CD and fans light up, but no post

I have a hardware question and was hoping maybe someone here could help me troubleshoot.

I just replaced my 1.2 T-bird CPU with an XP 2400+ (coudn’t find a 2600+). I am not sure if it’s related, but twice now since I made the switch, I’ll start up my computer and the CD lights up, fans start going, but the monitor never wakes up and I never get to post. If I cycle the power, the next time it starts up just fine.

I wonder if it’s a weak power supply? I’m pretty sure my current one is 300w, so I wonder how much power I must need. AMD recommends 300W, but says that it can vary depending on what you have installed. I have a CD burner, DVD drive, 2 disks, GF4, Audigy, NIC, controller card, and like 4 case fans.

I have no idea how to determine a systems actual power needs beyond just figuring, “That oughta work.” What do you guys think? Power supply? Something else?

Well…that’s probably not enough power for what you have in there regardless of whether it’s causing the problem or not.

That’s definitely not enough power for what you have in it right now. But whether it’s causing the problem or not, since it’s seemingly random, is hard to determine.

Ok, so how do I determine how much power I need from my power supply, so I can upgrade?

Hey Tim…

I just put my new system together the other day and I my setup consists of:

DVD drive
CDRW drive
AMD XP 2000
Gigabyte mobo
Geforce 4 4200 (128 mb)
100 gig hd
40 gig hd
Audigy Sound Card

And too power all of this I got the Enermax 420 watt p.s.

You might want to do the same to play it safe. I got the power supply at: FrozenCPU Home Page

It’s only $100.00 and you shouldn’t have any power related problems.

Also… check out that see through Enermax p.s.

:D has a recent article on what size power supply you need for your rig. Read the article and go pick up an appropriately sized Antec power supply at compusa and you should be good to go.


To test it - strip everything off the MB but the video card, cpu and ram - and of course the powe connection. To be sure, take the MB out of the case and place it on cardboard or something similar. I have had a case touch a MB and short the system before.

Hit the power on, you should get the beep and a screen at that point. If not, remove the ram. If you still don’t, something is really really wrong.


Thanks guys. Looks like I should break open the box and see how much voltage each of my components actually needs, then shop for a p/s that can meet the demand. That firing squad article was pretty informative. Thanks for the link David!

I had this very same problem with a new gigabyte mobo, and I don’t think it’s power-supply related because after it boots it runs fine and I have a new power supply with plenty of juice. For some reason I had to cycle the rear power switch before it would reboot after shutdown. A restart was fine, but if I shut it down overnight in the morning it wouldn’t boot without cycling power.

A friend told me it was probably an XP conflict. In the BIOS make sure you change the state from S1 to S3 and turn off any power management control panel options–so Windows isn’t trying to control when your computer boots or shuts down. I also found using “stand by” instead of “shut down” cured the problem.


Hi Ian,

Thanks for the suggestions. When your friend says an XP conflict, is he refering to the OS or the actual chip? Conflicting with what, may I ask?

And what do the BIOS options for S1 and S3 states control? I have been through the BIOS, but I don’t think I’ve run across anything with these names.

Also, if you use “Stand By” instead of “Shut Down,” isn’t this like asking Windows to control when your computer boots and shuts down?

It sounds like it could very well be a power issue. I’d try and grab a 400 or 450W PS. I got a case + 450W power supply through pricewatch for about twenty bucks, plus another twenty or so shipping. It’s a great case, too. So, a new power supply shouldn’t be too expensive.

Probably the power supply. I had the same thing start to happen with my old Athlon XP system when the PS started to crap out – I’d have to turn it on three or four times before it would “take.”

Don’t take Murph’s advice on the power supply, though. You get what you pay for on a $20 power supply. If you problem is that you’re not getting enough amperage on a certain power rail, just going for a “400W” or “450W” isn’t necessarily going to fix things. I’ve seen generic 450W power supplies that supply only 2/3 the amps on the 12V line as a name-brand 350W supply.

Generic supplies may work for some systems, but given that you’re having problems now, I’d suggest investing in an Enermax. (Second choice would be Antec.)

Thanks guys. I am still thinking it is the power supply, too, but wanted to cover all my bases. I have to work this weekend and next week, so the soonest I can do a full scale investigation is probably going to be the weekend after next. :roll: Interestingly the current p/s is the one that came with my Antec case, and I’m pretty sure it’s a 300w.

I really do want to look at the power ratings for all my parts and see what I should buy. I think it was Supertanker that just posted (in another thread) that he ended up going with a 350w Enermax, which had more voltage on the 12v rail than some 400w p/s. Nothing worse than buying a part that doesn’t solve your problem.

Tim, FWIW, the power supply I had this problem with was… a 300W Antec case power supply.

The 430W Enermax solved the problem nicely.

Interestingly, that same Athlon motherboard is now in a case with an old 275W PC Power and Cooling “silent” supply, and works fine there too. So it was something wonky with the Antec.

(Apparently Antec’s stand-alone supplies are better-built than their case bundle supplies, but I’d go Enermax just to be safe.)

Huh. Thanks for posting Denny. I was puzzled because Antec is a name brand and I guess I expected more headroom in the full tower case I purchased from them.

Along with my power problem, I seem to be having another, seperate issue. The latest bios for my ECS K7S5A motherboard has a problem with “remembering” the CMOS settings. Occasionally I need to go in and set all the settings over again or I end up with an underclocked CPU, running at 100mhz. Oiy. It doesn’t take long to fix, but it’s pretty annoying.

Maybe I will just get me one of those Nforce2 motherboards everyone was talking about not too long ago. Lucky for me I didn’t purchase DDR RAM yet, so I can still get some of the fast stuff.

That was me. I checked power supplies at Best Buy since I had a gift certificate, and the Antec 350w put out 16 amps on the 12v rail. Since my calculations showed I needed almost 16, I was reluctant to buy that. Best Buy also had a 450w Antec, but it still only made about 20 or 22 amps on that rail, and was $100. When I checked the Enermax 350w (about the same price at PC Club as Best Buy had on the Antec 350), it buried the Antec, putting out 26 amps on the 12v rail and 32 amps each on the 3.3 and 5v rails. Plus it has two fans and can be monitored if you have the right plug on your motherboard. And a p1mp gold fan grill on the back. I’m in love with Enermax now. I want to have, like, 10,000 of its babies.

Ditto what Supertanker said about the Enermax. One of those “wow, they make these well” products. The dual fans brought my case temp down by a degree or two C, and the model I got has an adjustable speed rear-fan that you can turn down to lower the noise.

I don’t know. I’m pretty sure it’s not a power supply problem with mine, but something to do with the Gigabyte motherboard. I changed the ACPI suspend type in the BIOS from S1(POS) to S3(STR) and this seems to have fixed the problem–but it doesn’t look like you have that option. I don’t think changing the Windows XP power options does anything. but it was something that my friend recommended.

I did a bit of searching and found this thread about your board:

A couple people there seem to agree that it’s not the power, but the CMOS that’s the problem. They recommend removing the battery from the motherboard and letting all the power out of the system, then replacing the battery and rebooting. Anyways, hope you find a solution.


Okay, don’t take my advice, apparently – but what I’ve got runs everything I need it to run, and the case is downright sexy. :-)