Fluke 8060A - Refurbish questions

[mbear2k]

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 

[Andy Watson]

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. 

[mbear2k]

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.

[retiredcaps]

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.

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.

[ModemHead]

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.

[mbear2k]

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.

[retiredcaps]

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."

[retiredcaps]

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.

[mbear2k]

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!

[retiredcaps]

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.

[ModemHead]

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.

[mbear2k]

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).






 

[ModemHead]

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.

[mbear2k]

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.

[ModemHead]

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".

[mbear2k]

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!

[tautech]

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/

[mbear2k]

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.

[retiredcaps]

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/

[mbear2k]

Yes it was - I just want more!   

[retiredcaps]

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?

[mbear2k]

Great suggestion.  And I just found a used hard-cover copy for $4 delivered.  Done!

[mbear2k]

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.

[mbear2k]

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

[mbear2k]

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?

[retiredcaps]

As you can see below, either the interconnect has grown, or the plastic shrunk?  It will not lay flat.  What's the trick here?

I have never disassembled it that far so I don't know.  I think modemhead is home on Sunday so he might be able to give some feedback.

Excavatoree is the only other person that I know of that might have disassembled the meter to that level.

[ModemHead]

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?

No trick, it's supposed to fit nicely, as shown.  The later models have rectangular strips instead of the round ones.  The only problem I've noticed with these round ones is some flattening, so that I had to try rotating the strip a bit until finding the sweet spot where it made best contact.

This reminds me of an internet discussion about Beckman meters where someone suggested soaking the elastomeric strips in water to get them to swell up, and make better contact.  So, warm air to dry it out maybe?

[mbear2k]

Thanks ModemHead.  My shop space has been very humid.  Maybe let it dry out as you mention.  Mine is slightly oblong, so once I get the fit, I'll try rotating as well.

And if I'm reading the manual correctly, I hook the aligned LCD assembly on the left side then press down on the right to snap under the tab.

One more question - I have not separated the lens, gasket or polarizer.  Should I leave well enough alone, or is there recommended cleaning of some kind for these?

[ModemHead]

And if I'm reading the manual correctly, I hook the aligned LCD assembly on the left side then press down on the right to snap under the tab.

Yep, that usually works best.  I hold my breath for the "snapping" part, because that old plastic can be brittle. You can see a crack in the screw post on mine above.

One more question - I have not separated the lens, gasket or polarizer.  Should I leave well enough alone, or is there recommended cleaning of some kind for these?

I'm surprised it did not fall apart, never had those components stick together.  But if it's clean and no FOD, then I suppose there's no need to mess with it.  BTW, only the oldest models have the separate polarizer.  Later ones have a more modern LCD with the top polarizer built-in.

[mbear2k]

Yes - my concern as well as one of my screw posts has a crack as well...

My LCD assembly was all loose.  In fact I'm trying not to slide the pieces around too much to avoid scratches.  I did pull the lens and polished it with Novus.  Looks great.

Ok - so working on shrinking the interconnect.  Will report back.

[mbear2k]

Well - had a catastrophe here.  I was able to get the interconnect to shrink by chilling it in the fridge.  Fit perfect.  However, at the snapping in of the LCD part, the LCD cracked. It was going so well - has it all lined up and got the LCD and gasket below the tab, gave it one last gentle push to get the lens in place and the LCD cracked.

So - closing this one out until I find a parts unit.  Thanks for all the help! 

[ModemHead]

Oh no!  I could have prevented this, I'm now sorry for not adding this information to the thread.  Some time after this morning's posting activity, I went to put mine back together after the photo. I realized at that point that it was better to "slide" the LCD glass part in under the tabs, then "snap" the rest of the stuff (lens, gasket, polarizer).

Well here's a somewhat amusing story that you may yet come to appreciate.  I did not mention that this last IBM-branded unit that I fixed had a bad LCD. Back polarizer is shot, plus there is the "bleeding" effect inside the glass sandwich. So I monitored eBay for months looking for a wrecked 8060A with a decent-looking LCD.  Finally scored one for $20, shipped.  When I got it, it turned out to work perfectly, and is a much newer unit than the other couple that I had. The case even cleaned up like-new.  So instead of the parts mule I needed, I ended up with another working meter that I did not want to part out. So instead I robbed an older unit with an uglier exterior of it's LCD and finished restoring the IBM unit.

This has happened to me for other things, I look for a parts unit and end up with an easier repair than the one I was working on.  So I hope you can find an LCD...

Edit: accidentally a word

Edit #2: The refurb job I mentioned above is now documented in a blog post.

[Don Hills]

... However, at the snapping in of the LCD part, the LCD cracked. It was going so well - has it all lined up and got the LCD and gasket below the tab, gave it one last gentle push to get the lens in place and the LCD cracked.
 ...

I feel your pain. I once managed to destroy the LCD in a mint HP 100LX by mishandling. Now, how do I say this in the nicest possible way? You should have RTFM.

The picture in the manual that you posted yesterday (post 24) shows that you slide the LCD in then snap the rest in.

(Following this thread because I have an 8060A/AA that still works OK.)

[vindoline]

Well - had a catastrophe here.  I was able to get the interconnect to shrink by chilling it in the fridge.  Fit perfect.  However, at the snapping in of the LCD part, the LCD cracked. It was going so well - has it all lined up and got the LCD and gasket below the tab, gave it one last gentle push to get the lens in place and the LCD cracked.

So - closing this one out until I find a parts unit.  Thanks for all the help!

I may have an LCD assembly I can send you. I just moved though, and the lab is in a state of "flux!" Send me a PM if you're interested.

-John

[mbear2k]

Very nice of you to offer John - I will send you a PM.

I have a couple of spare voltage converters (ICL7660CPAZ-ND) if anyone needs one.

Mark

[mbear2k]

Very happy ending!  John (vindoline) was kind enough to send me a display and all is working well!

Thanks to John and all that assisted!

[vindoline]

Very happy ending!  John (vindoline) was kind enough to send me a display and all is working well!

Thanks to John and all that assisted!

Outstanding! I'm glad I could help and I hope you enjoy the meter as much as I do.

[ModemHead]

 

[ogdento]

I know this is an ancient thread but with all the lcd assemblies that have been scavenged for their display glass, are there any extra micro boards and/or mainboard-to-micro elastomeric strips kicking around?

After seeing Dmitri's awesome LED mod on Modemhead's site, I'm considering an OLED mod... I have an 8060a with an early-style lcd (no built-in polarizer) and it's OK but not great - there's no bleeding but some segments aren't 100% solid... there's almost specs of missing fluid if that makes sense.  Fwiw, I got this unit doa with a blown-short vr3 and puked caps... I re-capped it, replaced vr3 and the mac socket and everything has been lathered/rinsed/repeated many times in IPA.

My OLED plan is to solder wires to the lcd pads of the micro board, sample the output and translate it to a small OLED.  I think it'll be a fun project but since my unit works fairly well I don't want to mess with my only micro board.  The mainboard-to-micro strip is wonky too (unit hangs a lot) so unless I can find another I'm going to solder a pluggable header onto the mainboard and junk the elastomer (thanks to Dr Taylor for using .1 pitch!)

Anyway, I can't find anything for sale on the usual sites so I figured it wouldn't hurt to ask here - I've got some parts I could trade too.  Cheers!

[vindoline]

Ogdento, is this the part you need? I don't have  the zebra strip, but it should be easy to fit a generic replacement if you want - or just go with the mod you proposed.
Send me a PM if you're interested.

[Fungus]

are there any extra elastomeric strips kicking around?

You can probably use generic ones. All you need is the correct height, you can easily cut them to the right width.

[ogdento]

vindoline, that's exactly what i'm looking for!  pm sent

and great point about generics.  I couldn't find any at digikey or mouser but I've found a catalog from Fujipoly who makes the Zebra brand strips.  There's also a bunch of parts on the usual Chinese supply sites so I'll dig through some of those.

I found a $4 Cypress psoc arm m0 kit in a drawer... it's overkill for use as the oled adapter but i had it handy and am itching to get started.

[ogdento]

Wow, thanks to John for the extra micro board and associated bits.  I got the parts yesterday and on a whim I threw my lcd on it, using my mainboard-to-micro elastomer (after 6 or 7 cleanings) and the lcd elastomer from John... the darned thing worked! 

The display isn't 100% perfect so I'm still going forward with an OLED swap, but it's 100% usable and I'm able to revert it to "stock" if I want to.

[vindoline]

Wow, thanks to John for the extra micro board and associated bits.  I got the parts yesterday and on a whim I threw my lcd on it, using my mainboard-to-micro elastomer (after 6 or 7 cleanings) and the lcd elastomer from John... the darned thing worked! 

The display isn't 100% perfect so I'm still going forward with an OLED swap, but it's 100% usable and I'm able to revert it to "stock" if I want to.

You're welcome    Now it's a bit less daunting to go for the OLED mod! I'm looking forward to seeing how it comes out.

[OH2LIY]

I just opened my trusty Fluke, probably third time to check capasitors. Meter is made 1987 or 1988 and capasitors have 8611 markings (11/1986?). What I look under capasitors and checked randomly couple capasitor capasitance&esr, I don't see any reason to change them, everything looks to be ok (after 32 years)?

[retiredcaps]

What I look under capasitors

When you look under, are you physically removing them to do a visual inspection and test with the ESR meter?

Most of the problems with the 8060A are the caps go bad and leak from the bung (bottom) and not obviously visible to the naked eye until you remove them.

[ogdento]

+1 to Retiredcaps... the last two 8060a meters I re-capped looked great until I pulled the caps out... only then did I see that they had indeed puked their guts onto the pcb.  One was an 86 and I think the other was from 91.  I had to replace the MAC socket on both as well.

[ogdento]

Update on my OLED mod... wired up this nifty adapter so I could sample the lcd output and drive an OLED, but I've apparently screwed something up.  On another 8060 with the LCD removed, I see a 40kHz output at TP9 - but I don't get that with this adapter. 

Not sure what I've done - maybe I broke the board when I soldered the wires on, but I use an anti-static strap and I've never damaged a CMOS chip before.