No Video, No Beeps

[Raphael Argus]

Hello All, having some trouble and I know it's something I'm doing wrong but I just can't figure it out.

I'm setting up a PC, I can't get a Beep or any video. I have a 500 Watt PSU, all fans and hard disk power up. I know I'm doing something incorrectly because I'm getting this on two different motherboards that both worked fine a week ago, and using two different processors and trying 3 different vide cards. I've taken the PSU out of my case and set the MB on an anti-static pad and am trying to fire this thing up with only HDD, Video and Ram. What the heck could I be doing wrong???? With both boards I get what looks like a good power up and no video signal. I'm stumped. I read the suggestions on this site but I must be overlooking something. I also tried using three different monitors. The PSU is fine, it's powering my PC currently... I had this system running fine and then I had to go take it apart. It's my wifes computer and I think she's pretty irritated lol

 

[zerozero]

From your post I take it you can't enter BIOS at all but if you can, try and reset it to default values...If what I suggest doesn't solve your problem, please post some specs such as MOBO brand, OS etc...
Since it is not in your post, I'll mention it, you also need a keyboard plugged in and your CPU.
If you are not entirely sure of what you are doing, I would suggest NOT to fire it up on an antistatic bag. Some of these bags conduct electricity and that is how they get rid of ESD so your MOBO might be grounded if sitting right on it. Assemble what you can with your MOBO sitting on it (CPU, HS and fan, memory) and then put it back in the case. Check all connections and make sure that everything is well seated. If your MOBO is for a P4, there is a second square connector for a 12 V (square plug with 4 pins) which is required and was not supported by older PSU. Check your light cables (HDD etc...)and make sure they are not reverse. Your MOBO manual will tell you where to plug them. If the configuration changed, i.e. the HDD is being installed on a different MOBO, you'll need to repair your OS as it is looking for the MOBO to which it was installed first.
I would start with this. If it doesn't work, post back again and we'll take it up from there.

 

[Raphael Argus]

Thanks for your post. This is an old PC, a PIII600 Tyan S1854. It's my wifes machine, I upgraded my PC and tried to pop in my old Abit MOBO but after installing everything I learned the old PSU did NOT have the needed 4-pin connector you mentioned above.

Basically I am putting the same MOBO + CPU back into the box it was just removed from two days ago. (working well) I'll try again.

I did NOT have the reset, power LED and HDD led plugged in. Does that make a difference? I purchased this box second hand and do not have the manual. I downloaded a .pdf manual but it does not show a picture of the motherboard with descriptions of where to plug the LED lights etc. I did find the 'power on' pins. I get power, all fans operate. If I connect CDROM or Floppy all lights just remain on. I'm feeling like a complete idiot here. I put my new MOBO + CPU in without a hitch, just told the new bios to boot to CDROM and did a fresh XP install. Any ideas would be appreciated.

And this PC Case stinks! It doesn't even have motherboard screws. It has some crummy hooks that stick out.

 

[Nubius]

Sounds like the common case of a dud CPU. Same thing happened to me because the guy at the CPU store put thermal compound on a thermal pad and it spread on the connectors near the core and caused instability.. It does the same thing, fans on, powers up basically, but no video signal, no beep, no nothing....dead CPU..I was able to clean off the goop and it worked again, but if you've been reseating it chances are its the CPU you're trying itself.

 

[Raphael Argus]

The mobo and CPU worked great two days ago. I'm just putting something back together incorrectly, I know it. The CPU was never removed from the Mobo.