Hi all,
Reaching out for any thoughts as I'm stumped.
I have two identical failed laptop motherboards. Both sport an Intel i7-6820hq.
Both boards failed in the same way, just went 'dead' with a smell of burning, not shorting the charger, but the inductors get very hot when plugged in to the laptop power supply.
An obvious failure on both was PU603 (Vishay SIC530 Manual) appearing burnt at the Vin section and Vin showing short to ground.
Removing PU603 removes that short, but I'm left with a short to ground on the Vswh side which the datasheet calls "Switch node of the power stage". I think that connects to the processor?
I cannot find the short and I've pretty much resigned myself to it being the processor.
The first board I did a poor job at removing PU603 so I have essentially consigned it to scrap and dismantled that bit by bit looking for any changes.
On that board I have removed:
PU602, PU605, PU606 (all SIC530), no change.
A bank of capacitors next to PU604 and PU605 that appeared shorted.
PU601
No amount of checking/removing surface mount caps or other chips will lead me anywhere close - the problem is seems confined to any section with components labelled x6xx so I think that's all one related circuit. My last thoughts are the capacitors on the rear side under the processor.
Does anyone have any thoughts? Pictures of the second board with only PU603 removed.
If anyone wants clearer photos of a section, please let me know - I'm struggling with the phone camera.
Reaching out for any thoughts as I'm stumped.
I have two identical failed laptop motherboards. Both sport an Intel i7-6820hq.
Both boards failed in the same way, just went 'dead' with a smell of burning, not shorting the charger, but the inductors get very hot when plugged in to the laptop power supply.
An obvious failure on both was PU603 (Vishay SIC530 Manual) appearing burnt at the Vin section and Vin showing short to ground.
Removing PU603 removes that short, but I'm left with a short to ground on the Vswh side which the datasheet calls "Switch node of the power stage". I think that connects to the processor?
I cannot find the short and I've pretty much resigned myself to it being the processor.
The first board I did a poor job at removing PU603 so I have essentially consigned it to scrap and dismantled that bit by bit looking for any changes.
On that board I have removed:
PU602, PU605, PU606 (all SIC530), no change.
A bank of capacitors next to PU604 and PU605 that appeared shorted.
PU601
No amount of checking/removing surface mount caps or other chips will lead me anywhere close - the problem is seems confined to any section with components labelled x6xx so I think that's all one related circuit. My last thoughts are the capacitors on the rear side under the processor.
Does anyone have any thoughts? Pictures of the second board with only PU603 removed.
If anyone wants clearer photos of a section, please let me know - I'm struggling with the phone camera.
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