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caheyne

macrumors newbie
Original poster
Feb 12, 2014
5
0
Amsterdam/Fruitland Park
What can be wrong on a 4.1 tray? It's only on the CPU B side. It's not the CPU, swapped several times. It's not the memory, swapped as well. With another tray everything is fine. I know this tray has been sitting in a computer who ran hot, it killed the CPU B, replaced it, but something else is damaged as well! What can it be? (it runs fine with only CPU A in it) I have several trays, they all run fine, except this one!
No red diagnostic lights btw!
 

startergo

macrumors 603
Sep 20, 2018
5,022
2,283
What can be wrong on a 4.1 tray? It's only on the CPU B side. It's not the CPU, swapped several times. It's not the memory, swapped as well. With another tray everything is fine. I know this tray has been sitting in a computer who ran hot, it killed the CPU B, replaced it, but something else is damaged as well! What can it be? (it runs fine with only CPU A in it) I have several trays, they all run fine, except this one!
No red diagnostic lights btw!
Broken, bent or shorted pins on socket B pins?
 

Slash-2CPU

macrumors 6502
Dec 14, 2016
404
268
Burned out VRM. The CPU heatsink also cools the CPU voltage regulator FETS. If the CPU baked, it’s likely these are toast as well.
 

Slash-2CPU

macrumors 6502
Dec 14, 2016
404
268
Is there a way to check that and/or to repair this?

I’m sure that someone could replace the FETS and any other overheated, failed parts. Swapping them would be the test. It’s probably cheaper, faster, and easier to buy a used board from eBay than repair that one.
 

caheyne

macrumors newbie
Original poster
Feb 12, 2014
5
0
Amsterdam/Fruitland Park
I’m sure that someone could replace the FETS and any other overheated, failed parts. Swapping them would be the test. It’s probably cheaper, faster, and easier to buy a used board from eBay than repair that one.
ordered a board for $350, arriving next week. I'll see if I can replace the FETS on the old board so I'll have a spare one. Thanks for the reply!
 

Slash-2CPU

macrumors 6502
Dec 14, 2016
404
268
ordered a board for $350, arriving next week. I'll see if I can replace the FETS on the old board so I'll have a spare one. Thanks for the reply!

$350? Ouch. You can buy whole used trays off eBay for less.

Edit. Nope. Never mind. Looks like the prices have come up a bit.
 
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