Hypertherm circuit board help needed

[jsland]

New to the board, a small plasma cutter owner and looking to expand to a table and larger unit soon. My current problem is with my Hypertherm Powermax 30. It was intermittently turning off after 30 seconds of use, would turn back on if you let it sit, but now will not turn on altogether. The AC power light does not come on at all. Disassembled unit and did some troubleshooting. Found that a small integrated circuit chip has burnt up. The chip is in the U4 position on the board but unfortunately the numbers are not legible on the chip after it fried. If someone has one of these boards laying around and could get me the numbers off the chip, I believe I can repair this board for a few dollars rather than $700 on a new board assembly. Picture is attached with red arrow pointing to location. There is a heat sink attached to the chip. Any help would be greatly appreciated!

[djreiswig]

Maybe this will help.
There is a schematic on the last page.
https://www.hypertherm.com/Download?fileId=HYP104643

[acourtjester]

the schematic does not list the chip ID as to any numbers. from your image is looks small like a 3 legged one. On the attached screen show of the schematic I put a square around 2 voltage regulators. they normally are 3 legged and many have heat sinks attached to them. Their output is most likely for logic voltages. This is a real shot in the dark without really closer look at the board and using meter to ID components near it to clear which it really is. Now another thing is it may been taken out by another component failure drawing high current through it, meaning replacement may just blow again. If in fact it is a regulator. There is a guy who repairs Plasma unit on the web, https://georgesplasmacuttershop.com/

[adbuch]

Now another thing is it may been taken out by another component failure drawing high current through it, meaning replacement may just blow again. If in fact it is a regulator.

That would be my thought as well. I think your best bet would be to contact the online repair shop Tom referenced.
Good Luck!
David