The observant among you will have noticed the the HP 3476B DMM I posted a picture of on page 3476 wasn't on.
Tht's because it would not come on
It worked last time I had it out. It always had one fault, all the decimal places were on. This indicates a low battery but it lasted OK so I assumed (don't do that) it was the battery monitor circuit.
Anyway I investigated it yesterday. It quickly became apparent thet the rechargable battery was flat. Pack seems to be 4 2/3A cells. No leakage visible so I pulled it out and stuck it on the Pro-Peak charger.
Charger said NO!
A quick check on a bench upply in constant current showed about 2.2V at 1/2A. The penny dropped, it had two shorted cells. As we know this is caused by Cadmium crystals growing across the insulator. It's likely that one had been shorted since I had the meter, resulting in permanant low battery indication.
So I stuck it on a capacitor discharge rig and two pulses got it up to 3.4V. Several more got it above 4V. I put it on the Pro-Peak and it charged OK. Capacity check came out at about 600mA/h so not too shabby.
All fixed