Samsung LCD TV LA40C650L1F Power Board

[tw2005]

Got this LCD, friend gave it to me. Found PSU BN44-00340A had issues.
dead, no stdby. backlights failing prior to total loss.

MI801S,MI802S 12N50 FETs blown,
FM801S 3.15A fuse

Now have stdby and erratic backlights, missed the small stuff and now it went pop.

I have no schematic and found no images good enough to work out the resistors which have burnt.

R1845,1859 30K
R1841,1846 270 ohm

need ID of R1844,1842

Bn44-00340B is a different board and cct

Images are SJ and not clear enough to get the numbers

Looking mid board underside



Fitted to

Le40c530f1wxxu
ln40c650l1fxza
ln40c670m1fxza
le40c550j1wxzg
le40c550j1wxxh
le40c550j1wxxc
le40c550j1wxxu
le40c550j1wxzt
le40c550j1wxxn
ln40c630k1fxza
ln40c610n1fxza
le40c650l1kxxu
le40c650l1kxxu
le40c650l1kxxu
ln40c500f3fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1fxza
ln40c530f1hxza
ln40c539f1hxza
ln40c540f2fxza
ln40c550j1fxza
n40c560j2fxza
le40c750r2kxxu

[tom66]

Re: Samsung LCD TV LA40C650L1F Power Board

Can you upload the images direct to Badcaps or to a site like Imgur? Shopjimmy is blocking UK IP addresses for some reason.

[vinceroger69]

Re: Samsung LCD TV LA40C650L1F Power Board

Ive just tried a few sites too too see if i can find the values ohms and chs do the kits with the resistors but no values listed and shop jimmy i tried looking at the pictures and still have this issue tom
https://www.badcaps.net/forum/search...archid=5963706

[tw2005]

Re: Samsung LCD TV LA40C650L1F Power Board

Can you upload the images direct to Badcaps or to a site like Imgur? Shopjimmy is blocking UK IP addresses for some reason.

Ive just tried a few sites too too see if i can find the values ohms and chs do the kits with the resistors but no values listed and shop jimmy i tried looking at the pictures and still have this issue tom
https://www.badcaps.net/forum/search...archid=5963706

Sorry, forgot about that. I've looked pretty hard, as I do. I've tried google images, Ebay ads, other site that sell boards SJ etc. Tried searching the numbers and models here, get hit but again the couple of images are no good and no one has mentioned any info for these resistors, I guess at the time easier to get a whole board.

As irony would have it, the "B" revisioson you can get the schematic and on the SJ site you can see the values in the photo.

The "A" version, no schematic and SJ image not good enough........conspiracy theory??

Little annoyed I did not have a close look earlier, may have been able to read at least one side since it has 2 FEs with the same cct for each.

The B version schematic may give some clues but it setup different. Just the value needed for these the rest I've worked out

[tw2005]

Re: Samsung LCD TV LA40C650L1F Power Board

Thanks to Sevenqi who sent these images to me.

Unfortunately, I replaced the parts and the TV lit up but I noticed flickering. After a while you know when you get that resin odour from the PCB things are heating up and sure enough the heatsink with FETS MI801S & MI802S was red hot. After a few cycles when I started adjusting the backlight that familiar pop was heard.

To help others here's a list and most of this was damaged on mine which had no stdby. I did not replace UM801S IC so maybe that was the issue.


FM801S T3.15AH, 250V FUSE
UM801S STRW6052S
MI801S FDPF12N50UT
MI802S FDPF12N50UT
RM811 0.3 OHM 1W
RI842 30 OHM
RI844 30 OHM
RI843 100k OHM (Marking is 01D)
RI848 100k OHM (Marking is 01D)
RI845 30K ohm
RI850 30k ohm
RI841 270 ohm
RI846 270 ohm
QI801 2N7002K (WC)
QI802 2N7002K (WC)
DI809 BAV70
DI811 BAV70