Instructables

Whenever I try to turn my computer on, it takes many attempts. Anyone know whats wrong?

My computer is an HP Media Center PC m7640n, that is not modded in any way, running Windows XP Media Center Edition. I have had it for almost two years now. One day, I went to turn my computer on, but found that it would not boot. The screen was blank, the hard disk read\write light is off, and my internally mounded SD readers light was solidly on, which would normally mean that it is reading an SD card. (note that my CD tray could still be opened.) So then I held in the power button till the pc turned off, then turned it on again. The same thing happened. So then I unplugged it from the wall, let it completely cool down, then started it again. Everything was the same like last time, but all the fans were blowing full power! It kinda sounded like a dustbuster (portable vacuum). So after many tries (5-30), my computer will finally start up. It works completely perfectly while it's running. But, if I turn my computer off, the same thing happens. The amount of tries it takes for me to turn my PC on is anywhere from 1 to at most (I've counted) 49. So now I just leave my PC on all the time.

I have tested POST just to make sure that the motherboard is working, by removing both RAM chips and expecting beeps when the computer is turned on. I did hear a series of beeps, which means that my motherboard is OK. I have also tried turning my computer on with no accessories (mouse, keyboard, WiFi, mic, sound, Bluetooth, even the monitor. But still, no effect. I even replaced the power box, still no effect...

I have included pictures of different things I described above, and pictures of the motherboard and the label on the power box. I am almost 100% sure that this is a hardware problem. If you need any more technical information, just ask away in the comments! Thanks!

-Shadow Ops

Arbitror (author) 5 years ago
Just a quick update:
I have moved on, I am getting a new computer. (as you can see from my Disasemble a Computer 'ible)!
Laknight1175 years ago
ur just gettin a blank screen not the blue screen of death have u done any work on it lately or it just started, installed any new programs ect?
I worked on an old computer that had similar trouble starting up, and would also cut off now and then when used in a warm room with no air conditioning. Thoroughly cleaning the insides, then removing and reattaching the CPU heat sink seemed to take care of the problem. Do you have a thermometer that can be used to compare the heat sink temperature with the reported chip temperature?
Arbitror (author)  NobodyInParticular5 years ago
I will try that. But where can you find the heat sink temperature? I have searched the BIOS but nothing there.
I meant actually set the thermometer on top of the heat sink of the CPU and compare that temperature to the temperature inside the chip, as measured by its internal sensor. If the chip temperature isn't showing up in the BIOS, you should be able to download a program (Try Sourceforge) to check it for you. Look for fan controllers or overclocking diagnostics.
Arbitror (author)  NobodyInParticular5 years ago
I meant actually set the thermometer on top of the heat sink of the CPU and compare that temperature to the temperature inside the chip, as measured by its internal sensor.
-I know that, it's just that there is no temperature in the BIOS...
CPUz is a good program...also speedfan (i thinkt thats the name) is another fo r setting fan speed and overclocking and such
The temperature is usually under something like "PC health status" in BIOS L
NachoMahma5 years ago
. I suspect four things: pregnant capacitors, bad PSU, bad connection, and/or bad thermal management chip. . Look on the mobo for bulging or leaking capacitors. . Since you have replaced the "power box", I'd move that to the bottom of the list, but it's still a suspect. . Tear the computer down - remove all cards, unplug all connectors. Clean the dust off of everything. Put it back together. This may take care of oxidized/corroded connections. . Since the fans stay on at full power, the thermal management chip may be bad or getting a bad temperature signal from the CPU.
Arbitror (author)  NachoMahma5 years ago
. Look on the mobo for bulging or leaking capacitors. -Done . Since you have replaced the "power box", I'd move that to the bottom of the list, but it's still a suspect. -Probably not... . Tear the computer down - remove all cards, unplug all connectors. Clean the dust off of everything. Put it back together. This may take care of oxidized/corroded connections. -Unplugged everything, vacuumed everything, then reassembled. Still no luck. . Since the fans stay on at full power, the thermal management chip may be bad or getting a bad temperature signal from the CPU. -The weird thing though, is the fans only go crazy once I have unplugged then replugged the PC from the wall, or hit the switch on the "power box". But if I turn the computer off, then on with the button at the front, the fans are quiet, but still same problem.
My dad's computer does the fan thing too. I think it's just normal boot-up procedure, for some machines.
Arbitror (author)  Padlock5 years ago
No, it only started doing that when It wouldn't even boot.
Arbitror (author)  Arbitror5 years ago
P.S. My computer is only 2 years old, so I don't think that there would be any corrosion or burst capacitors...

P.P.S. What is the proper name for the "power box"?
> ...only go crazy once I have unplugged then replugged the PC from the wall, or hit the switch...
. That sounds like the battery on the mobo is weak/dead.
.
. Power supply or PSU
Phil B5 years ago
I believe the problems you describe can be caused by a failing power supply. The power supply can go bad at any time, although most give long service. When a power supply is at fault, the symptoms can vary and are not always associated with the power supply.
Arbitror (author)  Phil B5 years ago
As I said in the question, I already changed the power supply, thinking that it is the problem.
Phil B Arbitror5 years ago
Sorry. I tried to read your submission carefully, but obviously missed that.
frollard5 years ago
the several attempts tells me that it's a bad connection to your boot drive, or a bad connection to a non-boot device, that sporadically gets in the way. Try booting with JUST your boot (C) drive installed (and kb. monitor mouse etc).
Arbitror (author)  frollard5 years ago
I tried that too, no luck. I even unplugged then replugged in every wire and cable.
fwjs285 years ago
i feel your pain my man....i have a computer that just died on me.. :( ....i think (like frollar) that it might be a bad IDE (or sata) connector or connection...unplug the IDE/ SATA cables and reatch them
Arbitror (author)  fwjs285 years ago
Already tried. No hope.
Padlock5 years ago
Most likely it is trying to boot from the SD card. Remove it and try again.
Padlock Padlock5 years ago
Try and get into the BIOS and look at the boot order, it should be your main harddrive (C:\ , usually) first, then its personal preference, although its recommended to be the cd drive, then the next one, etc.
Padlock Padlock5 years ago
Oh... Apparently you have tried it. Try unplugging the Card Reader completely.
Arbitror (author)  Padlock5 years ago
Already did that. I don't think that the problem has anything to do with the SD card reader...