Help to identify IC51 and IC52 on PSU board

[Adenitz]

Hello,
I have a computer display PSU board TDK287A, EA12B287T.
On this board, in the 5V and 12V section there are transistor like (three legs) parts labeled as IC51 and IC52

The part labeled as IC51 has the following labels:
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431G or 4316
545PG or 545P6
I suspect that this IC51 could be TL431 regulator.

The par labeled as IC52 has the following labels:
XL08
4D
6X543

The pictures are attached. On similar board on other monitor, I have found similar circuit and on the PCB was written AKR for legs. On this board, except IC51 and IC52 there are no other labels.

[lotas]

Re: Help to identify IC51 and IC52 on PSU board

IC52 - Xl0840
IC51 - TL431

[Adenitz]

Re: Help to identify IC51 and IC52 on PSU board

I suspect that this IC52 could be thyristor XL0840
https://www.digchip.com/datasheets/p...XL0840-pdf.php
but it doesn't make sense, according to the datasheet it is for 400V!?

[Adenitz]

Re: Help to identify IC51 and IC52 on PSU board

Thank you lotas, much appreciated.

[R_J]

Re: Help to identify IC51 and IC52 on PSU board

I suspect that this IC52 could be thyristor XL0840
https://www.digchip.com/datasheets/p...XL0840-pdf.php
but it doesn't make sense, according to the datasheet it is for 400V!?

It can only handle 800ma so it is likely what the part is.

[redwire]

Re: Help to identify IC51 and IC52 on PSU board

It makes sense as SCR XL0840 for over-voltage protection circuit, I can see the zener in series with the gate.