Bush LCD32TV07HD no picture

[madmatt]

Hi All,
Well after fixing my own tv(Thanks a lot to the info from here!) I went and told some mates, who have promptly thrown another one my way.
Model is a Bush LCD32TV07HD and on startup there is sound but no picture(Or any backlight at all that I can see.
I popped the back off and expected(Hoped) to find some bulging caps as on my last one, but there is no obvious damage.
I'm suspecting an inverter problem(HPC-1655E), but also wondered if this cap(see photo) should look this way(Is it a capacitor?)that is on the PSU(FSP204-2F04)-Seems a bit bulgy?
As you can tell I'm a newbie, but get a great buzz from fixing things!
Thanks in advance
Matt

[tom66]

Re: Bush LCD32TV07HD no picture

I think that cap is OK.

Check if you have 24V going to the inverter(s) on the display panel.

It looks like an FSP PSU board and the caps look like Lelon. They could still be failed.

[JonathanAnon]

Re: Bush LCD32TV07HD no picture

Have an LCD screen here myself with the same issue... If the problem is singularly inverter/backlight related, you should be able to shine a torch on the screen and view the picture.. This will confirm that the main board and power to other boards is working properly.. then you can focus on the inverter board and the power source to this board..

[tom66]

Re: Bush LCD32TV07HD no picture

^That trick is great, but it doesn't work on all panels, especially Chi-Mei and Chungwha panels, which the cheaper TVs tend to use.

[madmatt]

Re: Bush LCD32TV07HD no picture

Thanks guys, will try it tomorrow and report further
Matt

[madmatt]

Re: Bush LCD32TV07HD no picture

Hi guys, sorry for late reply but not had time to look at tv till now .
Shining the torch worked! I can see the picture when holding a light to the screen, so will look at inverter board now. Will keep checking this forum throughout the day for more suggestions!
Cheers guys
Matt

[madmatt]

Re: Bush LCD32TV07HD no picture

Here is a photo of the master, then slave inverter, and also a close up on the pins of the transistor.Is this scorching normal?
I can't see anything obviously wrong, and although I have a multimeter, I havent prodded it anywhere yet(Wouldnt know where too, but eager to learn)
Matt

[madmatt]

Re: Bush LCD32TV07HD no picture

Also just noticed when i turn the tv on it will only turn off using the remote! The on/off button on the tv has no effect other than to turn it on. Does this help?

[madmatt]

Re: Bush LCD32TV07HD no picture

Any help guys? The are HIU-813-m and -s inverters.

[tom66]

Re: Bush LCD32TV07HD no picture

Have you tested the FETs for shorts? Just test between the three combination of pins. You're expecting infinite or near (hah) for most of them.

[kevinm34232]

Re: Bush LCD32TV07HD no picture

Matt I literally just got done replacing same inverter boards in a Toshiba 32AV500U. Here is another thread on it:

https://www.badcaps.net/forum/showth...light=32AV500U

The quick story:

-I had no backlight when I first got the TV.
-Shined a light in saw the pic..
-2 Mosfets were shorted on slave board aswell as fuse.
-Seems to be a common issue that mosfets and inverter IC fail. They sell them on ebay as a kit, 4 mosfets and the IC. Ordered and replaced parts.
-Intitially it didn't fix it, I reflowed the solder on the IC and had to leave, when I came back TV lit up and worked for about 2 hours then backlight went out again. Fuse was still good and mosfets did not show shorted.
Ordered 2 new inverter boards for $28, just got them today and installed about 20 mins ago, so far so good.

Assume some other nearby component was damaged on the slave board and shutdown circuit seems to be very sensitive. I just chose to replace the boards which in hind sight would have been more practical but I wanted to give it a shot..

[budm]

Re: Bush LCD32TV07HD no picture

Can we get good closed up pictures of the multi pin white connector of both Master and Slave inverter boards?

[madmatt]

Re: Bush LCD32TV07HD no picture

Ok, here are the photos as requested.Master is the one with 2 red wires.
Thanks for the advice, seems I may need to buy the inverters? The inverter repair kit looks tricky, and risks doing more harm than good in the hands of someone like me with limited experience.

Regards

Matt

[madmatt]

Re: Bush LCD32TV07HD no picture

What are your ideas guys? Should I get a pair of inverters or could it be something further up the line, and I just end up zapping 2 good inverters?

[kevinm34232]

Re: Bush LCD32TV07HD no picture

So have you checked the FET's for shorts yet?? If you're not comfortable with the soldering of the components you should probably order a replacement..

[madmatt]

Re: Bush LCD32TV07HD no picture

All I've done in the past is capacitors, is there a recommended YouTube video on testing fets and replacing them? Wife is starting to moan about bits of tv on the dining room table! Need to get this sorted ASAP. With just the backlight u/s I assume the problem is with the inverters and the power to them is ok?
Just worried about damaging 2 new inverters should I get them
Regards
Matt

[tom66]

Re: Bush LCD32TV07HD no picture

Did you check the 24V supply to the inverters?

If that's good, everything else should be fine.

[kevinm34232]

Re: Bush LCD32TV07HD no picture

Matt with the back off the slave inverter is on the right side. Set your meter to ohms and check between these pins (I believe it is left and center pin) and see what you have. If it's shorted it will be close to 0 ohms.. Check the Master if not. The IC is 32 pins you will probably want to repalce the whole board if one is shorted.. BTW this is a common failure on these inverter boards..

[madmatt]

Re: Bush LCD32TV07HD no picture

Hi Kevin,
Many thanks mate, you are spot on!
Do I just need to replace the slave board, or both?
What would the reason for the short be? Could the next board blow if I don't check something further up the line or is it just a case of bad/worn components on the inverter?
Many thanks kev(and everyone else's input)
I shall start a search for a board, but await reply re buying the pair

Matt

[madmatt]

Re: Bush LCD32TV07HD no picture

Would this be a good buy?

eBay item number:

170915768528

Regards

Matt