9100Bs freshly acquired, weird variations

[teenix]

(02-27-2019 05:29 AM)tubenewb Wrote:  

(02-27-2019 05:26 AM)dramsey Wrote:  Bear in mind the little CRTs in the 9100s will take some time to warm up enough to display an image...

Well, I plugged it in and it did nothing but hum (from the power supply). I did, amazingly, run into someone who was trying to get this particular unit working years ago. They were having trouble with the replacement of a germanium diode (?) on one of the power supply boards. I see the replacement but it didn't work, apparently. That's where they left it, over a decade ago.

Probably wise to be careful poking around in there too. The cathode ray tube operates from very high voltage (around 3500V), not to mention the mains power. Both will be nasty to the unwary. Some capacitors may remain charged at a high voltage even after power off.

cheers

Tony