New computer problems

[Jimshady]

Hey guys,

I just put a new PC together:
Asus P5LD2 mobo
Pentium D 820
Something X300
Thermaltake xp550 np psu

I had to get a 20-24 pin adapter for the psu.

Basically, I press the power button, and the chassis fans spin maybe one step, but there is nothing after that. If I press the button after that, there is no spin. I must unplug the psu, and plug it in. Then I get another spin, wooo.

If I remove the 4-pin psu-to-mobo power lead, all fans power up, and the hdd spins up. But no display, no beeps, no voice diagnosis. I know this needs to be plugged in, I just thought it was curious.

I have pretty much ruled out video card.

This is all new hardware, and it is hard for me to find components to test with. Can anyone have a stab at what could be going on? Is it a grounding issue?

..Regards..

 

[Tannin]

I'll take even money it's the power supply. All the symptoms fit. But then I wouldn't rush out to say the PSU is an actual dud; quite a few recent boards are pretty fussy about power supplies, and if there is a firm that positively defines the term "fussy bitch of a main board" it is ASUS. But you are sort of stuck with the ASUS now, so try it with a different power supply (a good one, and one that has all the latest connectors already fitted).

Oh, and the other thing you always do under these circumstances is pull the board out of the case and test it stark naked on the bench. Have the board naked, I mean, not yourself - i.e., with everything disconnected except for the bare essentials: minimum possible RAM, a reasonably modern, known working, but not too fancy video card that doesn't suck too much juice (a Gforce 4MX or something similar) and nothing else. You don't need a keyboard or a mouse at this stage, and you can use a screwdriver to short the power-on pins, so you don't need any cables either.

Do this first.

No, do it second. First, while it's still in the case, double check that you have disconnected all the IDE devices and pulled out any expansion cards. Then test it naked on the bench. After that, swap the power supply. Swap the RAM too, if you have some spare stuff.

 

[Bozo]

This might sound strange, but pull the motherboard battery for a few minutes. Let the BIOS get real stupid.
Then try to power up.

Bozo :mrgrn:

 

[time]

Try it without the 20-24 pin adaptor. The extra pins aren't essential, and it sounds like it may be wired incorrectly.

 

[Jimshady]

Time: Thanks mate. I did originally try without the adapter, mainly because I didn't even realise the difference when I bough the gear. Nothing different happens.

Bozo: Yeah I tried it, made it hella-stupid, still no luck :/

Tannin: I'm guessing you're on the money. I'm going to buy a new PSU at lunch time today. I've tried transplanting it all out onto a table, no luck. Thanks for the input.

...wonder if it was that Corsair Value RAM that a went cheap on.

 

[Jimshady]

Uhhh... yeah, replaced PSU. Same story. Guess it's new mobo time... right guys?

 

[time]

Well, yeah. The power supply was by far the most likely candidate, the next is the motherboard.

I had something similar where it turned out the PS just wasn't compatible/capable with a particular motherboard, but as long as you tried a different model PS, that scenario doesn't seem to fit.

If the 4-pin connector is feeding the CPU voltage regulators, maybe the symptoms indicate they're history?

 

[time]

Or, it might mean the CPU is history.

 

[time]

Speaking of which, have you tried reseating the CPU? It is socket 775, after all. :-? No bent pins?

 

[Jimshady]

Well I really havn't taken a look at the CPU. Everything seemed to slip into place perfectly. What would you expect to happen if the CPU wasn't in as expected? No fans / anything happening?

 

[P5-133XL]

If the CPU is dead then nothing happens (including beep codes and any form of fan Movement). The CPU runs the bios ROM to self boot and a dead CPU means no code gets run and nothing happens. Now bent/broken pins may mean anything from does not matter and cpu runs fine thru to totally dead with some peculiar intermediate states like runs but locks-up frequently. Most of the time it will be in the dead or runs fine state with the much more emphisis on dead. It all depends on what pins are not connected...