PSU17IPS12 Component Identification and help

[cdragon]

Hi all,
My friend has asked me to look at his Bush DLED48287HDCNTDFVP TV, which has been sitting idle for 2 or 3 years after dying during an electrical storm.
The TV is totally dead with no standby light.
After removing the PSU which is a Vestel 17IPS12 I have found that the power diodes all appear to be working correctly and the main capacitors read about 320V DC.
However I have measured several different standby voltages from about 1.5v up to 3.6v at different times with no apparent consistency between them.
After putting the board under a microscope I have found that component U100 on the bottom of the board seems to be at least partly to blame.
The best I can make out is that it is a TL431 regulator in an sot-23 package but I'm not sure. I have attached photos and a schematic to this post.
Can anyone here confirm for me that it is a TL431? or if not maybe suggest to me what it actually might be?
Also, if it actually is a TL431, should I be looking elsewhere on the board for other damaged components as a result or is it possible that it alone is the culprit?
Any advice is greatly appreciated.
Thanks

[crazycavan]

Re: PSU17IPS12 Component Identification and help

hello
I confirm it is good TL431

[nomoresonys]

Re: PSU17IPS12 Component Identification and help

Looks like its cracked in half, if so it is a bad component.

[cdragon]

Re: PSU17IPS12 Component Identification and help

Thank you both for answering. I'm currently trying to source a replacement TL431. Is this likely to be the main source of the problem or should I also be looking elsewhere on the board?

[diif]

Re: PSU17IPS12 Component Identification and help

If you've checked in the vicinity for shorts, I'd just replace it. https://sparedparts.com/products/ves...ode-sot23-d200

[cdragon]

Re: PSU17IPS12 Component Identification and help

I have checked in the vicinity and everything seems to be okay. I'll go ahead and replace it and see how I get on. Thanks for the guidance!

[yokoono]

Re: PSU17IPS12 Component Identification and help

Check Fan 6300 (U101), Q105, etc, etc. That optocoupler didn't explode for nothing.

[cdragon]

Re: PSU17IPS12 Component Identification and help

Thanks yokoono, I will check those.

[cdragon]

Re: PSU17IPS12 Component Identification and help

I am ordering the TL431 from ie.farnell.com. i see quite a lot of versions to choose from. Could anyone guide me as to the correct one please? I can't find a datasheet for the TL431SAMF2 that diif has linked above. Particularly I notice that some of them have their pins mirrored. I don't want to get the wrong one.