MOSFET replacement cross-reference

I'm looking for a replacement for this mystery-meat part from a major mfgr on Mouser/Digi-Key, used in a synchronous buck

Not too much that matches exactly, with the low Vgth and all, this is what I come up with so far:

It seems mfgr cheap out on synchronous buck, use third driver transistor instead of driver IC. Mfgr cheap out on transistor, too. It go kabloeey.

Reply to
bitrex
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That's a pretty damn good match, I'd say.

Qg is somewhat lower too, which may mean more room for choosing an even lower Rds(on) part. That depends on if it's the cheap transistor or the cheap controller that caused death...

Tim

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Reply to
Tim Williams

Good deal, thank you. The failure was on a hand-me-down PC I use for audio recording in the spare room. An MSI motherboard on another AMD-based system several years old. The original owner had put a water-cooling block on the processor with a radiator block and fan on the back which works well enough when it works. However...something got altered in the BIOS and the water block pump stopped turning - it was plugged into the 4-pin CPU_FAN header and the cooling fan into SYS_FAN rather than vice-versa.

That naturally caused the CPU temp to start shooting up quick when turned on and dissipating powers it probably never had in its poor life and hitting 90, 95 degrees C and going into thermal shutdown before I noticed what was going on. Also the original owner naturally put the beefiest, highest TDP processor this motherboard claims to support on it.

I got that issue sorted and thought all was okay but the next turn on mobo goes POP! and system shuts down. I thought for sure something had been blown off the board but on close inspection the motherboard looked superficially fine, it took hunting with good light to find the probable culprit:

small chunk is blown off the top, subtle burnt smell around that area too. A google search shows some other users have had this same failure with this particular series of mobos so I'll at least give swapping this MOSFET a shot. Can't find any other signs of damage on the board so far.

Reply to
bitrex

That part seems to work fine as a replacement, clipped and desoldered the popped one put the new one in place and the mobo was back up in 10 minutes. you have to be a real JERK to toss a $200 mobo over an 85 cent blown mosfet and call yourself an engineer!!!

Instead of trying to replace them all (there are about ten total on this brand on the board and some are in pretty tight spaces) I think I'll just thermal epoxy some copper DPAK heatsinks to the rest to hopefully keep them a little cooler under stress...

Reply to
bitrex

or the

would a cpu fan keep them cooler by any chance?

NT

Reply to
tabbypurr

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