31-10-2018, 08:35 PM
Hi.
The V410 developed a fault on switch on this afternoon. There was bad hooking on the top of the picture on both Aurora and Hedghog converters. One of the flywheel diodes had developed a leak, after replacing both with two 1N4148 diodes the hooking cleared but there was distortion on the verticals corresponding to the castellations. A quick look on the scope on the sync separator anode and video was leaking through. The sync coupling cap was new and the only resistor that was out of tolerance was the 150K anode load at around 260k, replacement was a cure.
There is no rhyme or reason to these resistors, some are well within tolerance and others wildly out, I think I'll need to more or less go through the lot before I do a final re-alignment.
The V410 developed a fault on switch on this afternoon. There was bad hooking on the top of the picture on both Aurora and Hedghog converters. One of the flywheel diodes had developed a leak, after replacing both with two 1N4148 diodes the hooking cleared but there was distortion on the verticals corresponding to the castellations. A quick look on the scope on the sync separator anode and video was leaking through. The sync coupling cap was new and the only resistor that was out of tolerance was the 150K anode load at around 260k, replacement was a cure.
There is no rhyme or reason to these resistors, some are well within tolerance and others wildly out, I think I'll need to more or less go through the lot before I do a final re-alignment.
