"eBay test gear lot", part 1: Keithley 191

[Bendba]

Hi,

As some may know, I recently purchased this massive lot of aviation test gears from eBay: http://www.ebay.com.au/itm/263014645608

I'll be sharing some details about most of them as I get to identify, test, fix, use or scrap them. So, many old gears tear downs to come.

The first one on the list is a Keithley 191 bench DMM, with AC option installed.

I was really hoping this one would "plug and play" but not quite. As I plugged it in and turned it on, it blinks, alternating between 1. (as in the photo) and -0.00000
Which, according to the notes on the case means overload.
But nothing is connected to it.
It doesn't read anything in any of the ranges of any function.
I left it on for a while as I thought maybe something was temperature sensitive, but no improvement. After a few minutes, the display just blanked.

So, some troubleshooting to do there. I downloaded the manual and I am investigating, praying that it's not a damage ROM.

Here are a few photos of the meter.







PS: Please, let me know if another section of the forum would be more appropriate for those ancient test gears discussions.