techwood 32". replaced psu and now standby light is flashing intermitantley

[conman78]

hi, im a newbie at this so please be gentle. i've got a techwood 32" lcd that wasnt working.

when i opened it up i noticed the fuse on the power board was blown.the power board is a 17pw15-8  i went to maplins and bought the same rating fuse . they were the quick blow type . put one in and turned it on and it literally blew the fuse into pieces ? does anyone know what part on the power board could be causing this please ?

[mulja]

You need buy a KIT

[conman78]

hi mulja . where can i get a kit please and do you know what they consist of ?

[mulja]

Try here:

http://www.ohmsupplies.co.uk/epages/ohmsupplies_co_uk.sf/en_GB/?ObjectPath=/Shops/ohmsupplies.co.uk/Products/KIT10

[conman78]

thanks, i've orderd a complete board from flee bay to get the tele going for now.  i'd like to have a go at repairing the board anyway so i'm going to order a repair kit aswell . thanks for your help. much appreciated

[PMZ]

   Hi conman78
  Don't use quick blow fuses in any case as they cannot withstand the inrush surge. Use anti-surge types as denoted by A/S***mA or A as the case may be.
  Regards,
   Paul. (who learnt the hard way)

[conman78]

hi paul. thanks for that mate , i wasn't sure which one's they used so i thought i'd go with quick blow to be on the safe side. i've bought a board from flea bay and put it in, i'm not sure if i've been ripped off tho .the fuse doesn't blow anymore but the power light that surrounds the power button on the television is just flashing on and off blue intermitantley and randomley,is this a power supply fault or could it be a fault with the main board ? there is no life when i press the button but when i switch the power off at the wall then the button light stays on constantley for a few seconds and then dies out ? . can anyone help me on this please ?

[watteau]

Hello
There are slight differences with these PCB's.
If they have the same panel number, and sockets,
check the values of resistor R965 (near sockets),
and on the print side, R966.
R965 could be 3K3, or 680R, and R966 1K, or 150R.
Hope this might help.
John

[conman78]

hi watteau . thanks for the help m8 its much appreciated. i've checked the said resistor's etc and they are all exactly the same ? i'm pickled now because i've got one psu that blows the fuse apart and one psu that makes the stand bye light flash randomly ? has anyone had a similar fault where the blue standbye light that surrounds the power button flashes ?

[conman78]

hi , i've changed the 15uf caps c877 and c878 , still pulsing ? so i pulled the plug pl803 of the board and instead of the standbye light pulsing - the back light of the screen pulses ? if i put pl803 back in and pull out - g800 then i get pulsing standbye light again ?  :wallbash:

[brainstorm]

Hi, it seems like you are having fun! I would make certain that you have bought a identical board to the original first, this is a vestel power supply and there are a lot of variations, so scrutinise all the components,etc, If you are sure you have the right board then you probably have bought a faulty board(unless you are unlucky and have another fault). I dont know if you are an engineer or not,but my experience on these boards is that the majority of faults is usually a electrolytic capacitor faulty, if you have a ESR meter check each one in turn, if you dont have a meter, then look for a capacitor with a "bulging" top - failing that then your best option is to buy a repair kit for your original board.

[conman78]

hi brainstorm, thanks for the advice m8, i checked the boards when i got them and they were identical , no bulging caps though   :bo:
thinking about investing in an esr meter though.

i'm not an engineer . i'm just a novice hobbiest trying to fix my own set .

i've sent it to a guy to be tested now but i will post the results of repair up just incase anyone else has the same prob !

[conman78]

ok guy's , i sent my two faulty power boards off to a guy i met off ebay . he sells these boards  and other television parts . his ebay id is -  sparedparts , so check his ebay site for spares, he sells these boards for a very reasonable £45 + postage and is both a top bloke and 100% genuine .

unlike ebay member -  juraseknr who sold me a faulty board  :sad:

 sparedparts managed to repair both my boards for me 

and sent me the following results -

Board 1. which was blowing the 2.5amp fuse had a faulty bridge rectifier,

Board 2. was pulsing in standbye  - which was the power factor and regulator ic faulty .

hope this helps someone 1 day who has the same problem . many thanks to all those who offerd advice and help on this.