Unsolvable? Please help!

[Primus]

I think I may have localized the problem being with cpu overheating, but why? Here's the situation: BRAND NEW system - mobo+cpu+RAM combo bought together, rest separates.
DFI-AK76 mobo (DDR 266FSB etc)
AMD 1.33G 266FSB cpu (AYHJA)
Tai-sol heat sink (CGK742092)
Sparkle 350W PS
256 MB PC2100 DDR RAM
ATI Radeon 64 M video
IBM 40G 7200 HD
Plextor 16/10/40
(I have removed all other cards etc.)

On first assembly, could not complete installation of Win2K, Win98 or ME at all (random errors, BSD etc). Then turned off all internal caches in BIOS, took 3 hrs, but installed win98. Turned on caches, tried optimized/fail safe/normal defaults in BIOS, errors again. Cleared CMOS, flashed to latest BIOS, replaced RAM with a new stick (Kingston), changed video card to an ATI Expert 8 MB, still crashes, reboots, BSD etc. RTFM of the mobo, thought
what the hell, changed the mobo CPU-FSB jumpers from 133MHz (266DDR)to 100MHz (200MHzDDR), which is the mobo default. The dip switches SW1 and SW2 are on auto setting. BINGO! Everything works! However, the cpu now shows up as running at 1000MHz on boot up, the utility cpuinfo from AMD and Sandra also show it to be 1000MHZ. Funny, on the occasions that the system did boot up with the jumpers at 266MHZ, the cpu also shows up as 1.33GHz. Careful exam of the cpu reveals it is indeed a 1.33GHz AYHJA chip. So what is going on? I then looked at the cpu voltage and temps. Here's the problem, as I see it:

With jumper at 100MHz (200DDR):
Core temp steady at 35 for several hrs.
Vcore = 1.77
2.5V = 2.58
3.3 = 3.3
5V = 5.07
12V = 11.82

With jumper at 133MHZ (266DDR):
core temp shoots up to 50 within 10mts
Vcore = 1.78
2.5V = 2.58
3.3 = 3.28
5V = 5.05
12V = 11.88

I checked the heat sink and cpu, the thermal paste is dry, there doesn't seem to be anything between the heatsink and cpu core. The placement however, is OK (removed and replaced it myself - carefully!)

So, why does'nt the system work the way it should? Is it the heat? If so, why does the cpu heat up so much in an AC room with the case open, case fans blowing away (I have an extra), heatsink of reasonable quality, good power supply, and all settings as they should be. Please help, I am going crazy.

[Reid]

I think the 50C temp is OK. My Athlon 850 runs at 46C with a ThermoEngine heatsink and three case fans. If the thermal paste is dry, it may be phase-change compound and should be removed and replaced with a good quality paste, since the heatsink has been removed.

It sounds like your memory does not handle the 266 MHz. There may be some BIOS settings that may help, but I'm not familiar with DDR.

------------------
reido@my-deja.com

Friends don't let friends install Windows ME

[Primus]

Thanks. I got the Radio Shack thermal paste and sure enough, the cpu temp is now steady at 46. However, still it crashes or reboots and only works like a charm if underclocked down to 1.0GHz.

The mobo seems fine, the PSU is very good, cpu is not overheating, so is it the memory? I tried two different memory chips, from Kingston (value RAM) and a Samsung that was supplied by the vendor, both 266 FSB chips. Should I spend the extra money for Crucial RAM and try that?

Changing settings in BIOS may make it run but not at optimum speed, which was the whole point of buying state of the art. Any suggestions?

[Reid]

I have had to bump the memory speed down a bit on systems with SDRAM, but unfortunately, you can only take one big step. I have not used DDR, so I don't know what tweaks may help. You could check this BIOS Guide (http://www.rojakpot.com/Speed_Demonz/BIOS_Guide/BIOS_Guide_Index.htm) and see if there is something that might help.

------------------
reido@my-deja.com

Friends don't let friends install Windows ME

[Paleo Pete]

Don't know of any real solutions, but some info that may help. Check mjc's topic Extra Crispy Athlons (http://www.pcguide.com/ubb/Forum8/HTML/000386.html), he got some info from AMD that indicates you should use phase change thermal tape rather than thermal paste or standard thermal tape.

mjc and I also discussed the AMD issues we've seen while we were on IRC a few nights ago, and it seems he's noticed (and I agree) that a majority of the problems we've seen with AMD chips also involve VIA chipsets.

With the problems you're describing I would try using standard SDRAM and see if it makes a difference, otherwise I don't have any other worthwhile suggestions, other than trying a motherboard without the VIA chipset, which might not be a possibility.

Also double check and be sure the voltages are all correct. CPU or memory voltage could be affecting it.

Another observation, with the case cover removed, the power supply and case fans are not really performing as they should, they are designed to pull air through a closed area, and without the cover on it's now an open airspace, so the fans cannot pull air across the heatsink and other components, although the A/C should help.

I don't think this is a major issue, with the CPU temps you posted, but thought I'd add it so people will be aware that removing the case cover drastically changes the effectiveness of the fans. If you remove the case cover and even think you might have heat problems, be sure and place a small fan where it can move plenty air through the case, since the existing fans can't do it without the cover on.

------------------
Support the right to keep and arm bears.
Note: Please post your questions on the forums, not in my email.

Computer Information Links (http://www.geocities.com/paleopete/)

[Dinosaur]

50 Fahrenheit is OK: That is a chilly day for some, comfortable for others, and wonderful for a CPU. 50 Celsius is too hot for a CPU: That is 122 Fahrenheit, which is normal at noon on a hot day in Death Valley or the Sahara desert.

At 50C, your CPU will fry PDQ.

------------------
Gouverneur
Eschew Obfuscation!
If one hundred million people believe a foolish idea, it is still a foolish idea.

[mjc]

Not to open the whole debate again but, basically AMD calls 50°C the upper end of normal operating temp...

Basically I like to see temps in 35° to 45° C range, but 50° isn't going to do it in that quickly.


------------------
mjc
Links list:Computer Links (http://www.dreamwater.org/tech/mjc/index.htm)

Celts are the men that heaven made mad, For all their battles are merry and their songs are all sad.

[Gallaeglagh]

Just a general observation here - I've noticed reading this board that there seems to be a quite a few individuals that seem to have problems with AMD processors yet almost none with P2,3 or 4s

------------------
Your attempt to reach civilization by fashioning a crude raft will astound everyone else at the office. - The Onion

[mjc]

There is one other area that could be a heat related problem...the memory could be suffering from heat...there are several heatsinks available for it. I haven't seen much on this but to me it stands to reason if you OC something the temp will go up (and what DDR is is basically OCed memory, yeah...get fancy and explain it as "double pumping" or whatever, but you are putting twice as much data through on each clock cycle...looks like OCing to me) and if the temp increases too much, problems will occur.

------------------
mjc
Links list:Computer Links (http://www.dreamwater.org/tech/mjc/index.htm)

Celts are the men that heaven made mad, For all their battles are merry and their songs are all sad.

[kalifaye]

i don't know if this will help you but my friends and i have had crashes and bootup problems using ati video cards with via chipsets...
http://www.PCGuide.com/ubb/frown.gif

------------------
Rule 1: The computer is always right.
Rule 2: If you think the computer is at fault, see rule 1.