Re: Samsung LN46D-550SK1FX- No Power, No LED- Blows AC Fuse

Couple questions- which resistors are these? The set near the main board lead (RM817) or the set to the right of bridge(CX8015)? Or am I completely wrong in my guess? Also how do you check VCC at PFC? It is pin 8 from the data sheet and I have the voltage range on the sheet. Do i just check to see that it is 13-20 v when plugged in?

Re: Samsung LN46D-550SK1FX- No Power, No LED- Blows AC Fuse

Ok jumpered both ways and get no change in caps. Both still at 174. Could I have screwed up the soldering of the controller IC and get this or is it something unrelated?

Re: Samsung LN46D-550SK1FX- No Power, No LED- Blows AC Fuse

Ok dcv is starting at pin 1 and going across top: 13.17,13.17,13.17,13.17,0,5.2,5.2 next going across bottom from 2 : 5.02,0.00,0.01,0.00,5.20,3.08. On the large caps each measures 174 and on cni801 from pin 12: 12.28,13.15,12.44,0.00,0.00. So not getting 360 on either cap.

Re: Samsung LN46D-550SK1FX- No Power, No LED- Blows AC Fuse

Ok we are making progress. I replaced both mosfets and the bridge rectifier and ic controller( tough to solder that tiny chip). It stopped blowing the fuse right away and i get the red standby light and it blinks when i hit power but nothing comes on screen or sound wise. What do i check next? When plugged in i think i am getting proper voltage on main board side so dont think it is that. Not sure where to go from here...Any help would be appreciated.

Re: Samsung LN46D-550SK1FX- No Power, No LED- Blows AC Fuse

Ok finally had some time to pull out what I thought might be bad and it looks like one of the mosfets is bad. I have uploaded a couple more pictures pointing out the culprit. Upon closer inspection the solder had appeared bubbled. I tested the bridge rectifier and it appears to be fine. Not sure exactly what is meant by "check the pads" but I did look for shorts across where the removed parts were connected and do not see anything. Anything else outside of replacing this mosfet I should test? Trying to minimize...

I have a Samsung LN46D-550SK1FX LCD TV that recently died randomly while watching it. There is no POWER and no LED light. I pulled it off the wall to find the AC fuse was blown. I replaced the fuse and it immediately blew again. I unplugged the two other boards and it still blows the AC fuse immediately upon being plugged in. There is no visual damage to the board (burn marks etc.) and no bulging caps. I am a bit novice when it comes to testing components but with a little reading I checked the caps and each is able to load and discharge via multimeter. I checked the diodes and they are all working....

Re: New Members - please post your introductions here

I am Brett. I came across this forum when trying find a way to resurrect my Samsung LCD. I enjoy learning and a challenge. Hoping to get some help fixing my power supply board.