Bush IDLCD37TV07HD Power Supply

[welshblob]

Hi,
I've been lurking for a couple of weeks as a guest and having fixed a couple of Bush LCD's I was onto my third, a IDLCD37TV07HD. Was told that it was dead and a tv repair man had looked at it and said it needed a new PSU. The PSU is a FSP312-2M01 rev 1 / 3BS0158413GP and once out of the TV I could see that someone had replaced the onboard fuse with a dodgy fuse holder and 2A fuse (rather than the 5A listed on the board). There were also 3 caps bulging which I then replaced;
CS17, CS10 = 1000Uf 25v
CS25 = 680uF 35v
The only other damage I could see was that some surface mount resistors (R52,53 and 54) on the underside of the board looked like they had taken some heat .... but I didn't test\replace them (doh!). On powering up after replacing the caps the TV still didn't have any power and after a couple of seconds a crackling noise and smoke ..... from R52,53 and 54 which are now quite burnt (see pics). So some questions;
1) I've managed to get a used PSU off ebay but is there anything that is likely to cause it to fail such as the inverters?
2) Is there any hope of repairing the current PSU? I believe those resistors may have originally been shorted but not sure if anything else has failed on it.
Any help would be appreciated and photos attached.
Cheers
Rob

[Turnip]

Hi Rob,

Not met a FSP312 yet, but wonder why three resistors in series should burn up. Generally they're a voltage dropping device where applied voltage precludes just the one resistor.

Curious - Chris.

[welshblob]

Hi Chris,
I'm intrigued as well and makes me think something else has probably gone. As soon as I get the replacement PSU I'll get their values and get an order placed. I've never really done any surface mount soldering so it should be fun 
Cheers
Rob

[jacksonliam]

Hey Welshblob

Ive got the same TV here, just wont turn on, no lights, nothing.

It broke when someone shook it, tripped out the main electrics which makes me think something inside must've grounded!

Have had a look at the power supply, signal board and inverter board but I cannot see any damage.

Couldn't find the 'internal fuse' you speak of, where is this?

Any ideas of what to look at?

Thanks,
Liam.


PS - This TV seems identical (internally anyway) to the Onn AO37ZID

[welshblob]

Couldn't find the 'internal fuse' you speak of, where is this?

The fuse is right next to the 240v connector under the large aluminium plate. On the replacement PSU I got it appears to be a normal 20mm fuse, covered in black heat shrink with wires coming out which are then soldered to the board.

As for what the problem could be I don't know. I'd tend to agree with you that something has probably grounded so are there any loose cables or boards inside?

Rob

[welshblob]

Finally swapped out the PSU and it now works fine without any smoke and burning. However on the freeview tuner it keeps coming up with "This channel can not be shown, channel is scrambled" on the info panel at the bottom on the screen and it doesn't disappear. I don't have the remote so not sure if I can get rid of this. Anybody know why this might be coming up, do I need to do a proper service menu reset or update the firmware?
Here are the details from the system information menu;
Product ID : BX
Software Version : BEKO LX IDTV 1.5 (20071010)
Hardware Version : EMMA2LL 00006011 0001
MHEG Engine : 3.0.14

Rob

Edit : Problem solved, looks as though due to my lack of remote and playing with my harmony (pita when you don't have the original remote and logitech don't recognise tv!) I must have enabled some weird mode. Having now discovered the info button I've managed to clear it!