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Do I have a bad CPU? tried new mobo and PS, no help... 1

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stevenriz

IS-IT--Management
May 21, 2001
1,069
Hi all, the computer turned on but no boot and no video. I tested the PS and found it was ok so I assumed the mobo cooked. it's an old emachine. got a replacement mobo and the machine had the same symptoms. swapped out the PS and still, the same symptons. I tried each combination of the both mobos and both PSs to no avail.... it's unlikely but it is possible the new mobo and PS are bad too...

does anyone think the CPU cooked? I don't get any message or beep codes. It's an Amd sempron 3300+ 2ghz 1600mhz 128kb... thoughts?

thanks!
Steve
 
If MB uses a video card, then replace it. If the MB uses an onboard video adapter, then either the RAM or the CPU may be bad(Yes, I've seen bad RAM that did not produce a beep code).
 
thanks for the tips. both mobos have onboard video. can't even get bios screen to disable that.... so since I have extra ram at home, I will pick up a CPU.

Steve
 
Things to try:

unplug mains (powercord) from the back of the PC. Hold down the POWERBUTTON for a minute or more, this resets the PSU, as some PSUs out there have a safety feature that will not power a mainboard once tripped...

check the HS-FAN, if it is plugged into the correct header... most mainboards will not power up if they detect a missing or damaged HS-FAN...

unplug the IDE/SATA cable from the mainboard... I've seen HDD's and cables cause the same symptoms...


Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."
 
Buying a new CPU for an old Emachines PC is like...well, putting lipstick on a pig. A waste of money and time. A $49 modern mainboard will slaughter it, wait until you can afford to upgrade everything...OK, you can keep the CASE[smile]

Tony

Users helping Users...
 
good idea Wahnula... I will consider!
 
When you are checking for boot on these two different motherboards and PSU's are you leaving everything else connected?
Chances are (we are talking eMahines) that the PSU has taken out something else, usually hard drive or CDrom and if left connected they are preventing BOOT.
Bare bones....Motherboard/CPU/Cooler/Ram/PSU and when I say bare I mean pull out everthing ie; front panel connectors, IDE cables, all molex power cables to CDroms/HDD's, any addon cards.
BARE BONES
Use a small flat blade screwdriver across the pwr (power) pinouts on the motherboard (touch for a moment)
Yes....I know...it posts doesn't it?
LOL
WELL I'd be suprised if one of the combinations didn't post, CPU's are normally the last thing to fail in an eMachines.
Martin

On wings like angels whispers sweet
my heart it feels a broken beat
Touched soul and hurt lay wounded deep
Brown eyes are lost afar and sleep
 
thanks again for the tips.

ok I replaced the mobo, PS and cpu. I still can't get a post. I did the screwdriver trick and it turns the machine on but no post. no cards installed. no drives. even tried it without the memory. cleared the cmos on both boards too. I just don't get it. I must have burned something else out is all I can think of. I've built and fixed many many computers... this one has like some ghost in it....
 
Graphic card...

reseat the graphics card, if that does not work then get one that is known to work and try it...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."
 
on these mobos, the video is on board. let me see if I Can find a video card around here and try that. I'll swap monitors out too, at this point I'll try anything. it's a challenge now.
 
if you have a multimeter, then check the outlet and see if it is delivering enough voltage in the first place...

e.g. in the US it is standard between 110v and 120v (regional differences included, I've been to places where the power was 115v (Arizona) and 120v (Georgia))... and if the voltage is below 100v, lights and some electric equipment will still work, but the PSU in a PC is not getting enough power to convert and will not power the mainboard correctly...

also check if you have too many electronic devices attached to the circuit, which could cause a brown out...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."
 
I do have a power supply tester which reads ok on both power supplies I have here.
 
Take the board out of the case and with just power, cpu and cpu fan and ram installed short the power pins and see if it posts.
 
Tlscousin, that is a good suggestion, and is the next logical step here...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."
 
I've lost it....

mobo out of the case. CPU, CPU fan, memory and power supply. tried every combination of both CPUs, both power supplies and two sticks of ram. the cpu fan comes on and the monitor light goes from amber to half amber half green. no post on either mobo... two bad boards/CPUs or both?
 
try one stick of ram and if no post take that one out and try the other.
 
yup did all that as well... cleared CMOS on both mobos too!!

I might just have to buy another mobo and CPU. the memory I know is good, just tried it in another computer. both power supplies are good too.... tested them... maybe even a new CPU fan although it seems to be working fine...
 
after having tried all that you did, it can be dead mobo's or the CPU involved are not compatible with the BIOS version...


Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."
 
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