LJ41-04216A Cap C4712 trace damaged

[Easky15]

Hi all, I was repairing a 50 inch samsung plasma with a power fault, got the power board repaired and tested and the tv now works ok but before a reassembled i seen a bulged cap on the x main board but when i was removing this i accidentally damaged the trace, I tried to scratch away a bit of the green covering to get to a trace to resolder the positive pin of the cap to but i cant seem to find any copper so can someone please tell me where i can solder a trace to as my circut tracing skills aren't the best, i'm still learning the ropes.. ;-)

Also could someone tell me where is a good place to find schematics,..

[tw2005]

Re: LJ41-04216A Cap C4712 trace damaged

These boards are double sided. On that lead there is no connection on the bottom side but there would have been a pad purely to add strength and reduce strain on the top pad which is where this is connected to.

I think I have one of these laying around but if you go to SJ you can see the underside and there is white masking there but no copper trace, just a pad.

I did the same thing on the Ymain for the same series on a 680uF cap. Lost the bottom pad desoldering it. Just neaten that leg so it can't touch the exposed copper you have now created.

To my knowledge you won't find any schematics for these. You will with the panasonic TVs.

[tw2005]

Re: LJ41-04216A Cap C4712 trace damaged

Well did not take me long to find the board. Pretty obvious there is no connection there. If you attempt to solder that lead to the nearest copper land then you will be shorting the - and + sides of the cap and what do you know, this is a 680uF cap.

what a coincidence.

[Easky15]

Re: LJ41-04216A Cap C4712 trace damaged

Right i have got the set working but a prety loud buzzing sound coming from where that 680uf cap is located.. :-o

[Easky15]

Re: LJ41-04216A Cap C4712 trace damaged

Ok so I've tried a few times now and still cant get the tv to work without buzzing, Is there any other locations i can solder this 680uf cap to to get the set working again, Here's a few pics that might help, Be warned, It's not pretty.. ;-)

[tom66]

Re: LJ41-04216A Cap C4712 trace damaged

Scrape off the soldermask around that adjacent trace and solder to it. Same for ground.

Do be aware that these plasmas are prone to buzzing if:
- case is not fully secured
- board is not fully secured
- inductor resin (on the coils in the middle of the board) has dried out

[budm]

Re: LJ41-04216A Cap C4712 trace damaged

I would lay the cap on its side so you can easily solder the top side of the board which is connected to the B+, the bottom side you can scratch off the greens solder mast of that big trace which is connected to the fuse and bend the cap's leg over and solder to the exposed copper.

[Easky15]

Re: LJ41-04216A Cap C4712 trace damaged

No joy.... Back to clicking now, Does this look right what ive done??

[Easky15]

Re: LJ41-04216A Cap C4712 trace damaged

Just noticed your post there now tom, Screwed the board down and thats the set now fully working with no buzzing, Thanks very much everyone for all your help.. ;-)