SEM3330, S3330 SMPS IC from Samsung BN44-00697A

[midnightg35x]

Hello,

I am trying to repair a samsung power supply BN44-00697A out of a samsung UN32H5500. It originally blew the main fuse because of a shorted transistor. I replaced all the damaged components along the way except one. It is ICM801, with the markings of S3330. When I try to find the component online, the only place I see it available is from aliexpress. I'd rather find either an alternate source or an alternate part not from aliexpress. I have not even been able to find any sort of datasheet or other schematic that uses this same chip so I'm having issues trying to troubleshoot it. I get rectified DC voltage of 170V up to the main 450V caps.

This power supply only uses a constant 13V (A13V on CNM803) that goes over to the main board. It is reading 0V and it looks like that 13V is generated directly off of transformer TM801S which also appears tied to the ICM801 output. The fact I don't get anything out of ICM801 makes sense as to why I'm not getting the 13V. If anyone has a datasheet of the SEM3330, S3330 or a reputable source for them, any help would be appreciated.

Pictures below from shopjimmy

[diif]

Re: SEM3330, S3330 SMPS IC from Samsung BN44-00697A

Sometimes the only place is Aliexpress or ebay if time is important.
https://www.aliexpress.com/item/S333...672558244.html
Confirmation in the feedback they have been fitted and tested.

[dick_barton]

Re: SEM3330, S3330 SMPS IC from Samsung BN44-00697A

I found this that could help

With the NCP1203D6 you can also replace the following (quite expensive and harder to find): 34A65-PANASONIC, PF6200-PHILIPS and S3331-SAMSUNG.
http://www.elforum.info/topic/117426...t-bn44-00697a/

[midnightg35x]

Re: SEM3330, S3330 SMPS IC from Samsung BN44-00697A

I found this that could help

The NCP1203 and FAN6755 look similar, but not pin compatible with each other. Pin 1 on both seem to have different functions. I feel the FAN6755 is a better fit, but if anyone has a better feel for this please let me know.

Is it a better idea to take a chance on aliexpress or the more procurable FAN6755?

[midnightg35x]

Re: SEM3330, S3330 SMPS IC from Samsung BN44-00697A

I went ahead and am trying the aliexpress route. I'll report back if/when I get them and install them.

[midnightg35x]

Re: SEM3330, S3330 SMPS IC from Samsung BN44-00697A

Well that experiment I think we can call failed (or something else was wrong). Got the chips the other day and installed one. Being in haste probably caused me more damage though. I happen to leave the cable to the LED's and the cable to main board plugged in when I tried it. I should not have done that. When I applied power, one of the 250V 15uF caps on the LED driver almost instantly vented. At the same time, one of the 3 amp regulators on the main board actually blew a pin out of the package. The LED backlight was going crazy also. I do not know at this time the extent of the damage to the other boards besides the power supply because I do not have a working one.

I might have to send this one to my scrap pile unless I can find time to try the power supply completely alone. Best case is the one regulator on the main board blew to overvoltage/overcurrent and protected everything downstream and the LED driver didn't actually take out any LED's along the way. Worst case is everything is fried Live and learn.

It means the aliexpress route didn't work for me this time at least. I can't be sure it was the chip I got or if something else was bad. This power supply is actually fairly simple compared to most.

[midnightg35x]

Re: SEM3330, S3330 SMPS IC from Samsung BN44-00697A

I eventually figured enough was enough on this one and just found a complete replacement board for $25. The TV still does not work, but I think I will open a new thread as the title of this thread is no longer valid.