Homebuilt Computer Won't Power Up

[Peter S.]

I've built 3 PCs at home with no problem, but now I'm stumped.

I wanted to put together a fourth box - so I got a new motherboard and a
new case. Bottom line: when I first tried to power up - the CPU fan
would spin but I'd get no video, no post beeps, or anything to indicate
what the problem was.

The problem has further progressed to where the PC won't even go on -
the power light flickers but that's about it.

I have tried using the same mobo in several different cases.

I even used another known working motherboard.

I swapped out various components (video, memory, power supplies).

I considered that the motherboard and/or CPU could be fried, but there's
been nothing to indicate that and I did try a different board. When I
got the new board I used a CPU that I had, so maybe THAT could be the
problem - but I figure it would still power up.

Never had a problem like this! I'm stumped. Any help appreciated.

The board is a Biostar P4TSE-D2. The chip is a Pentium 4 2.6 ghz.

Peter

 

[JAD]

Different MoBo in the original case /w Power supply and its dead? Different
CPU also? Power supply is bonkers

 

[jaster]

I've built 3 PCs at home with no problem, but now I'm stumped.

I wanted to put together a fourth box - so I got a new motherboard and a
new case. Bottom line: when I first tried to power up - the CPU fan would
spin but I'd get no video, no post beeps, or anything to indicate what the
problem was.

When CPU fan spins I don't think its the power supply but the power supply
could under powered for your new system. You need to check the power
output specifications.

The problem has further progressed to where the PC won't even go on - the
power light flickers but that's about it.

I have tried using the same mobo in several different cases.

Did anything work?

I even used another known working motherboard.

Did it work ?

I swapped out various components (video, memory, power supplies).

Return to seller as defective merchandise. You didn't say which items
worked or didn't work when you swapped various components.

I considered that the motherboard and/or CPU could be fried, but there's
been nothing to indicate that and I did try a different board. When I got
the new board I used a CPU that I had, so maybe THAT could be the problem
- but I figure it would still power up.

Never had a problem like this! I'm stumped. Any help appreciated.

The board is a Biostar P4TSE-D2. The chip is a Pentium 4 2.6 ghz.

Intel CPUs are really stable and hard to kill on boot unless physically
damaged like broken pins. Even so Intel is an honorable company and will
exchange the CPU if it is damaged especially a boxed CPU.

 

[km]

The problem has further progressed to where the PC won't even go on -
the power light flickers but that's about it.

I swapped out various components (video, memory, power supplies).

I considered that the motherboard and/or CPU could be fried, but there's
been nothing to indicate that and I did try a different board. When I
got the new board I used a CPU that I had, so maybe THAT could be the
problem - but I figure it would still power up.

I am no expert but my suggestion:

I had built a number of systems but the latest one I put together
would not boot up even though I had done everything as normal.

It crossed my mind that I had a bad motherboard until I realised that
this latest one required the small (square) power connector to be
fitted from the PSU to the motherboard. Everything was then OK.

This may seem obvious to a lot of Newsgroup participants but it was my
first experinece of the need for this additional power connection.

Maybe your problem is as simple.

KM

 

[fj]

I've built 3 PCs at home with no problem, but now I'm stumped.

I wanted to put together a fourth box - so I got a new motherboard and a
new case. Bottom line: when I first tried to power up - the CPU fan would
spin but I'd get no video, no post beeps, or anything to indicate what the
problem was.

The problem has further progressed to where the PC won't even go on - the
power light flickers but that's about it.

I have tried using the same mobo in several different cases.

I even used another known working motherboard.

I swapped out various components (video, memory, power supplies).

I considered that the motherboard and/or CPU could be fried, but there's
been nothing to indicate that and I did try a different board. When I got
the new board I used a CPU that I had, so maybe THAT could be the
problem - but I figure it would still power up.

Never had a problem like this! I'm stumped. Any help appreciated.

The board is a Biostar P4TSE-D2. The chip is a Pentium 4 2.6 ghz.

Peter

I had virtually the same symptoms just recently. The CPU and Power Supply
fans would start - run for a few seconds, then the power would shut off.
The, the two fans wouldn't even start [which was 'fixed' by turning the
mains off/on]
While this doesn't make sense to me, the rig powered up right after
reseating the heatsink on the CPU. I can only guess that the CPU temp was
exceeding the max/stable temp within the first few seconds without the
heatsink being attached.

 

[w_tom]

You are using shotgunning for a solution. Therefore you are
wildly speculating. Good PC builders break the problem down
into parts; and then solve each problem.

The one item that makes all other subsystems look defective
is the power supply system. And so you have a another tool as
important as the screwdriver - sold even in Sears, Lowes,
Radio Shack, Home Depot, and WalMart. A 3.5 digit multimeter.

The voltage on gray, green, and purple wires is particularly
important. What are these voltages when you first attach a
power cord, turning the time your press the power button, and
after the power button is released? And after the power
button is released, what is the voltage on red, orange, and
yellow wires? With numbers, we waste no time wildly
speculating, swapping parts (shotgunning), or posting to
others who cannot provide any useful information (because they
have no numbers).

Details on how these numbers are obtained (in less than 2
minutes) are previously posted at: "Computer doesnt start at
all" in alt.comp.hardware on 10 Jan 2004 at
http://tinyurl.com/2t69q
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://www.tinyurl.com/2musa

Pictures to help you see what is described are:
http://techrepublic.com.com/5102-10586-5566528.html
www.ochardware.com/articles/psuvolt/psuvolt.html

Even if you don't understand what those numbers say, well,
now you have facts that will attract those who really know how
a power supply 'system' works. Yes - 'system'. Power supply
is only one part of that 'system'. Just another reason you
need the meter. Swap a power supply and still have a
defective 'system'? How would you know given what others have
recommended? Instead break the problem down into parts.
Verify integrity of the power supply 'system'. Once
confirmed, only then are you ready to move on the the next
part - the next usual suspect.

 

[Peter S.]

I'd have to say "guilty as charged"! I'd never had a problem like this
that I couldn't solve, but obviously this isn't one of those times. I
shall try your solution and I do thank you for it.

 

[w_tom]

It is why we build things - get dirt under the fingernails.
Without that dirt, then your boss also could not help you;
which is why the boss also must have dirt under his
fingernails.

The concept is not intuitively obvious. Breaking a problem
down into parts and then collecting relevant facts. It is
often learned by example - getting your hands dirty.
Congratulations. You finally have an example that is useful
(the rosy side of bad situation).

 

[sdeyoreo]

Been there. Check your PS. Just had to reseat the connector on mine.