On Wed, Mar 23, 2022 at 01:37 PM, Ozan wrote:
---
There were two issues. Even with opamp supply totally dead due to "B" side,
VR1724 should have kept base of Q1732 above ~56V if opamp were the only issue.
However, Q1732 base was at 26V. No matter what happens to opamp it can't pull
base below 56V without another fault. At the end CR1732 was also faulty. Both
+15V supply and CR1732 needed fixing for proper operation.
Ozan
There still are issues with the +15v at least.
Last night the readings were taken with the CR1751 and CR1732 disconnected.
This morning, I tested the +65v adj screw and it was working. Once CR1732 replaced with a 1N4148 however, the adj screw no longer has any effect and the voltage remains at +61.8v.
With CR1751 and the +15v rail re-connected, the voltage on the 65v TP drops to about +39 volts. I don't have time now, but shall carefully go through all the components on the +15v section looking for something pulling the voltages down. Perhaps it will be another switching diode?
@ Roger
> I hope you are now on the home run.
Thank you. So do I.
Still can't quite see the wood, but the bark and leaves have now come into view!
James
James55