开云体育

Thanks Bob and Chuck. Unfortunately my 576 has a brown HV transformer, I
just looked.

I also checked C759 in the 5v power supply and I replaced it a few years
ago. My repair log shows how I adapted a more modern capacitor to the metal
can mounting if anyone is interested.

I continued with the Performance/Calibration steps without adjusting
anything. When I got to p5-13 step 14 I could not see the display shown in
Fig5-6 and realized this procedure was not going to be of any further help.

I set the switches to look at an NPN 2N3565 at low current and curves
flashed occasionally on the screen. Turning the Number of Steps knob and
tapping it changed the steps but did not fix the problem. I took to tapping
inside with an insulated rod and found U22 on the Step Gen board was really
sensitive. Re-seating it in the (cheap) socket fixed the problem and now I
get rock solid curves from 1 to 10 as selected.

It has been running for over an hour without problems but I am concerned
about the HV transformer.

Are these HV transformers available anywhere?

If it fails completely should I be looking at the newer 577? I saw someone
started a thread about a comparison but it went nowhere. Is the 577 better
than the 576?



Now I still have the problem with the TDS 644A power supply on the other
thread. I would love to hear comments on this one. Is there a parts list
available that shows the correct transistor for the standby power supply?
Why would a standby power supply run off 408V?

I see there are good comments from Siggi. I will reply on that thread.