found this gateway gt4010 computer curbside, no hard drive but still has memory sticks & dvd. stuck in a bootable hard drive and plugged in a monitor & mouse & keyboard. power supply apparently good, hard drive powers up, cpu fan powers up but no light on front. however NO BEEPS and no display on monitor.
i suspect a bad MB now. or maybe a bad cpu?
reseated all connectors, cmos battery still good, reset cmos. the MB is apparently
2006 mfg (FIC KTBC51G Motherboard), still NO BEEPS.
IF i could get a bios flash disk, doesn't the MB and cpu have to be working to flash bios?
I agree with James.. Try a different power supply. The first step I usually take when a PC is not giving any signs of life is to remove everything from the motherboard except the CPU.. It should give you some beep codes with nothing but a CPU on the board. Then start putting cards and memory back in one at a time to see what is causing your issues.
: > i suspect a bad MB now. or maybe a bad cpu? : >
: > reseated all connectors, cmos battery still good, reset cmos. the MB : > is apparently : > 2006 mfg (FIC KTBC51G Motherboard), still NO BEEPS. : >
: > IF i could get a bios flash disk, doesn't the MB and cpu have to be : > working to flash : > bios? : >
: : I agree with James.. Try a different power supply. The first step I usually : take when a PC is not giving any signs of life is to remove everything from : the motherboard except the CPU.. It should give you some beep codes with : nothing but a CPU on the board. Then start putting cards and memory back in : one at a time to see what is causing your issues. : : Mike
Providing it has a speaker attached and attached in the right place.
thanks for the input guys. removed the only pci card (a soft modem), there was no video card in the video slot but the MB has a VGA connector on the rear of the MB, there are no signs of pins shorting in the video slot, i unplugged both IDE cables, there is no cable in the floppy connector.
tried a known-good power supply, same identical results, NO BEEPS, just the cpu fan blows. the on/off button on the front works but there is no on/off light.
i guess this points to a failed MB. don't MBs fail more often than cpu's?
After all that, you still don't know even if the power supply 'system' is working. What is and is not working? If you cannot answer that question, then accomplished is nothing. Even a new and working power supply can appear defective in another system - and you still have no idea what is and is not wrong. Reason for responses that are 'try this and try that' are due to no numbers. Insufficient information means those who could really answer your questions will remain mute.
In two minutes, with that 3.5 digit multimeter, numbers will elicit a response that says what is *definitively good* or *definitively bad*. Procedure is in "When your computer dies without warning....." starting 6 Feb 2007 in the newsgroup alt.windows-xp at:
Important are those numbers both before and when power switch is pressed. Post them here. Don't remove or change anything to get those numbers. You don't need an o-scope. Don't bother with core and memory voltages. Just get those numbers in that procedure. First establish facts - what is *definitively good*.
A meter is sufficient. For starters, I can think of four voltages to check: CPU Core (1.3-1.4V) DDR Core (2.5V) DDR Termination (1.25V) Chipset Core (could be 1.2, 1.5, 2.5 or other voltage)
Three of these supplies are located below the CPU socket; from the left, there are groups of 4, 3, and 3 output caps. Measure the voltages at one cap in each group, or the cap side of each inductor. The fourth supply appears to be to the left of the IDE connectors, with the caps below. If any of these voltages are zero (or less than a volt), check for a blown FET.
your input is greatly appreciated. there is an oddity, am not sure of its significance, but when i plug the 110v power cord into the back of the PS, the computer thinks it is already "on" and powers up the cpu fan. under this condition (and with no ide or floppy cables and no pci cards plugged in), from backprobing the MB power connector, the voltages are:
It is called a power supply 'system'. Power supply is only one component of the 'system'.
Does not matter how many supplies are swapped. Every component is still "unknown". After all that shotgunning, every component remains unknown. We need components to be either "definitively good" or "definitively bad". All that swapping still means nothing is "definitive". Therefore nothing is accomplished.
Not only does a meter define things "definitive". The meter also means others with knowledge then will reply with real world facts. No useless "it could be this or could be that" posts. Only two minutes with a meter would have made redundant most of the last ten posts.
The procedure discusses only in wire colors because those pin numbers can be confusing - counted 1 to 2 across the connector, or 1 to 10 down connector length.
OK, red wire is what? : 4.988. Purple is 5.013. Orange is 3.35. Yellow is 12.15. Green is well above 2 volts when powered off and well below 0.8 when switch is pressed. Power supply controller telling power supply to power on. Why does purple wire show 5.012 when computer is not powered? Power supply controller needs 5 volts to monitor the power switch.
That purple wire is also why nothing can be installed or removed without power cord removed from the wall. Some circuits are always powered even when computer appears off. Parts inside a PC are not designed to be 'hot swapped'. Hot swapping can damage parts.
Gray wire went from zero volts (not listed) to 4.708 which means power supply told power supply controller that PSU was OK.
BTW, I believe you have numbers wrong. Pin 16 should be 14. What is listed as pin 13 should be pin 11. Examples of why we use wire colors instead of pin numbers.
Not only are these voltages good. Numbers are also healthy; well within expected values. The power supply 'system' is clearly OK. Move on to other suspects without even looking back.
Confirm motherboard battery is OK using the meter. Don't remove the battery. If it is a CR2028 coin cell, then that 3 volts battery is completely OK if above 2.8 volts (while in socket). If less than 2.9 volts, consider a battery replacement in the next six months if computer does work. Again, no wasted money swapping batteries. Battery and its connected circuits verified in less than 20 seconds using the meter.
Next, strip the computer down to nothing but CPU, motherboard, power supply, and speaker. No keyboard, memory, mouse, video card, disk drives, etc. Nothing but those four items. If those three items work, then speaker will beep. If not, then you know which of three items has failed.
Visual inspection might find the rare problem - a metal fragment underneath a chip, a swollen capacitor, a short to chassis standoff, etc. I have used an o'scope to repair a motherboard by finding a cracked trace underneath a peripheral card connector. But that takes experience, equipment, and time that you don't have. If the 'four item' test fails, then you know maybe CPU but most likely motherboard is defective. Numbers say the power supply 'system' was not causing other parts to appear defective.
You could measure CPU voltages as tonym suggested. A failed voltage could mean a defective FET (which you will find difficult to locate). But it could also identify a defective electrolytic capacitor which is maybe $1.50 and easy to obtain. Then you have fixed the motherboard. However my experience is that failures in this region tend to involve parts that are not obtainable. Cannot hurt to take one minute to look at those voltages - if the four item test fails.
Swapping out a power supply did not provide useful facts. We can say "definitively" that all parts of the power supply 'system' are functioning. Failure is something else by taking only two minutes with the meter.
Try removing the CMOS battery for a day or two. I've had boards that were dead, even after clearing the CMOS, but they worked after removing the battery for a long time.
CPUs almost never fail. The only bad ones I've seen were caused by overheating (running with no heat sink), or over voltage from a bad motherboard. Only older AMD CPUs are easy to blow from lack of cooling. Most other CPUs simply lock up if they get too hot. I've never seen a bad Intel CPU.
If the CPU is getting warm, then it's getting power (although not necessarily the correct voltages).
Are there any bulging caps on the motherboard, or in the power supply? A bad power supply can damage the motherboard, so don't use a valuable system to test it. Andy Cuffe