|When you get symptoms like yours before the operating systems loads , or if there is no operating system available to be loaded, e.g. because you have not loaded one on a partition on any hard drive, then your problem must be a hardware problem.|
You inspected the capacitors on your mboard, and saw nothing obvious.
You may need to look again and use good lighting and a magnifying glass or similar.
If ANY electrolytic capacitor does not have a flat top, or if you see any fluid or dried deposits from fluid on the top of or at the base of a capacitor, or any fluid streaks or dried deposits from fllud on the mboard surface that may have orginated elsewhere, you DO have one of more failed capacitors. However, sometimes there is no physical sign one or more is bad - it / they may be open (the same as if they werre not installed at all).
- the mboard has no onboard video; you're using a video card in a slot.
- the PS capacity is 250 watts.
What is the make of the power supply you're using ?
What is the make and model of the video card you're using, or at least, which video chipset does it have on it ?
Does it have a fan on it, and if so, does it spin fine when you boot the computer ?
AGP cards with older video chipsets usually have no power socket, but may have a 4 square pins connector identical to that on a floppy drive - if it has that you must connect a floppy drive molex connection from the power supply to it.
Most modern mboards will shut off (and NOT Restart automatically) if the cpu fan does not spin or if it's spinning too slowly, or if the CPU fan is connected to the wrong fan header on the mboard, a few seconds to a few minutes after you have booted, when no rpm or not enough rpm is detected from the CPU fan header.
Does the CPU fan spin okay when you boot the computer ?
Is it connected to the CPU fan header ?
If your mboard shuts off and DOES Restart automatically, whern there is no operating bsysatem, that can be caused by
- a defective mboard, e,g, that has failing or dead or missing (they blew up) electrolytic capacitors
- a defective or failing power supply - it rarely if ever causes the mboard to shut off and restart
" if there is a tool which detect those diagnostics which are beyond to an eye see.a tool which can reads on a screen to tell you that, a caps, voltage regulator, resistor,or soso and so component is defective and must be replaced.'
Dell™ Dimension™ 8200 (User's Guide)
System Codes and Messages
You can but PCI diagnostic cards that can generate error codes, but they can only tell you what is wrong generally - they can't tell you which componrent is the problem.,
The most likely thing to be be defective or failing is the power supply, and on the mboard, the electrolytic capacitors
Other components on the mboard rarely fail.
There are some older (earlier released) AM2+ mboards that have voltage regulators for the CPU that are indequate and will fail if you install a CPU that is NOT on the supported CPU list for the mboard model that requires the circuits supply more than ~90 watts, but other than that they are one of the least likely components to fail, if if they did fail it's likely your mboard would not boot at all. For those same mboards, circuit traces on the mboard may burnt out when you use such a cpu.
Resistors don't fail unless they didn't have enough wattage capacity in the first place and in that case they would probably have failed not long after you started using the mboard.
- an AC power failure event that produces power spikes or surges or over voltage,
- a failing power supply
can damage the mboard or anything connecfed to it. The computer does not need to be running for the damage to occur - all that's required is that the PS is plugged in and receiving live AC power, but the damage is likely to be worse if it was.
Damage caused by a lightning strike on the AC power grid or anywhere close enough to the location of the computer can damaged the computer or anything connected to it - all that's required is that the PS is plugged in , whether it's receiving AC power or not.
Connecting a known good power supply may not allow your computer to run normally
- if the power supply does not have enough wattage capacity bto support both the system nand the AGP card's video chipset
- if the mboard is damaged
- if there's anything else wrong on a mboard that is not damaged that can cause the mboard to not work normally.
If the AGP card is damaged, e.g. if it has a fan and it's not spinningnor not spinning fast enough, or if it's ever been plugged in or unplugged when the PS had live AC power to it whether the computer was running at the time or not, it could cause your symptoms
If you can,
- try the AGP card with another working computer,
- or try known good AGP card with your computer,
if the PS capacity is enough to support the video chipset's system PS capacity requirements.
It's far easier to replace the mboard rather than replace components on it. Most people don't have the proper equipment to replace components in any case.
- a soldering iron with a tiny chisel or pointed tip, preferably 40 to 60 watts - less or more wattage is likely to be harmful to the mboard,.
- a solder sucker, or braided wire meant for absorbiing solder
- a large needle or a dentist's pick tool with a suitable tip that solder will not adhere to to help you clear holes you can't suck the solder out of easily after trying a time or two.
Plus, you need a source for the component(s). E.g. I know from experience that local places often don't have the capacitors you need, or if they do, they're most often not the type/ quality used on mboards and may not work as well as intended .
You can often find working used mboards that were in brand name systems on the web for a reasonable price, but make sure the ad says the mboard has been tested and/or is known to be working.