Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
The TV would power on and you could hear a chime, and the standby light blinked but there were no backlights, no picture, no image on the screen with a flash light on it.
The obvious parts that were faulty were the little power transister and the blown fuse. The power switch was visibly blown and destroyed and the fuse tested open in circuit.
Location UM801S - Power Switch Part# STRW6252
Location FS801 - Fuse T3.15AH 250V
I bought the kit from here:
[url]www.ebay.com/itm/Samsung-BN44-00261A-11pc-parts-kit-LN32B550K1F-LN32B530P7F-LE32B530P7WXXU-S2/142490605351[/url]...
lucidbarrier
Senior Member
Last Activity: 09-01-2019, 04:37 AM
Joined: 07-07-2012
Location: SA/TX
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
So today I put some compound on the power IC, soldered it in and swapped out the fuse that was open. I decided not to replace the little FAN7530 IC and to check the voltage at the main filtering cap to see where we were.
I plugged in the power cord and the backlights immediately came on and I saw about 386v at the filtering cap. So I reattached the T-Conn and main board and threw on the rear cover to test it.
And it came on with a beautiful picture! I knew this TV had a lot of potential because...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
Thanks, I bought some GC heatsink compound today at Altex. It says perfect for power ICs so that's the main reason I got it....Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
Wow that WES51 temp controlled soldering iron really makes a difference! I wish I had bought this thing years ago.
I noticed that the power IC has heatsink compound on it. What kind of heat sink compound do I need to use? All I have is Artic Silver 5 but that contains silver and this looks like the old school white stuff....Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
While I was looking for that QB801, I noticed that there have been a bunch of components replaced on this board. There are diodes and capacitors and little resistors and FETs replaced. Some of the soldering is kind of iffy. The larger things look good but some of the tiny SMD components look a bit crooked. He didn't trim the legs far enough on the STRW6252. I went ahead and sent for a return on this board. It's one thing trying to find a failed component on a virgin board but then it's another trying to fix something...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
I'm not too sure which diodes are the ones I need to check but those big diodes DP804 and DP810 are not shorted, they test 0F in one direction and .488v in the other direction (in circuit).
I was looking at another thread with a similar board and I am assuming the PFC IC is the FAN7530 at UP801S?
Reference:
[url]https://www.badcaps.net/forum/showthread.php?t=55254[/url]
So with the black lead hooked up to the neg - lead of the main filtering cap and the postitive...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
Yes sir, thanks for the help!...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
Looks like 166v across the 2 leads, main board unplugged and power cord plugged in...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
Well, I unplugged the resistor and plugged the power cord back in. Either way, no backlights and it's completely black. Not even a flicker for one second.
Pin 1 = .8v
Pin 3 = 5v
Pin 23 = 5v
So either it's the inverter or the backlight bulbs are burnt out?...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
Ok maybe I wasn't understanding this before but i think I got it now. I disconnected the cable right at the main board and stuck the resistor in there.
When I jump a 1k Ohm resistor across Pin 1 (PS ON) and Pin 3 (standby 5.3v)
and plug the power cable into the power supply, I get these readings:
Pin 1 = 1.5v
Pin 3 = 5v
Pin 23 = 5v (INV ON/OFF)
The screen is completely black. So the Inverter should be on at this point since there is 5v...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
I was taking the boards off to take pictures and I flipped the main board over and there's a whole mess of corrosion on the back....Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
I'm not sure I was doing that right. I put a 1k ohm between STANDBY and PS ON and a 1K between a 5.3v rail and INV on, but there's no power going to the infrared module/power button if the main logic board is disconnected.
So I plugged it back in. Pulled the cover off the T-CONN and checked the continuity of the fuse. It was good. There seems to be voltages present on the pads next to the LVDS cable exiting the main board to the T-CONN. So I pulled one of the ribbon cables from the T-CONN going...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
So if I put a jumper across the 5.3V rail across to INV ON and PS ON, will the backlights come on?Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
I guess I forgot that one
Pin 1 = 1.163v (tv on) and 0v (tv Off)...Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
It acts like a dead set. No standby light, no chimes, just a black screen. I measured the standby voltage to see if I might have popped a fuse, but the standby voltage is still there. I plugged the connector to the main board back in and the standby light comes back on....Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
So I ordered a replacement power board on Ebay and it took ages to get here. It is the same part number but a different revision. The cable going from the power board to the main board on my TV is has two rows of wires in going to the connectors. The replacement board only has a single row. I reused the existing connectors from my TV. I checked both boards and they have the same pin out at the connector.
I installed the board, and the red standby light is lit up. When I press power on the remote, the standby led...Last edited by lucidbarrier; 09-13-2017, 01:48 AM.Leave a comment:
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Re: Samsun LN32B550K1F with BN44-00261A burnt out IC
It's the CM808 that I couldn't find. It's a Sam Young too. It looks like the 2 Zener Diodes are there too. Can I test the ZDs in circuit? I think diodes are continuous in one direction but not in the other?
Edit: The other caps "look" ok, but if I do get the parts for this thing, those NXB caps are going too.
Thanks for the help!...Last edited by lucidbarrier; 08-28-2017, 04:59 PM.Leave a comment:
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Samsun LN32B550K1F with BN44-00261A burnt out IC
Hi everyone
I just recently acquired a nice little Samsung LN32B550K1F 32" LCD TV that wouldn't power on.
Looking at the power supply/inverter board BN44-00261A , it appears that the component at location UM801S is completely destroyed.
It seems that similar inverter/power boards have that same IC pop on it. Shop Jimmy has a video about installing a kit for a BN44-00264B. I was able to locate a schematic and it appears that component is a STR-W6252 , althought I have no idea what it does. I thought it was a MOSFET but it has too many legs.
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Re: HDMI port replacement on Radeon 4650 advice
I tried to use a solder sucker and the holes are just too small to get it to work just right. I do have a desoldering iron somewhere but I was starting to get worried about messing up the vias. I used the pick but I kept melting the solder from the other adjacent holes.
I had wiped off that fast chip on the sponge and just sopped it up with the iron today and made a little puddle over the pin holes. I pushed the hdmi port right through with like no resistance. This stuff really is amazing. It was kind...Leave a comment:
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HDMI port replacement on Radeon 4650 advice
I tried like heck to get the solder out of those tiny pins on the HDMI port. I used flux, a wick etc. I finally learned about Fast Chip (or ChipQuick) and bought some. I slathered some on and then pressed gently on the pins with the flat side of the chisel tip and they went through cleanly. It was amazing how nicely it worked.
I cleared the two large holes that secure it to the PCB using the dental pick method that I learned from you all. The little tiny holes are a different story.
How would you all recommend clearing those holes? There are 19 tiny holes. Should...
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