PCH heatsink on GA-H61MA-D3V

[emueyes]

Hi all

I normally check the mounting of any stock heatsink on a new board, just to make sure things are OK. Recently I put together a system based on a GA-H61MA-D3V in a bit of a hurry. Today, though, I found an old Zalman southbridge, the one with the square pins and movable arms for pushpins, and had a bit of spare time, so I decided to have a look, as the stock hs was getting quite hot.

The attached pic is the heatsink. The TIM pad is untouched, unmelted, and the top of the PCH flipchip was clean glassy silicon. I'm totally at a loss to explain this. The heatsink isn't concave, held against a steel rule, my first thought. So, how did it get hot? Why didn't the PCH overheat? 

The Zalman sink gets lukewarm and I'm sure DOES touch the chip, from the heatsink compund pattern when I applied it.

I've seen odd stock thermal compounds before, but this is a new one.

[Dark Mantis]

Hi

A new one on me too to be honest. I can't imagine a scenario whereby the heatsink floats in mid air above the chip without touching it.

[emueyes]

The only scenario I can see is that the PCH is seriously concave, didn't touch the heatsink, and got so hot that radiant energy alone heated the heastsink. That doesn't sound very plausible though. I didn't think to check the flatness of the PCH, though it mated perfectly with the Zalman sink, which dates back to the days when I spent hours lapping heatsinks. So I'm presuming it's OK,  a few years in the spares cartons doesn't seem to have hurt it.

I'd be interested to see if any other D3V boards, or any others that use the same hs are like this.

Another mystery, which may be able to be solved, is the fact that the H61 PCH temps aren't collected / displayed by HWInfo64 v3.95