G73-SW Freezing at random, missing thermal pad the culprit?

I recently RMA'd my G73 to Asus to have video-card issue fixed. Once I got my laptop back, it started freezing at random times and playing a buzzing noise through the speaker. It would turn completely off if I unplugged the AC power cable (even with fully charged battery installed). I updated all my drivers and any software thing I could think of but it still froze.

I went to replace the RAM under the keyboard, but when I took it apart I noticed it was missing the thermal pad between the top case and this chip (circled in red).

What exactly is this chip and if it were overheating (due to lack of thermal transfer to the laptop case) would it cause my computer to freeze up? I have a new thermal pad on order but I just want to get an opinion on if this is the problem.

 

That would be the northbridge. Pretty important and definitely could cause problems if overheating. Other than that I can't really help you further as I sold my G73JH a long time ago.

 

You can use thermal paste to see if it can resolve this issue, however if problem persists then you may need to inspect other possible cause of issue.
If problem persists, then contact ASUS as soon as possible for a 2nd RMA and prepaid shipping label due to their mistake.

 

Don't use thermal paste on the northbridge though, it's not thick enough to create contact between the die and the bottom of the keyboard plate. I think the original one on there was a 1 mm thermal pad, but I could be wrong.

 

Yes, if the heatsink is not a direct contact with northbridge then it must be missing thermal pad.
If it's a direct and tight contact then you can either apply thermal paste, or thermal pad.

 

I would recommend a pad for it since the NB does not need massive cooling and it's a lot cleaner and more durable.