Black screen and no POST until PC's reset

I've been having problems with my PC since a friend fitted a new CPU cooler for me (whether its connected to the problems.. no idea).

1) Occasionally - usually if cold-booted - when the PC is turned on, it just comes up with a black screen and no POST beep. This lasts until you press the reset button, and the PC resets and boots, POSTs, etc as normal.

2) I've been getting very brief pauses/stutters, and momentary rainbow colour flashes when running games, usually when first loaded or reloaded.

Help appreciated!

My specs:

Athlon XP 2000+
Abit KV7-V Motherboard
512 Mb DDR Ram
Geforce4 MX 420 64 Mb
Soundblaster Live 5.1
Seagate 120Mb HDD

 

If it was working fine before the new heatsink my only guess is that the cpu is not seated properly.You will have to take the heatsink off and make sure you clean off the processor with some isopropyl alcohol at least 91% or greater which can be purchased at you nearest drug store,also use a lint free cloth, Reseat the cpu and apply about a small grain size of thermal paste spread around only on the cpu die (the metalic rectangle) on the cpu and re apply the heat sink and see if that works.

 

Well, I've discussed it with my friend, and he says he didn't remove the CPU when the CPU cooler was fitted, that its a lever locked socket etc etc.

His suggestion is that the PC being moved about and opened up, etc has caused a glitch with the BIOS chip when its cold, as it works ok when warmed up a little... Which is reasonable, but doesn't explain the stutters.

*However* I notice when I get these odd pauses, the CPU fan speed changes for a second, then returns to normal... whether that means anything..?

Note: I am disabled and its incredibly difficult for me to physically remove the cooler or CPU without risk of damage. So I'd like to be pretty sure of what the problem is...

 

First thing is to make sure everything is plugged in firmly. Drives, cpu fan . Make sure memory and vid card are also seated. Maybe when replacing the heatsink something got jarred loose. When it boots, what temps are you running. A high temp would indicate that the heatsink is not installed properly like Jamcgiff said.....just some thoughts. SM

 

I tend to agree with jamcgriff! If your CPU cooler was replaced, and the problems began then, then his suggestions are where I would look first. Your friend may be correct that the CPU socket is levered, etc., but your symptoms sound processor related. If the stock cooler was removed, the top of the CPU should have been cleaned with alcohol, and a suitable heat dissapating compound such as Artic Silver applied before applying the new cooler.

Please ask your friend if he did this, as a lot of the stock CPU coolers that I have seen have a thermal cooling pad attached to the bottom of them, and the residue left by this could be a problem.

As for moving the computer around and opening the case causing an issue or problem with the BIOS chip, I kind of doubt that one, because if there was a BIOS issue, then you wouldn't be able to boot. Hope this helps!

 

Thanks.

Well, my temperatures are *usually* ok. 30c idling, 46-50c under load. *But* I've been seeing occasional temperature spikes (of 5-10c) just surfing online.

The new CPU Cooler had silicon thermal compound pre-applied. My friend wiped off the old (Antec Silver) thermal compound from my CPU before fitting it.

However... not with alcohol, just wiped off.

Temperature spikes = bad compound mix and odd CPU behaviour?

And yeah, a slightly temperamental BIOS chip sounds a little too pat. It might explain a blank screen and no POST, but surely the reset button wouldn't work with no BIOS?

I'm going to ask if he'll take a look, We'll remove the cooler and CPU, go over the socket with a magnifying glass, etc and clean everything properly. Then apply a little Antec Silver again. My friend is one of those guys who tend to use a big blob of compound, so I'll have to restrain him :-/

 

Right.

We removed the CPU and Cooler and cleaned them with isowhatsit alcohol, only a *very* slight residue left on the CPU which we couldn't get (terrible messy crap).

We re-applied a minute amount of Antec Silver, as per its packaged instructions. Checked the Motherboard and CPU socket - no problems found.

Unfortunately, when cold-booting, I'm still having a few problems... crashing or complete lockups in Windows (XP Home and 98 FE). Haven't had a no POST again - yet.

CPU temp has improved. No overheating problems, max temp so far 47c, obviously that'll take a week or 2 to settle down.

All hardware and connections checked. No problems found.

A possible Motherboard or Processor fault?

 

*Sigh*

Testing stability with Hot CPU Test Pro 4:

000073| 9999 fff9c9a7 Mar, 22 - 20:35:04 | Error:CPU 0: Checksums do not match; Matrix1 = -1.#QNAN0, Matrix2 = -28115503930.188995

CPU temp 47-48c.

Dodgy CPU?

 

I';m just thinking aloud here ... but could it be possible that the mobos header that supplies current to your fan isn't enough to keep the fan running?

 

No, I've checked it... its just a standard 3-pin 12v.

Checked over everything, especially the CPU Cooler and connections.

*If* its a hardware problem, I'm pretty certain its the CPU or MB.