I got the new SSB board, plugged it all in. and it bingo - it worked. By worked i mean, came on and displayed "inital config & language choice" screen.
I power cycled it several times and it appeared to be good.
I put it to one side for a couple of days as i needed the precious bench space. plugged it in again. and it's back to the same fault???
So either it's popped the new SSB (while the power was off - unlikely) or it wasn't that all along
/sits back stares at ceiling & scratches chin/
for clarity.
Apply power. Led goes RED. all outputs on PSU fire up (24V,12V (11.89 measured) and 3.3V).
If you press the power button on side of set, PSU goes into standby mode and Led goes off.
Press again, PSU fires up, led goes red and again nothing else happens.
I checked c505 & c130, both are near enough within tolerance. ie within 2% of stated capacity and ESR of around 0.3 and 0.7 ohms (i forget which was which).
The primary reservoir cap is 450V 120uF and that measured at 111uF and ESR 0.77 which is a little on the low side but its not bad enough to make the supply whistle (yet).
I pulled c537 & c100 as suggested earlier and they both measured good.
I think the Vp rail cap might be in need of replacement.... I'll finish up this post & go swap it out and see, it's a 470uF/35v measuring at 414uF, esr quite high too 0.1 - but it only supplies for the audio amp (i think)??
I have two service manuals for this set (LC4.31E AA 3122 785 16210 and supplement AB), and irritatingly neither have the circuit diagram of the 32" psu - anyone out their got it i would be very grateful, though i don't think the fault lies with the psu board.........
