hard drive light on, spins up, no signal to monitor or keyboard

[nlm9802]

and hard drive doesnt do anything after spinning up.

all cables are correctly installed, hdd is on master setting, also tried cable select, still nothing.

the video card is agp and in the slot, keyboard is plugged in keyboard port etc etc.

it's really odd, never seen this problem before. I'm about to try swapping out hard drives/ide cables and see if that works.

anyone else had a similar problem? no beeps from post, just whirrrrrr, then the normal accessing sound it makes, then nothing.

 

[BFOJ]

Sounds like a memory problem. Have you replaced or added memory recently?

 

[nlm9802]

have not, but I will try changing that out with some known good ram also.

 

[BlueAlloy]

Was this system working before, if so what have you changed? New HD? If your not getting any signal to your monitor you may have a video card issue, perhaps reseating and checking cables.

 

[stuartd]

Is this a new build, upgrade, or a previously working and un-touched machine?

Disconnect all devices apart from video card/ keyboard - do you get anything now?

 

[edfair]

Should get keyboard flash on power up initialization regardless of memory problems. Sounds more like a power problem. Ed Fair
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[nlm9802]

indeed, after further research and replacements the problem appears to be the power supply.
I just temporarily used a working computer of the same model/configuration and swapped the hard drives.

 

[SDMguru]

If you swaped the hard drive from the broke PC to another PC and it works, all that tells you is that the hard drive works. It doesn't say anything about the power supply.

If your PS turns on and supply's power to your hard disk and makes the lights come on it's probably not PS.

If you get no video and no beep code it means your CPU is not working properly (CPU is needed for motherboard to run diagnostics) or it is beeping and the speaker isn't plugged in for you to hear it.



Things to try

1.) Check speaker connection (if speaker is on board skip to step 2).

2.) re-seat your CPU and check that the motherboard is configured correctly for that CPU. IE 100vs133 FSB etc.

3.) If it doesn't power up or get beep code after that then remove everything from the motherboard except power, the case LED's/Power switch/speaker, and the CPU. IF you still don't get a beep code it's definately a bad component. Either CPU, PSU, or Motherboard.

 

[SDMguru]

Just to re-itterate memory problems will always beep code. CPU problems never will.

 

[attrofy]

I had an identical problem with a sstem - everything powers up, but nothing comes on - just a blank screen, and lots of fan noise.

Come to find out, it was the motherboard (or a mounting screw) grounding on the case. A swift "bonk" or firm squeeze on the side of the case (Motherboard bottom side) and the problem was resolved. This happend quite often anytime I had to move the case to reposotion the PC, or for minor upgrades to get to the internal components.

 

[edfair]

attrofy,
you were lucky. What eventually happens is the screw grounds out something critical and blows the M/B.

nlm9802,
This problem has reached the point that test tools would be nice. A voltmeter for the PS, and a logic probe for seeing if the CPU is clocking.
ATX has dual voltages for the M/B. The low voltage can die without affecting the other voltages. But the CPU won't clock. You have a duplicate PS. That would be fairly easy to swap.
SMDguru's last paragraph is the next step but I would probably try it with the M/B floating on cardboard to eliminate any ground possibility. Ed Fair
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[attrofy]

Ed,
Actually, that was my ultimate goal, as the thing needed to be replaced from the get go - sadly, it is still running strong....

 

[nlm9802]

i tried removing the ram and it did beep, still no video though.

I am about 99% sure one of the voltages died in the PS.
the only things that i can see getting power are: the cpu fan, the ide drives (hdd, cd, cdrw), the lights on the front of the case, the onboard nic, and the pc speaker.
no power for the keyboard, vieo card, and probably mouse. probably more too, but thats all i know for sure.

 

[edfair]

Keyboard should be the same PS as the front lights. Unless it is fused, and blew.
I have a little test block with DIN5s one male , one female and a test block in the middle that I can plug between the computer and keyboard to monitor the voltage and signals for these type of problems for the keyboard. Otherwise it is a pain to troubleshoot. Ed Fair
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[SDMguru]

Try re-seating your ram one more time then (and for troubleshooting do it with one stick in a different slot each time. It'll take you maybe 5 minutes to try.


The reason I don't think it's your power supply is that your hard disks use both 12v and 5v taps and they spin up fine. Also your CPU and memory use the other 3.3v and 2.5v taps and if those were out you would not get beepcode or be able to turn your system on. It's simple enough to check though. If you really want to check PSU And you don't have a spare to try then measure the voltages at the pins with a voltmeter. You can find the pinout on the web or often on the PSU.

The fact that it beeps without ram but not with makes it look like possible ram issue. Also pull out everything in the way of cards (even video) and see if you get the same ora a different beep code.

 

[BFOJ]

Power Supplies have a "power good" signal, if any voltages fall outside the normal range (i.e., short, low voltage), the power supply will provide no voltages. Might pay to have a voltmeter on hand for future use.

 

[edfair]

Most continue to provide the voltages, just kill the oscillator so no CPU clocking. But the beep indicates clock is running.

nlm,
when you put the memory in, rock it from rest to almost latch 5 or 6 times before latching it to possibly break through any oxidation on the contacts. Unless it is SD , then replug it several times. Ed Fair
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.