I just started work on my 8060A restoration project. I have the 8060s from the eBay auction and a few of my own to fix up. My lab is all set up for a production line operation for 15 8060s and one 8062. I'm keeping notes on each one, condition, functional, rev of the assembly and PCB. Several were fully functional. A few just need their LCD connections cleaned. A few turned on but have obvious problems. Only 1 was completely DOA. Only 1 had plating on the LCD, but it was the 8062. Regardless if they were fully functional, I am recapping all of them. I am also cleaning the two elastomeric connectors, the carbon one for the LCD, and the silver filled one that connects the SM4 to the MAC. Also cleaning the PCB patterns that contact the elastomerics.
My process is to take them all apart. Remove the uC assembly. Remove all the loose plastic parts. Then using my $5 Pace MTM100 (Auction at my former company...what a great thing to have), I'm removing all the electrolytic caps. Most came out easily with a application of flux then using the hollow sucking head of the Pace rework station. The ones that were corroded gave more problems, but I managed to get them out with not too much damage. I used all the tricks of the trade, solder sucker (Edsyn), solder wick, and so on. I've gotten through 9 so far.
After the caps are out, I cleaned the boards thoroughly with 99.9% IPA and an acid brush. Then soaked the whole PCA in a glass tray with clean IPA. Then another acid brush scrub and blowing out the IPA with a low heat air gun. Then I put the cleaned assembly aside to dry for a few more hours. I've only recapped three so far for testing. They got a similar cleaning process after the new caps were put in.
As far as the replacement caps, I've decided to use Polymer Aluminums. These have the advantage of lower ESR and higher ripple current (not really necessary for the 8060), but best of all, due to the organic polymer, they will not spew electrolyte. These 8060s should last for another 30 years. I only had one value I could not fit physically in the position. So I went with the Nichicon UTT for the 22uF/16V part. All the rest are Nichicon RS, RNS or RNU types.
All these parts are in stock at Mouser. These all fit the physical diameter, height, and lead pitch of the 8060A PCB. They do have much higher leakage current on paper, but in practice and at the voltages used, the effect on battery life should be minimal. I've got three units recapped now and ready for testing. I will publish the list later after I'm sure there is no ill effect from the added leakage current. But I do think that will not matter. I'm actually hoping the RMS noise floor will be improved with the new 7660 caps.
I've contacted an old friend at Fluke to see if I can use a calibrator so I can tweak them in. I can calibrate the DC ranges with what I have, but I do not have an accurate AC source at 10kHz which is required to trim the AC freq flatness. There's a real possibility that Fluke has policies against this, but my friend is actually the marketing manager for the Calibration group. SO I'm crossing my fingers on that. If I'm unable to trim the AC, I will let prospective buyers know.
In a side note, one of my 8060s is really a prototype unit. It has a ceramic MAC chip, the RMS converter in a socket, and it has several kludges. The constant current output uses a LM334 and a couple of bodged resistors. There's also a couple of jumpers. This very likely is the oldest 8060 around as it is clear I was still fooling with it. My IBM version 8060A also is an early version, with two jumpers, but it has worked well for years. Most of the eBay units were mid to late 80s with a board rev of H and an assembly rev of H. Some were labeled Rev H-1. No idea what the difference was. I did not get any of the late production units that subbed the Analog Device TRMS chip on a daughter board. All have the Fluke designed Motorola BiFet TRMS converters.
I'm done with my G-Job for now, so I hope to finish these up in a couple of weeks. I'll report progress soon.