17-08-2017, 04:51 PM
Having scored a success with my 33 and FM3 http://golbornevintageradio.co.uk/forum/...p?tid=6462&pid=70501#pid70501 I thought I'd take a quick lookat the 2000. It's been rather neglected for a few weeks. I've changed most of the electrolytics and the dubious looking 1000V mixed dielectric caps on the convergence board.
So I plugged in all the boards except line timebase and EHT, placed fingers in ears and switched on. Was rewarded by a fairly bright flash from somewhere I couldn't identify but might have been around the scan coils plus a fairly quiet pffft noise. No magic smoke that I could see.
Pulled out all except PSU, regulator and IF. Got another flash and pfft. Bit odd. There's nothing that's running at high voltage or power in the IF and I'm pretty sure the flash wasn't from IF, PSU or regulator.
Went back to PSU and regulator only which I've had powered up before. All calm but not much at the regulator pass transistor (VT2, VT3) collectors. Time for some proper faultfinding. Start with getting the main 55V regulated supply to work. With luck the pair of 30V supplies will also come up at the same time.
So I plugged in all the boards except line timebase and EHT, placed fingers in ears and switched on. Was rewarded by a fairly bright flash from somewhere I couldn't identify but might have been around the scan coils plus a fairly quiet pffft noise. No magic smoke that I could see.
Pulled out all except PSU, regulator and IF. Got another flash and pfft. Bit odd. There's nothing that's running at high voltage or power in the IF and I'm pretty sure the flash wasn't from IF, PSU or regulator.
Went back to PSU and regulator only which I've had powered up before. All calm but not much at the regulator pass transistor (VT2, VT3) collectors. Time for some proper faultfinding. Start with getting the main 55V regulated supply to work. With luck the pair of 30V supplies will also come up at the same time.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
