Hey all! Firstly, this site is amazing! I've been looking for something like this for a while. I hope I can input some of my knowledge to others as I have quite a bit of experience with laptop motherboards.
I've been working for a PC shop for over 12 months now repairing laptops & consoles at component level so I've learnt quite a bit.
I've been trying to isolate a fault on this laptop board for some time now.
The laptop in question is:
HP/Compaq 6735S
Original fault was a dry joint on the DC socket. I've been trying to get this laptop (buy it) off my friend for ages. Since then he's had "Someone who knows about computers" have a look at it.
Anyways, I've got it now. No power, not even from battery. I've stripped it down and traced the input voltage around the board to various areas.
I've resoldered the DC socket & also replaced a LM393 which was burnt. Still not getting any charge/power LEDs.
Whilst 'probing' I felt a hotspot with my hand - TPS51120 - Synchronous Buck Controller (charge controller) This IC gets HOT as soon as power is inserted.
From looking at the datasheet, it seems that this IC is is responsible for charging the battery and switching to AC when charged (duh!)
My first few tests had me checking the surrounding caps - 1 short
I removed the shorted Cap and still have a short across the pads which to me indicates the IC is damaged - hence the heating up
I have seen a number of laptops with similar problems ESPECIALLY after having a bad DC socket. The constant switching of the power supply (Charger making contact, then breaking) over a space of time slowly burns out these controllers until either the battery refuses to charge, or the laptop refuses to power up.
What I'm asking is has anyone else had this problem? What/how did you repair it? This isn't MOSFET or TRENCHFET related
I can upload pictures if needed.
Thanks!
I've been working for a PC shop for over 12 months now repairing laptops & consoles at component level so I've learnt quite a bit.
I've been trying to isolate a fault on this laptop board for some time now.
The laptop in question is:
HP/Compaq 6735S
Original fault was a dry joint on the DC socket. I've been trying to get this laptop (buy it) off my friend for ages. Since then he's had "Someone who knows about computers" have a look at it.
Anyways, I've got it now. No power, not even from battery. I've stripped it down and traced the input voltage around the board to various areas.
I've resoldered the DC socket & also replaced a LM393 which was burnt. Still not getting any charge/power LEDs.
Whilst 'probing' I felt a hotspot with my hand - TPS51120 - Synchronous Buck Controller (charge controller) This IC gets HOT as soon as power is inserted.
From looking at the datasheet, it seems that this IC is is responsible for charging the battery and switching to AC when charged (duh!)
My first few tests had me checking the surrounding caps - 1 short
I removed the shorted Cap and still have a short across the pads which to me indicates the IC is damaged - hence the heating up
I have seen a number of laptops with similar problems ESPECIALLY after having a bad DC socket. The constant switching of the power supply (Charger making contact, then breaking) over a space of time slowly burns out these controllers until either the battery refuses to charge, or the laptop refuses to power up.
What I'm asking is has anyone else had this problem? What/how did you repair it? This isn't MOSFET or TRENCHFET related
I can upload pictures if needed.
Thanks!
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