Wharfedale LCD3210HDAF

[norman]

Hi folks, I have one of these for repair, it is stuck in standby,blue light on. It has a vestel chassis with the 17PW15-9 power supply. I think the power supply may be faulty, does anyone know how to check power supply,or overide the standby. Please help with any suggestions. Thanks Norman.

[norman]

C'mon guys don't be shy, any suggestions welcome, even if it is bin it. I can't help but notice so many posts but few replies on here. Please help, I won't take offence at simple solutions. I may have missed something basic. Norman

[tv tony]

hello norman, we spoke before about repairing lg y-sus pcb.s (px11)
yes u are missing something simple, so am i!!!!
ill dig out my notes on this supply
hopefully today
regards tony walker

[tv tony]

Its come to me now, stuck in standby can be caused by c877 and c878 both box type caps 15n 400v. But the fault which is causing most of this is Q837 suface mounted transistor type bsh103 which is connected to pin 8 of sg3525a control ic807. This transistor is in the soft start of IC807, let me know how you go on
tony walker

[norman]

Hi Tony, Many thanks for the suggestions. I will have a go over the weekend end and report back. Thanks Norman.

[Ohm Supplies]

Norman,


I've just added all the cct. refs to the kits we sell on our webby, its not a bad idea to check them if you have a power supply problem as although the kits are to fix a dead supply they do sort quite a few problems with the board cutting off, after your swapped the 2 caps tony has said.

To pull the supply out of stand by you only need a couple of volts so you need a seperate power supply, I'll get the notes we use in work but you need to check if the votages are there in full, lower than they should be or varying.

untill they're steady then you dont need to be worrying about adding any extra voltages as its likley to blow something (else)

regards
Andy

[norman]

Hi guys, Thanks for the replies. The caps C877/878 are fine. The fet Q837 checks ok? I have two of these boards and the readings are the same on them. I can't try these in the set as they are an earlier version which doesn't fit (different connectors). The standby supplies seem ok. The circuit I have is very poor quality and not easily read. Does anyone have any training course notes for these? Hitachi used to be good for notes but I don't get to any courses assuming they still run them. I will have a look at your site (ohm supplies) for further information. Any further suggestions most welcome. Cheers Norman.

[norman]

I had another go at this today and found one of the double diode packages short circuit. (new I had missed something simple). I would still be interested to see you notes on this supply Tony if you can oblige. Many thanks for your input guys. Norman