Author Topic: Fluke 8060A - Refurbish questions  (Read 16550 times)

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Offline mbear2kTopic starter

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Fluke 8060A - Refurbish questions
« on: September 07, 2016, 11:11:29 pm »
I picked up a very nice (and inexpensive) 8060a today and am finding a few issues to work.  I've read all the great posts regarding general overhaul - and I intend to do the caps and clean the display connectors,etc.

The meter fires up, self tests and 4 out of 5 times I get a good strong display.  Once in a while the display is missing segments, or goes blank.  I measured the battery and it was around 9v.  I was poking around seeing if there was any consistency to the display and re-measured the battery - and it was at 8.4 v.   I measured the current and the meter is drawing 25mA once 'booted'.  That seems excessive and I'm expecting is due to a very leaky cap.

I pulled it apart and the caps have not visually leaked (that I can see) and the elastomeric pad looks okay on the display board.  I have not pulled the LCD off yet.

I thought I'd throw it out there in case there is something else I should be looking at with regards to current draw - maybe what I should expect to see for current.  And maybe also plan to order while making my parts list.

Thanks 
 

Online Andy Watson

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Re: Fluke 8060A - Refurbish questions
« Reply #1 on: September 08, 2016, 12:45:22 am »
I don't know about the current consumption issue, but with regard to the display:- I've had a peek inside my 8060 and it appears to use the same construction as the 8020 with regard to the connection of the LCD. The display is connected to the PCB by a zebra strip(s). In the 8020 the zebra strip is located by a plastic housing but should be free to move within the housing. I found that the zebra strip was stuck to its housing - which prevented it from making a secure contact with the PCB. I don't know what was causing it to stick - possibly contamination, or possibly a plasticiser leaching-out from one of the components. Carefully tease the zebra strip away from the plastic housing, even more carefully tease it away from the LCD, clean all the stickiness away with IPA and re-assemble. 
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #2 on: September 08, 2016, 01:08:03 am »
Ah - good point.  I only checked/cleaned the display board elastomeric/zebra-stripe edge, but did not look at the plastic 'surround'.  Will do so when I take it back off to also clean the LCD connector.

Also my SN is: 3220695.  Not sure this matters, but wanted to share in case it helps date the meter.
 

Offline retiredcaps

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Re: Fluke 8060A - Refurbish questions
« Reply #3 on: September 08, 2016, 03:25:28 am »
I measured the current and the meter is drawing 25mA once 'booted'.
The Fluke 8060A has 200 hour battery life.  Assuming a 500mAh 9V battery, normal draw should be 500/200 = 2.5mA.  If 25mA were normal, the 8060A would only last 20 hours.

Quote
I pulled it apart and the caps have not visually leaked (that I can see
The caps on the Fluke 8060A always seem to leak at the bottom bung.  Thus you will never see a bad cap by looking at the top.  There is likely a 50% chance or better your caps are bad.

Modemhead's blog 8060A entry should give you some hints.

http://mrmodemhead.com/blog/fluke-8060a-repair/

edit: removed the h from the mA.
« Last Edit: September 08, 2016, 04:56:25 pm by retiredcaps »
 

Offline ModemHead

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Re: Fluke 8060A - Refurbish questions
« Reply #4 on: September 08, 2016, 12:49:36 pm »
The current draw does sound excessive. I would check mine for you but I'm away from home right now.

I recently aquired a non-working IBM-branded 8060A/AA.  At first glance it looked OK, but actually all of the caps had leaked except for the one in the RMS converter section.  The leakage had destroyed one of the 40-pin socket pins and the 7660 had failed.  Cleaned up the mess, replaced the parts and the socket, and now it works great.
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #5 on: September 08, 2016, 03:15:10 pm »
ModemHead - Thanks - I have read your posting/blog on the topic several times.  Great help.  With the display board removed, it all looks clean as a whistle.  But until I remove each cap, I won't know for sure.  All caps are ordered, and I included the ICL7660, 40 pin and 8 pin sockets (just in case).

retiredcaps:
"The Fluke 8060A has 200 hour battery life.  Assuming a 500mAh 9V battery, normal draw should be 500/200 = 2.5mAh.  If 25mAh were normal, the 8060A would only last 20 hours."

I hadn't thought of 'reverse engineering' the battery life from the published specs...  much appreciated.
 

Offline retiredcaps

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Re: Fluke 8060A - Refurbish questions
« Reply #6 on: September 08, 2016, 04:54:08 pm »
The current draw is documented in this blog

http://mrmodemhead.com/blog/a-very-unique-fluke-8060a/

"Dmitri reports an average segment current of about 10uA, and the entire unit still only draws 2.3mA from the 9V battery with an all-zero display in VDC mode, 3.8mA in VAC mode."
 

Offline retiredcaps

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Re: Fluke 8060A - Refurbish questions
« Reply #7 on: September 08, 2016, 06:33:37 pm »
The Fluke 8060A has 200 hour battery life.
The stated life in the manual for the 8060A is 170 hours. I got it mixed up with another Fluke meter from that era (the 8020A is 200 hours).  Oops.

So 500/170 = 2.94mA roughly.
« Last Edit: September 08, 2016, 10:59:14 pm by retiredcaps »
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #8 on: September 08, 2016, 10:37:47 pm »
Thanks - I had just looked that up and saw the 170 hours as well.

I did a quick test of my -5v using an external power supply at 9.3v, and get -3.4v.  Popped out my first cap while waiting for parts... Hopefully will save this one just in time!




 

Offline retiredcaps

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Re: Fluke 8060A - Refurbish questions
« Reply #9 on: September 08, 2016, 10:58:07 pm »
Popped out my first cap while waiting for parts...
Yep, not surprising.  As I mentioned, these caps all leak from the bottom so a look at the top may lull you into a false sense of security.  I can't remember which thread, but someone didn't believe me and decided his caps were okay since they were all flat top.

In modemhead's blog, there was a comment from Mr Lowe on Sept 7 (yesterday) about finding leaky caps as well.

Don't forget to clean up the pcb with 91% IPA after you remove all the caps.
 

Offline ModemHead

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Re: Fluke 8060A - Refurbish questions
« Reply #10 on: September 08, 2016, 11:09:08 pm »
Those pics look very familiar. The most insidious thing is that the leaked electrolyte seems to wick  right up the legs of other components and do damage.
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #11 on: September 09, 2016, 12:14:38 am »
Is it okay to use a flux remover chemical (FluX-Off)?  IE, on a cotton tip and just around the newly soldered pads?  Also, the alcohol cleans the pads a bit, but not enough I'm comfortable with making a good solder joint.

So far no wicking damage I can see - just some cleanup you can see in the pix.

More pix:

Just for fun... I'd expect 2-8uA leakage per uf - maybe 200-800uA?  Any one of them are between 1.3 and 1.9mA.


ESR is a little high...


More physically leaking caps.


A shot of the project (including my static strap).






 
 

Offline ModemHead

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Re: Fluke 8060A - Refurbish questions
« Reply #12 on: September 09, 2016, 12:46:40 am »
I can't advise one way or the other on using chemicals, since I tend to use just IPA and mechanical action. To brighten the copper I use a fiberglass scratch brush.  Also use a disposable "acid brush" with the bristles cut down to get some scrubbing action while the board is sitting in about a 1/4" of IPA.
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #13 on: September 09, 2016, 01:11:28 am »
So no issue soaking the entire board?  1/4" I assume to stay clear of the switches?

I have a fiberglass scratch brush and the acid brushes, so good to go there.
 

Offline ModemHead

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Re: Fluke 8060A - Refurbish questions
« Reply #14 on: September 09, 2016, 01:49:41 am »
So no issue soaking the entire board?  1/4" I assume to stay clear of the switches?7

I used to be sqeamish about that, but no more, it's the best way to float away the contaminants.  @drtaylor advised not to immerse the switches, but they stand off the board quite a bit, so 1/4" works pretty well.  I use some canned air to dry out the piezo, then leave it in front of a fan for a while to dry.  On my last repair, I think I did it three times, the final time was to clean the flux from all the soldering.

BTW, this procedure can often do wonders for those units that won't quite zero out.

Edit: just to be clear, the daughter board and elastomeric strips are not involved in the "bath".
« Last Edit: September 09, 2016, 01:53:22 am by ModemHead »
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #15 on: September 09, 2016, 02:01:49 am »
Got it - the piezo was the other component I was concerned with.  I'm not too squeamish.  In the late 70's, I worked for a company that engineered custom circuit boards and flow soldered them in small batches.  They'd be bathed in trichloroethylene (glad that wasn't my job) and then we'd take the stuffed boards and load them in to an actual household dishwasher.  Stack the boards like plates and let it rip (water only).

Ok - think I'm good for the moment - until my parts arrive.  Thanks!
 

Online tautech

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Re: Fluke 8060A - Refurbish questions
« Reply #16 on: September 09, 2016, 07:47:58 am »
I picked up a very nice (and inexpensive) 8060a today and am finding a few issues to work.  I've read all the great posts regarding general overhaul - and I intend to do the caps and clean the display connectors,etc......
Just in case you've not seen this thread by one of the 8060 designers:
https://www.eevblog.com/forum/testgear/old-fluke-multimeters/
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #17 on: September 09, 2016, 11:10:28 am »
Yes - that was a great read.  We should rally engineers from these growth periods to write more.  I'd love a book on the inner-workings of the teams, designs, challenges, politics, competition - but focused on test equipment, or vintage audio, TV's, etc.
 

Offline retiredcaps

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Re: Fluke 8060A - Refurbish questions
« Reply #18 on: September 09, 2016, 04:09:19 pm »
I'd love a book on the inner-workings of the teams, designs, challenges, politics, competition - but focused on test equipment, or vintage audio, TV's, etc.
Some of the above topics were discussed on the amphour interview with drtaylor.

http://www.theamphour.com/180-an-interview-with-dave-taylor-multi-talented-meter-maker/
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #19 on: September 09, 2016, 04:10:49 pm »
Yes it was - I just want more!   :)
 

Offline retiredcaps

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Re: Fluke 8060A - Refurbish questions
« Reply #20 on: September 09, 2016, 04:14:16 pm »
I used to read those type of books, but haven't in a while, but things like

The HP Way: How Bill Hewlett and I Built Our Company

might be of interest to you?
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #21 on: September 09, 2016, 10:32:05 pm »
Great suggestion.  And I just found a used hard-cover copy for $4 delivered.  Done!
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #22 on: September 10, 2016, 08:49:22 pm »
My parts arrived today.  Finished cleaning the leakage areas, overall cleaning and popped in the caps.  My one initial reference point -5v is now right on the money.  That's all I've had time to test, but looking promising.  More testing yet to do...

One note; there is an extra 100uf cap in my meter.  So there are a total of five 100uf caps for this meter (date code of the couple of chips I checked appears to be 1983).  This is not shown/referenced in the manual I have.  I have not traced it out, but seems to be in the area of the "SC7714 Fluke RMS" chip.

More to come later with some more pics.
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #23 on: September 11, 2016, 01:11:59 am »
Ok - all test voltages look good.  The meter is now drawing 2.3mA from a 9v battery.  And initial DC volts and ohms measurements look spot on.

The only remaining issue is that the display flickers a little - and comes on rock solid is I press/shift the display a tiny bit.  That leads me to believe the elastomeric connections still aren't good.

In removing the display assembly, I cleaned the connectors at both ends early on.  Now I know there's the connector within the display assembly but am looking for some guidance on pulling that apart.  Any thoughts?

Thanks
 

Offline mbear2kTopic starter

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Re: Fluke 8060A - Refurbish questions
« Reply #24 on: September 11, 2016, 03:21:15 am »
Alright - I have the LCD disassembly figured out.  It was in the manual that came with the meter!  And the schematic, drawings and parts list includes the additional 100uf cap I mentioned above.  The manual I printed on nice big paper is an earlier version...

On to the next issue.  I cleaned the LCD interconnect pins on the PCB, removing the actual interconnect (#7 in drawing) with tweezers and not touching it.  The issue now is reassembly.  The interconnect is I believe supposed to rest flat in the channel so the LCD can be snapped back in to place.  As you can see below, either the interconnect has grown, or the plastic shrunk?  It will not lay flat.  What's the trick here?



 


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