ASUS K50AB (ATi) with extensive overheating (two sections)

[inflex]

I have an ASUS K50AB which has the ATi graphics installed. The system overheats delightfully and despite redoing the paste and pads on the cooling assemblies.

The ATi chip still does get fairly hot (80~90'C) and the AMD CPU sits at about 70'C but the fan never kicks in to full speed (other than on power up). It was pushing 110'C before the cleanup (lint removal) and reseating so thing have improved slightly there.

HOWEVER, the thing that is really worrying me is the amount of heat coming from the power/memory corner of the mainboard (top-right when you're using the laptop normally). It's getting too hot to touch almost, so that puts it at about 50'C on the chassis at least. Any ideas what I should be looking for? First thing that comes to mind is dud switchmode caps perhaps, or maybe a slowly failing MOSFET (going high resistance)?

*EDIT: I've upgraded the BIOS to v213 without any notable improvement.

[c_hegge]

Re: ASUS K50AB (ATi) with extensive overheating (two sections)

Has it always run that hot?

[nish_pinto]

Re: ASUS K50AB (ATi) with extensive overheating (two sections)

Are you sure the problem is not the heatsink fan? Maybe you can get the fans to work at 100% speed and check the temperatures.

[inflex]

Re: ASUS K50AB (ATi) with extensive overheating (two sections)

@c_hegge, can't say for sure, because this is a client machine that they basically bought in, it was running way hot to start with and shutting down, now it just runs "moderately hot" and still infrequently shuts down (to be fair, we're in the middle of a 40'C Summer here).

@nish_pinto, might do that, pull out the sense wire and hopefully that'll make it run at 100%.

[inflex]

Re: ASUS K50AB (ATi) with extensive overheating (two sections)

Full fan speed drops the CPU down to 47~59'C, chipset to about 55'C, ATi GPU to 75'C. I think when running Ubuntu 12.10 with non-ATi drivers the ATi chipset increases in temp quite a lot due to inefficient running (seems to run 'full power').

EDIT: The top-right section near the power management part of the mainboard is still getting exceedingly hot. I'm sincerely thinking there's a major inefficiency going on with the switchmode conversion, either cap, diode or mosfet :\

[lord]

Re: ASUS K50AB (ATi) with extensive overheating (two sections)

Try to turn on the laptop with the motherboard out and then try to determine with your fingers which component is hot.
I remember HP mini 2133 case where the CPU was extremely hot, and after the reflow was fine.