On 3 Feb, 14:14, PeterD wrote:
Hell, grab an extension cord, plug it in, and go for it!

And then if it doesn't work look for lithium batteries maintaining the
calibration memory.

My HP 54542A digital 'scope died that way. No error message. It just
wouldn't start up.

After replacing the lithium battery and going through the self test
and calibration procedure it was fine.

Another potential problem is failing eproms. I bought a vector
network analyzer from ebay which turned out to have one flipped eprom
bit. I wrote this up on sci.electronics.repair.

The most common problem is probably dried up electrolytic capacitors
in switching power supplies. A cheap esr meter is worth its weight in
gold as there is often no visible sign of failure. I use a Peak
ESR60.

John