Samsung LA32C400 stuck in standby, red light on.

[Cap-tivated]

With reference to the thread...

Here

I'm wanting to repair multiple Samsung LA32C400 TVs. (Shares the same PSU as LE32C450)
Most have the same fault as described by the OP in the thread above.
I have not tested the actual psu boards but doning one from a fully working set does do the trick.
PSU board is again the BN440033A version (not B).

Soooooooo,
Q1) Is it safe to assume that the same brown poly cap as shown by martino is the one to attack on each of these faulty sets?

Q2) Another set comes on fine but once warmed for a minute or so has horizontal "interference" lines along the top third of the screen. What should I be looking at to fault find this?

Many thanks.

[Andrew F. Ali]

Re: Samsung LA32C400 stuck in standby, red light on.

A1) Can you do a self-test on the PSU using the car bulbs as dummy loads? If that works then I would still go ahead and replace the brown poly cap then go on to suspect the Main Bd.
A2) Lines on the screen most likely bad tab bonds or perhaps either the cut-off or the bypass method may be applicable.

Please post some clearly focused close up pictures of the screen problem and the PSU, so the experts can help you better.

[CapLeaker]

Re: Samsung LA32C400 stuck in standby, red light on.

Any pictures?

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Thanks for the replies.

I can answer just one point right this minute which is a photo of the psu. I'll follow up with more.

[budm]

Re: Samsung LA32C400 stuck in standby, red light on.

Can we see higher res pictures of that power supply board and also the whole back of the TV showing all the boards.
I cannot read the board P/N. BN44-??????
"BN440033A version (not B)" as posted is not valid number.

I cannot read the labels for each pin of the connectors or the Voltage charts as printed on the board either.

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Ah, looks like my phone and PB defaulted to low res, try again.





I'll do the rest later.

[budm]

Re: Samsung LA32C400 stuck in standby, red light on.

How about the pictures of the whole backside of the TV showing all the boards?
So the power supply board is BN44-00338A.

"Q2) Another set comes on fine but once warmed for a minute or so has horizontal "interference" lines along the top third of the screen. What should I be looking at to fault find this?" We still need the screen shot of what you are seeing.

[vinceroger69]

Re: Samsung LA32C400 stuck in standby, red light on.

psu schematic

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Here are the rest of the photos as requested.
Thanks to vr69 for the schematic.

Control board


Inverter board



Then finally the screen shot from my Q2

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Realised I hadn't conformed to picture requirements so here they are attached this time...

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

I didn't have any car bulbs to hand so haven't tried that test until I grab some.

"A2) Lines on the screen most likely bad tab bonds"

What's the method for checking the tab bonds?

"or perhaps either the cut-off or the bypass method may be applicable."


Could you explain or link to these methods please.

Thanks

[vinceroger69]

Re: Samsung LA32C400 stuck in standby, red light on.

As your tv has the lcd panel pcb and tab bonds at the bottom of the tv theres also a chance someone has used cleaner on the screen and possibly damaged the tab bonds im also not sure if a main board bga chip can cause this issue hopefully a more experienced member will confirm the video i linked shows bad tab bond issues but these i notice all have vertical lines your has horizontal lines i know budm has fixed his own samsung tvs with tab bond issues maybe he can advise you
https://www.youtube.com/watch?v=j7vl7-vZEL8

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Thanks again vc69!

I'll be giving that a go the first chance I get on the single TV with the lines and double image.

[attainteddragon]

Re: Samsung LA32C400 stuck in standby, red light on.

double imaging can be caused by tab bonds, so it could be panel.

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Ok, I gave the connecting ribbon my best shot for curing double image and lines but no matter what I did there was absolutely no difference, better or worse.

On this model set there is no separate TCON board that devides the screen into two halves with a ribbon for each. Therefore, I was trying this on the single ribbon leading directly to the board attached to the bottom edge of the screen.

For now I've swiped its PSU to use in one of the other sets that was stuck in standby.

I have confirmed the brown poly on the PSU boards as being a 1000v 22nf 5% (223J).

[vinceroger69]

Re: Samsung LA32C400 stuck in standby, red light on.

To get too the lcd panel tab bonds it will require stripping the tv rite down but theres alaways a risk of cracking the lcd panel or making the set even worse as its a combined mainboard and t con board i wonder if it this at fault i was hoping a more experienced member may chime in with there thoughts etc

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

That's exactly why I only went as far as loosening the frame a little at the base end so I could sneak a peek at was there. I couldn't see any more ribbons in there, just the same single ribbon connecting to what must be a combined board, very narrow, running most of the width of the screen.

Having failed miserably on a laptop screen repair (full dismantle for illumination problems) before I opted to stop there!

[Cap-tivated]

Re: Samsung LA32C400 stuck in standby, red light on.

Does anybody have further thoughts for a fix to the combo board as discussed above. Off to buy some poly caps tomorrow so hopefully other sets will be back on line, just leaving this one with lines and double image.

[Folxs]

Re: Samsung LA32C400 stuck in standby, red light on.

I'm searching for schematic of Samsung BN44-00330A - froma Plasma 42"TV

[vinceroger69]

Re: Samsung LA32C400 stuck in standby, red light on.

I'm searching for schematic of Samsung BN44-00330A - froma Plasma 42"TV

please ignore just realized yours is a BN44-00330A and not a bn44-00330b
http://electro-medical.blogspot.co.u...ply-board.html