Not exactly a huge score, but after some uncertainty, I'm pleased with the Keithley 2000 I got on ebay for ~$250.
First impressions was that it was packed quite well. The VFD was bright, and the voltage readings off my Chinese AD584KH based voltage reference were quite close to the numbers on the references "calibration certificate." It was also a sickly beige
![Undecided :-\](https://www.eevblog.com/forum/Smileys/default/undecided.gif.pagespeed.ce.cCZ6w-jWpR.gif)
At first I thought it was from aging of the plastics, but when I opened it up, I was met with the smell of stale tobacco smoke. Fortunately, it hadn't accumulated enough to leave a visible film as it had on the outside. I also noticed that at some point the motherboard had been removed and then reassembled by a meathead. Cables to the front panel and power supply didn't take advantage of a clip intended for them on the side of the chassis. More concerning, the main PCB was flexed because they'd forced the front right corner in over the guide/support tabs on the chassis. In the process, they managed to scrape the solder mask off a grounding trace.
Once I'd reassembled the device properly, I ran the self-tests and was disappointed to see the failures cascading off the very first test, 100.1, which checks to see if the A/D converter's 0v reading is in range of the design specs. The repair manual wasn't very helpful (it doesn't identify the signals on the various test points, and doesn't even bother explaining how to get the device to display the measured value for each test (When you run the tests manually, in step mode, pausing after each test, you can hold down the shift key to see the measured value). I finally got fed up, found the reverse engineered schematic online, and started orienting myself to the signals on the A/D converter IC by probing each lead with my scope. As I shifting the device on my desk to get a better view of the leads on the side of chip closest to the right side of the chassis I noticed a bit of white. At first I thought it was silkscreen priting, but it seemed misoriented and out of place. I looked closer and it seemed to be a small fiber of some sort. I flicked it away with my gloved hand and then blew the area clear with some canned air.
All the tests passed! I'd like to blame the contamination on the meathead who did such a bad job reassembling the thing but there is a good chance that it was a stray piece of pet fluff from our dog. (Once again, I've managed to fix a piece of equipment simply by taking it apart, looking at it, and putting it back together).
From the date codes on some of the components and the date on the one and only calibration, it appears that my multimeter was manufactured in the latter half of 1995. Probably a good idea to replace the electrolytic caps at this point? I'm also going to try and clean up the outside more. Any tips on dealing with the tobacco stains on the rubber/silicone buttons?