HP G71 temps widly change

[Uranium-235]

So got this top to work on, was for a friends friend so I decided to clean it out, it was bug bombed and a bunch of roaches were inside it. All dead, though. Not as bad as another asus ROG laptop I worked on some time ago that was just full of live ones

aaanyhoo I decided to upgrade the PDC T4300 to a china bought T8300 Penryn-3M

updated the bios ahead of time. Saw it fine. Cleaned some real full junk from the heatsink that was 100% covered with a mesh of dust, dirt, dog hair, and cockroach bodyparts

fan was bad, replaced that too

got it all ready and the fan ran pretty much all the time either very low, or very high

hwmon was giving me these crazy temps. at idle, it was about 29c, with fair >50% activity, it jumps to ~70-100c on both cores, and quickly drops back down

the heatsink was put on, after cleaning both sides with 90% isoprobyl, with a thin nice layer of arctic silver 5, like I do with just about all cpus

is the thermocouple bad? is the CPU bad? because of the bad fan it was hard for me to tell if it was doing with the clogged heatsink

is the heatpipe bad? I've never encountered such odd fluctations. Usually with laptops I see either normal temps or solid medium-high ones.

[diif]

Re: HP G71 temps widly change

Swapping back to the original CPU should eliminate that as the cause.

[piernov]

Re: HP G71 temps widly change

Usually if they spike by more than 15°C in less than couple of seconds when applying some load, there is an issue with the heatsink. Not making good contact with the CPU, broken heatpipe or just clearly undersized and saturated so it cannot dissipate any additional power.
But it can always be a software issue reporting wrong temps, so try to cross-reference with other software.
CPU itself reporting wrong temp could happen but that'd be very rare. You can still try to put the original CPU back to exclude that possibility as @diif said.

[Uranium-235]

Re: HP G71 temps widly change

Yeah found the problem. Put the original cpu in. Worked fine. Put the new one in, also worked fine. Put it back together. Problem again..

Some nutsack made this heatsink assembly so the cpu plate is pushed down with four springs. I would push fan/fins flush and it would wind up in post. I just spent two hours with just the motherboard in the base frame pushing it down, taking the board out, bending the fins a little, and bending the pipe a little, trying to watch the plate from under the chassis move when I pushed down, listening to the fan spin up or down. This is a terrible design. Why not just bond the fucker to the assembly like everyone else does?

Found a pic with a good angle. You see this shit?

[Uranium-235]

Re: HP G71 temps widly change

I had to test the damn thing so many times last night and make small adjustments, unplugging the power button so many times, it wore the ffc. When I was going to put it together for the final time today the blue label fell off and it won't stay down. So now I gotta get the button board for it as I can find no ffc at mouser thats 16mm/1mm pitch/10 contact

[piernov]

Re: HP G71 temps widly change

Larger cable and cutting the excess pins would work too.
If it's just the blue tab and the pins themselves aren't broken, glue it back or use a piece of cardboard to keep the cable in place in the connector.

[Uranium-235]

Re: HP G71 temps widly change

I just checked mouser and the closest 178mm, even at different number of contacts us unavailable (not stocked)

If it's longer I can just bend it but still