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Old 09-13-2021, 08:56 AM   #51
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Default Re: xbox 360 blowing mosfet

Originally Posted by risting View Post
I need help for jasper motherboard i read the nand 256mb without problems, damn my bad luck when start on standby mode coolrunner i is on red light after 15 sec coolrunner is off and never again wont on, no red light anymore when connect again adapter is on yellow light when connect to xbox immediately adapter go to red light before rgh console works perfectly adapter if disconnected on power back is on yellow light again when connect to xbox go to red light, i found one mosfet on motherboard short to ground see on the picture maybe smd capacitor i don't know both legs i have beep on multimeter i no remove jp and c8 capacitor !
The component circled in red is not a MOSFET, but rather a 3.3V regulator (LM1117-33 or equivalent, if I remember correctly.) It takes 5V standby power from the power adapter and converts it to 3.3V standby, which is then used by (H)ANA chip, SB, and I think a few other low-power ICs. It also feeds into the 1.8V standby regulator to the left of it (LM1117-18 or equivalent, IIRC.)

So if that 3.3V regulator is not outputting 3.3V on its left-most leg, you either have some other component shorting the 3.3V standby rail or that 3.3V reg is bad (unlikely.) Since this seems to have happened after reading the NAND, I would suggest to check all work that you have done, and particularly look for any solder bridges or damaged components that you might have caused in the process of modding.

Again, on a normal working Xbox 360 motherboard, you will see 3.3V and 1.8V standby from those two regulators as long as the power adapter is plugged in the wall.
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