3 used 20+ year old Fluke 70 series style multimeters and all have been within spec (0.3% + 1 digit) in the DCV range. The 77 II that I cleaned up with was the "worst" at 4mV off, but still within specifications.

If your Fluke 21 is the one that is off, that is the worst drift I have personally seen in an older Fluke.

I did buy this meter used so someone else may have messed with the calibration or I may have messed with it myself so long ago that I do not remember it. It would not be the first time I have messed with something that I had no idea what it was supposed to do just to see if I could figure it out. This is a habit I still seem to have from time to time.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

I used my 77 to calibrate my 21 and it seems to be good now. I was also able to get the peak hold mod done while I was calibrating it and that also seems to work.

Excellent job on the DC V calibration and auto hold modification.

PS. The 3.000V DCV calibration recommendation comes directly from the Fluke service manual.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

BTW, the old 70 series multimeters will run up to 2,000 hours on a 9V battery.

So I put new batteries into my smoke detectors annually and use the old ones inside my multimeters.

The Fluke 77 IV/179 runs up to 400 hours on a 9V (assuming no backlight).

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

@LDSisHere, I can't tell from your first photo, but I recently bought an used Fluke 77 IV and ran into something similar to what ModemHead posted at

http://mrmodemhead.com/blog/fluke-77...per-corrosion/

You might want to check yours when you have a moment? To lift the pcb off the case, you have to remove the 440ma fuse to expose a screw underneath.

Hopefully, your pcb will be clean and pristine.

[LDSisHere]

Re: My new (used) Fluke 77 Series IV DMM

Thanks for pointing this out. After reading this post I tore into my meter at the first opportunity. There were two places on the back that had just a slight bit of "snow" and around the LED's there was just a trace amount that I could barely see. A Q-tip and 91% alcohol made quick work of the problem areas. I think I will check the board every time I have to change the battery at the minimum.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

There were two places on the back that had just a slight bit of "snow" and around the LED's there was just a trace amount that I could barely see.

I had the same problem areas around the LEDs.

[modemhead]

Re: My new (used) Fluke 77 Series IV DMM

I had the same problem areas around the LEDs.

I don't know why, but the backlight LEDs and the area around the piezo beeper seems to be a magnet for that white stuff.

[spectrum]

Re: My new (used) Fluke 77 Series IV DMM

Hi, I am writing from Italy. I had this multimeter 77IV (circuit board Fluke 17X) which does not work. In the display I can see only this sign "- - - -", no numbers. I see right all the measuring selection (VDC, VAC, mV ecc..), I can read "LEAD" when I am in the A selection, and at the start I can read 77-IV.
Someone knows which is the problem ? What are the components failed ?
Ciao. Stefano

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

In the display I can see only this sign "- - - -", no numbers.

Back in post #24, I provided a link to modemhead's blog entry and it may provide a clue ...

"The meter was non-functional with some digital-domain fault that caused it to always display “- – - -”. The trouble turned out to be a corroded via that was open from the top layer to the bottom, due to the plated-through hole being eroded away. A wire patch soldered in brought the 177 back to life."

PS. As my sig file suggests, clear focused pictures following my instructions exactly help us help you.

[spectrum]

Re: My new (used) Fluke 77 Series IV DMM

Thanks Retiredcaps, it is useful but I do not find corrosion in my Fluke, anyway I will check better.

[Kiriakos GR]

Re: My new (used) Fluke 77 Series IV DMM

but I do not find corrosion in my Fluke

There is nothing to find .. get another multimeter and do measurements so to confirm that all PCB lines are in good condition.

[spectrum]

Re: My new (used) Fluke 77 Series IV DMM

No sign of corrosion, PCB in very good condition, PCB lines I checked OK

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

I know you are discussing this over at modemhead's blog and that he is travelling right now.

Let me ask some questions.

1. Are you the original owner?
2. How did this --- problem start?
3. Was the meter subjected to high voltage or high current?
4. Did this meter work properly before?
5. Has this meter been dropped?
6. Is there any battery corrosion?

[spectrum]

Re: My new (used) Fluke 77 Series IV DMM

Thank you for the interest. Here the answers:
1) It was a multimeter that my company bought and used for some years
2) I do not know, it is happened not in my hands.
3) I think no, we do not have high voltage or current in our labs (but I cannot guarantee)
4) I think yes, I remember so.
5) I do not know but it has no damage and it is in very good condition
6) No sign of some corrosion, PCB clean and in very good condition.

[retiredcaps]

Re: My new (used) Fluke 77 Series IV DMM

1) It was a multimeter that my company bought and used for some years

Since the Fluke 77 IV is a current model, the lifetime warranty should apply if your company bought it from an authorized dealer and assuming the meter wasn't abused.

I would contact Fluke and explain the situation.

[Kiriakos GR]

Re: My new (used) Fluke 77 Series IV DMM

Fluke life time warranty were set at 7 years period before 2 years ago, and then some how they readjusted it again with a lower time period than that, so to support with those funds the R&D about new products.

I have stop following this confusing subject for some time.
They should make one chart with their product range and the warranty period for its one.
Or else every one who spend 40$ for Fluke 101 he will believe that he gets seven years warranty with it.

[spectrum]

Re: My new (used) Fluke 77 Series IV DMM

Here in Italy the Fluke service is not so sure.
Some co-workers tell me that they were charged for warranty repair and I can confirm this. I sent this meter and it has been returned with an estimate repair of 120-130 euro. I think this warranty lifetime seems a fake. anyway out of any convenience (a new 175 costs 199 euro).
We asked to Netherland Fluke if is there another service in Italy but no answers. In our company we are considering to buy Fluke no longer.