Mulja tv repair portal

Equipment Repairs => LCD TV forum => Topic started by: kennyc on April 12, 2016,08:44:20

Title: TECHWOOD 32940HD DEAD
Post by: kennyc on April 12, 2016,08:44:20

Hi guys ,TV has a 17pw25-4 power supply with the 2 lines of 3 diodes . Has a 17MB62.2.6 AV board . Is dead and has no stand by light . If I disconnect the AV board the 5v stand by voltage comes up but when connected it seems to be tripping. Thought AV board was faulty but had old one that sound goes off after 3 hours . Put that in and still not working . So dont know if its the chicken or the egg . Have changed caps on power supply . Any way of checking if its power supply or AV board ,thanks if you can help

Title: Re: TECHWOOD 32940HD DEAD
Post by: Turnip on April 12, 2016,09:58:53

Hi Kenny,

May not be any use but checked voltages on a working one - Realise there are possibly five variations of 17PW24-4 boards - Chris.

Title: Re: TECHWOOD 32940HD DEAD
Post by: jordan on April 12, 2016,14:13:58

17pw25-4

Title: Re: TECHWOOD 32940HD DEAD
Post by: kennyc on April 18, 2016,06:01:35

Thanks jordan and Turnip for info . Will get round to checking TV on Monday . As usual customer told me it was taking to long to fix and he was buying another one to watch the football. So have inherited it . Am sure some people use us as a cheap place to get rid of TVs because the council charge £20 to collect them

Title: Re: TECHWOOD 32940HD DEAD
Post by: Davy on April 22, 2016,16:10:54

I had a funny un' turned out to be a zener on the T'con, have you tried powering with Tcon disconnected.... this was a Wharfdale LT26K1CB, a zener was leaky it's marking is 'CCD KE' a 5Volt type from what I gather, luckily I found one on a Samsung Tcon, but before fitting it I used a ..... standard wire ended 5.1V zener, this brought the set back to life.

In my case I changed and reprogrammed the Eprom - I now had a set I could switch off and on and it'd trip off just before the backlight came fully up, just about saw feint flicker gave the show away - something it'd never do before - the Tcon was the only board I never checked, why I made a bee line for that 5V zener I don't know.

Samsung can suffer from this problem, always worth checking it's Tcon or it's ribbon cable by disconnection just to see if there is any variation is the symptoms. Thought I'd just give it a mention.

Dave.

Title: Re: TECHWOOD 32940HD DEAD
Post by: kennyc on April 24, 2016,05:08:49

Hi Davy,no luck will have to wait till I get another one in and check the boards in that. Thanks anyway