I recently posted a topic about my newly-rebuilt ST070 (with a VTA PCB) giving horrible problems at first startup:
Well, acting on the excellent advice of a couple of members here (Thanks again)! I double checked my wiring and found no problems. I then looked through the Curcio trouble shooting guide and did the following:
- Replaced the rectfier with a solid-state one from eBay
powered up with NO tubes or rectifier: powers up fine.
Powered up WITH solid-state rectifier: power up fine.
I then measured the voltages at pin 5 of the power tube sockets (no power tubes) and got this:
Rear right -43vdc
Front right -42.2vdc
Rear left -43vdc
Front left -43vdc
This seems within spec, right? Doesn't this rule out the quad cap and power trans?
So what now? I don't have any way of testing the power tubes and the Curcio guide suggests power tubes could be at fault. SO.....what would my next step be? All the Dynaco manual test points seem to be WITH tubes: and since I can't trust the power tubes, what to do next??