Welcome to PCForumz.com!
FAQFAQ      ProfileProfile    Private MessagesPrivate Messages   Log inLog in

stumped! will not go through BIOS sequence

 
   Hardware Problem Solving Community! (Home) -> Home Built RSS
Next:  "Extra" Drive in explorer  
Author Message
nmcewen

External


Since: Oct 31, 2004
Posts: 2



(Msg. 1) Posted: Sun Oct 31, 2004 6:58 pm
Post subject: stumped! will not go through BIOS sequence
Archived from groups: alt>comp>hardware>pc-homebuilt (more info?)

I have been trying to fix my son's PC. It is like the monitor does not
see the computer. When you turn on a computer, it normally goes thru
the BIOS sequence and shows you what it is doing on the monitor. This
PC does not even do that.
The first thing I tried was a new video card -- no luck.
Then I tried a new motherboard -- no luck.
The BIOS is on the motherboard, so if the mother board and video card
are new, what is left?
I measured all the voltages on the ATX connector from the power supply
while plugged into the motherboard. They all measure about 30% high on
a DVM. Is this indicative?
We unplugged all the ribbon cables, thinking something else was dragging
down the MB -- no luck.
I don't think it could be the CPU, because even without a CPU or with a
bum CPU should'nt it still go thru the BIOS sequence?
I am open for suggestions. Can anyone give me some fresh ideas?
Thanks for any help!

 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
JAD2

External


Since: Aug 18, 2004
Posts: 222



(Msg. 2) Posted: Sun Oct 31, 2004 6:58 pm
Post subject: Re: stumped! will not go through BIOS sequence [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)

They all measure about 30% high on
a DVM. Is this indicative?

that's indicative,,,,5% is allowable but 30 is a out of line. can't
say that its THE cause of your problems but after a MB swap that only
thing really left is the power supply.




"Neal McEwen" <nmcewen RemoveThis @sbcglobal.net> wrote in message
news:P_dhd.9092$bP2.7223@newssvr12.news.prodigy.com...
 > I have been trying to fix my son's PC. It is like the monitor does
not
 > see the computer. When you turn on a computer, it normally goes
thru
 > the BIOS sequence and shows you what it is doing on the monitor.
This
 > PC does not even do that.
 > The first thing I tried was a new video card -- no luck.
 > Then I tried a new motherboard -- no luck.
 > The BIOS is on the motherboard, so if the mother board and video
card
 > are new, what is left?
 > I measured all the voltages on the ATX connector from the power
supply
 > while plugged into the motherboard. They all measure about 30% high
on
 > a DVM. Is this indicative?
 > We unplugged all the ribbon cables, thinking something else was
dragging
 > down the MB -- no luck.
 > I don't think it could be the CPU, because even without a CPU or
with a
 > bum CPU should'nt it still go thru the BIOS sequence?
 > I am open for suggestions. Can anyone give me some fresh ideas?
 > Thanks for any help!
 ><!-- ~MESSAGE_AFTER~ -->

 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
JAD2

External


Since: Aug 18, 2004
Posts: 222



(Msg. 3) Posted: Sun Oct 31, 2004 6:58 pm
Post subject: Re: stumped! will not go through BIOS sequence [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)

you have the speaker hooked up? no beeps?

"JAD" <Kapasitor.TakeThisOut@coldmail.com> wrote in message
news:10oatsl6cro1je7@corp.supernews.com...
 > They all measure about 30% high on
 > a DVM. Is this indicative?
 >
 > that's indicative,,,,5% is allowable but 30 is a out of line. can't
 > say that its THE cause of your problems but after a MB swap that
only
 > thing really left is the power supply.
 >
 >
 >
 >
 > "Neal McEwen" <nmcewen.TakeThisOut@sbcglobal.net> wrote in message
 > news:P_dhd.9092$bP2.7223@newssvr12.news.prodigy.com...
  > > I have been trying to fix my son's PC. It is like the monitor
does
 > not
  > > see the computer. When you turn on a computer, it normally goes
 > thru
  > > the BIOS sequence and shows you what it is doing on the monitor.
 > This
  > > PC does not even do that.
  > > The first thing I tried was a new video card -- no luck.
  > > Then I tried a new motherboard -- no luck.
  > > The BIOS is on the motherboard, so if the mother board and video
 > card
  > > are new, what is left?
  > > I measured all the voltages on the ATX connector from the power
 > supply
  > > while plugged into the motherboard. They all measure about 30%
high
 > on
  > > a DVM. Is this indicative?
  > > We unplugged all the ribbon cables, thinking something else was
 > dragging
  > > down the MB -- no luck.
  > > I don't think it could be the CPU, because even without a CPU or
 > with a
  > > bum CPU should'nt it still go thru the BIOS sequence?
  > > I am open for suggestions. Can anyone give me some fresh ideas?
  > > Thanks for any help!
  > >
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
David Maynard

External


Since: Aug 11, 2004
Posts: 1420



(Msg. 4) Posted: Sun Oct 31, 2004 8:52 pm
Post subject: Re: stumped! will not go through BIOS sequence [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)

Neal McEwen wrote:

 > I have been trying to fix my son's PC. It is like the monitor does not
 > see the computer. When you turn on a computer, it normally goes thru
 > the BIOS sequence and shows you what it is doing on the monitor. This
 > PC does not even do that.
 > The first thing I tried was a new video card -- no luck.
 > Then I tried a new motherboard -- no luck.
 > The BIOS is on the motherboard, so if the mother board and video card
 > are new, what is left?
 > I measured all the voltages on the ATX connector from the power supply
 > while plugged into the motherboard. They all measure about 30% high on
 > a DVM. Is this indicative?

Well, it's indicative that SOMEthing is wrong because 30% is WAY out of spec.

 > We unplugged all the ribbon cables, thinking something else was dragging
 > down the MB -- no luck.
 > I don't think it could be the CPU, because even without a CPU or with a
 > bum CPU should'nt it still go thru the BIOS sequence?

No. There's nothing to 'run' the BIOS without a CPU.

 > I am open for suggestions. Can anyone give me some fresh ideas?
 > Thanks for any help!
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
Dave C.

External


Since: Oct 05, 2004
Posts: 448



(Msg. 5) Posted: Mon Nov 01, 2004 4:38 pm
Post subject: Re: stumped! will not go through BIOS sequence [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)

"Neal McEwen" <nmcewen.TakeThisOut@sbcglobal.net> wrote in message
news:P_dhd.9092$bP2.7223@newssvr12.news.prodigy.com...
 >I have been trying to fix my son's PC. It is like the monitor does not see
 >the computer. When you turn on a computer, it normally goes thru the BIOS
 >sequence and shows you what it is doing on the monitor. This PC does not
 >even do that.
 > The first thing I tried was a new video card -- no luck.
 > Then I tried a new motherboard -- no luck.
 > The BIOS is on the motherboard, so if the mother board and video card are
 > new, what is left?
 > I measured all the voltages on the ATX connector from the power supply
 > while plugged into the motherboard. They all measure about 30% high on a
 > DVM. Is this indicative?
 > We unplugged all the ribbon cables, thinking something else was dragging
 > down the MB -- no luck.
 > I don't think it could be the CPU, because even without a CPU or with a
 > bum CPU should'nt it still go thru the BIOS sequence?
 > I am open for suggestions. Can anyone give me some fresh ideas?
 > Thanks for any help!
 >

Do you know that your DVM is OK? To me, your post points to several
symptoms. 30% is way too high for voltage readings. BUT, if your power
supply was bad, it is somewhat unlikely that it would be bad in a way that
your DC voltages would all be about 30% too high. That's why I'm wondering
about the accuracy of your DVM. If your output voltages really ARE 30% too
high, then your CPU is not reading "good" voltage, and thus it will not run
POST. So the simple fix would be to replace the power supply, and hope that
those sky-high voltages did not damage anything else.

For future reference, your computer does (roughly) the following when you
turn it on.
- First, the CPU is looking for a good power signal. Thus, your power
supply has to be OK.
- When CPU sees power good, it starts running POST program stored in BIOS.
(thus your power supply and CPU need to be OK)
- During POST, the video card might eventually be initialized, if the
hardware passes certain very basic checks first.
- If the video card can be initialized, then you will get video on your
monitor, showing RAM being tested and other components being initialized.
- Final step is for the CPU to look for an OS to boot, according to the
boot sequence that is stored in CMOS.

Of those five steps, you have a system that is stuck somewhere in step one
or two. I suspect a bad power supply. But even if I'm right on that, a bad
power supply can lead to other problems. A bad motherboard or bad CPU could
stop the process in step one or two, also. As you've already tried a new
motherboard, you are probably looking at a bad power supply or bad CPU, with
power supply as most likely suspect. -Dave<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
nmcewen

External


Since: Oct 31, 2004
Posts: 2



(Msg. 6) Posted: Tue Nov 02, 2004 12:51 am
Post subject: Re: stumped! will not go through BIOS sequence [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)

OK, thanks much for all the help from each of you that responded.
to answer the questions.
1. I see the leds light up on the keyboard for an instant, so something
is talking to the keyboard.
2. There is no beep from the speaker and I have it hooked up.
3. I just put the DVM accross a new duracell AA and it read 1.60 volts
-- looks like the DVM is that that far off.
If all the voltage read 30% high will the CPU/MB shut down or has
the PS fried both of them?
I have an old case from a Pentium I machine -- I'll look at the PS
to see if the pins and voltages are the same.
Once again, thanks for the help.

Dave C. wrote:
 > "Neal McEwen" <nmcewen RemoveThis @sbcglobal.net> wrote in message
 > news:P_dhd.9092$bP2.7223@newssvr12.news.prodigy.com...
 >
  >>I have been trying to fix my son's PC. It is like the monitor does not see
  >>the computer. When you turn on a computer, it normally goes thru the BIOS
  >>sequence and shows you what it is doing on the monitor. This PC does not
  >>even do that.
  >>The first thing I tried was a new video card -- no luck.
  >>Then I tried a new motherboard -- no luck.
  >>The BIOS is on the motherboard, so if the mother board and video card are
  >>new, what is left?
  >>I measured all the voltages on the ATX connector from the power supply
  >>while plugged into the motherboard. They all measure about 30% high on a
  >>DVM. Is this indicative?
  >>We unplugged all the ribbon cables, thinking something else was dragging
  >>down the MB -- no luck.
  >>I don't think it could be the CPU, because even without a CPU or with a
  >>bum CPU should'nt it still go thru the BIOS sequence?
  >>I am open for suggestions. Can anyone give me some fresh ideas?
  >>Thanks for any help!
  >>
 >
 >
 > Do you know that your DVM is OK? To me, your post points to several
 > symptoms. 30% is way too high for voltage readings. BUT, if your power
 > supply was bad, it is somewhat unlikely that it would be bad in a way that
 > your DC voltages would all be about 30% too high. That's why I'm wondering
 > about the accuracy of your DVM. If your output voltages really ARE 30% too
 > high, then your CPU is not reading "good" voltage, and thus it will not run
 > POST. So the simple fix would be to replace the power supply, and hope that
 > those sky-high voltages did not damage anything else.
 >
 > For future reference, your computer does (roughly) the following when you
 > turn it on.
 > - First, the CPU is looking for a good power signal. Thus, your power
 > supply has to be OK.
 > - When CPU sees power good, it starts running POST program stored in BIOS.
 > (thus your power supply and CPU need to be OK)
 > - During POST, the video card might eventually be initialized, if the
 > hardware passes certain very basic checks first.
 > - If the video card can be initialized, then you will get video on your
 > monitor, showing RAM being tested and other components being initialized.
 > - Final step is for the CPU to look for an OS to boot, according to the
 > boot sequence that is stored in CMOS.
 >
 > Of those five steps, you have a system that is stuck somewhere in step one
 > or two. I suspect a bad power supply. But even if I'm right on that, a bad
 > power supply can lead to other problems. A bad motherboard or bad CPU could
 > stop the process in step one or two, also. As you've already tried a new
 > motherboard, you are probably looking at a bad power supply or bad CPU, with
 > power supply as most likely suspect. -Dave
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
Dave C.

External


Since: Oct 05, 2004
Posts: 448



(Msg. 7) Posted: Tue Nov 02, 2004 12:51 am
Post subject: Re: stumped! will not go through BIOS sequence [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)

"Neal McEwen" <nmcewen.DeleteThis@sbcglobal.net> wrote in message
news:GZzhd.14684$Al3.9718@newssvr30.news.prodigy.com...
 > OK, thanks much for all the help from each of you that responded.
 > to answer the questions.
 > 1. I see the leds light up on the keyboard for an instant, so something
 > is talking to the keyboard.
 > 2. There is no beep from the speaker and I have it hooked up.
 > 3. I just put the DVM accross a new duracell AA and it read 1.60 volts --
 > looks like the DVM is that that far off.
 > If all the voltage read 30% high will the CPU/MB shut down or has the
 > PS fried both of them?
 > I have an old case from a Pentium I machine -- I'll look at the PS to
 > see if the pins and voltages are the same.
 > Once again, thanks for the help.
 >

Actually, a new AA should read about 1.6 volts. So it looks like your power
supply is WAY off. Voltage that high could damage a CPU or certain
motherboard components, but hopefully that hasn't happened. First thing to
do is replace the power supply. If that doesn't help, maybe the CPU is bad.
But if the power supply is really 30% high (seems that way), then you know
for certain that the power supply is definitely bad. Start with what you
know, and work from there. Replace the power supply. -Dave<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: stumped! will not go through BIOS sequence 
Back to top
Login to vote
Display posts from previous:   
Related Topics:
PC NO POST -- I'm stumped on this one )o: - Ok lads and lass's, Here's the problem. my wifes PC WAS working absolutely fine most of the time but more and more often it started to switch off with NO warning at all. It then would'nt even POST when I attempted to restart. No bios screen no hard..

OK, I'm stumped . . . need portable speaker recommendation.. - Got roped into building a SFF (small form factor) system for a friend who needs a portable system. Portable, meaning, will never run off batteries, but will be moved every few months, and can be checked onto an airplane easily. Needs to fit into two..

BIOS Problem - I just built a system using a GA-8IPE1000 MoBo, and I can't get into the BIOS setup. System components are: 2 sticks of Crucial PC-3200 256MB 400 DDR-SDRAM, total 512MB, and an Intel P4 2.8GHz proc running on a 533MHz BUS, video is a BFG Asylum GeForce4...

Dual BIOS - What are the advantages and disadvantages of it? And what would be the reason for it? Thanks ahead of time

Bad HD, not seen in Bios? OPTIONS??? - I have a Maxtor HD under warranty but will lose the data. The best price I got so far started at $400 for data recovery, YIKES! Anyway, it won't power up, would use the maxtor diagnostics but as I said since it doesn't power up it is NOT seen in the..
   Hardware Problem Solving Community! (Home) -> Home Built All times are: Pacific Time (US & Canada) (change)
Page 1 of 1

 
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



[ Contact us | Terms of Service/Privacy Policy ]