new pc built, wont power up

[Laffertytig]

i woner if anyone here can help. ive just assembled a pc from scratch but it wont power up. surely the PSU should at least power up when i switch it on buy no nothing happens. for testing purposes i tried pluggin the old PSU into the wall as well but that doesnt even power on. i wasnt aware that the PSU had to be connected to the pc hardware to work. any ideas?

also when installing the processor it said to apply thermal grease but i dont have any, is this a problem?

i assume it wouldnt have anything to do with the LED leads as the case i have which has the LED wired differs from the motherboard manual?

windows xp
DABSVAL, 550 PSU -

creative Inspire T7900 7.1 Speakers OEM
CRUCIAL 4GB 240dimm ddr2 SDRAM
SUMSUNG 320GB 7200RPM S300 8MB harddrive
GeForce 8800GTS 320MB PCIE XT
intel Core2Duo E6750 S775 2.66ghz4mb
gigabyte S775 Intel P35 Express ATX motherboard -

there's a cdin socket on the MB Which i could swear has something in it on my old asrock MB, should there somethin in there?
also, there's an 6 pin lead which comes out of the PSU but the only place i can see where it fits is the graphics card, is this correct?

heres are the links

motherboard - http://www.dabs.com/productview.aspx...143,4294953919

PSU - http://www.dabs.com/productview.aspx...ey=11259,50010

harddrive - http://www.dabs.com/productview.aspx...50429,40970000

memory - http://www.dabs.com/ProductView.aspx?Quicklinx=3R5L

processor - http://www.dabs.com/productview.aspx...ationKey=11147

graphics card- http://www.dabs.com/ProductView.aspx...4406&InMerch=1

[Letum]

Have you checked you have the power leads from the MB to the power switch correct?

make sure the correct colour of wire is going to the switch, check the switch is working.

Do you have a electric "multi-meter" ?

IIRC graphics cards usualy have a 4-pin connecter to the PSU.
Don't worry about the CD-in on the MB.

[danlisa]

Thermal Paste is a must.

Do not start your PC without having applied it you will cause severe/permanent damage to the CPU.

[Laffertytig]

no i done even know what a mulit meter is.
from the PSU there is a 4 pin lead which plugs into the MB. (12v)
a 6 pin lead which i think plugs into the graphics card cos i cant see any other place where it would fit.
another lead goes to the cd drive, the FDD and the HDD. there are a few leas which are identical and dont appear to go anywhere, i assume these are for extra drives.

there's a 4 prong cdin socket but i dont seem to have anything to fit, although im sure my last rig did!

the box had the processor fan unit, and a small rectangle metal pad which i assume is the processor, or is that the pad your on about?

[Prof]

Originally Posted by Laffertytig

i woner if anyone here can help. ive just assembled a pc from scratch but it wont power up. surely the PSU should at least power up when i switch it on buy no nothing happens. for testing purposes i tried pluggin the old PSU into the wall as well but that doesnt even power on. i wasnt aware that the PSU had to be connected to the pc hardware to work. any ideas?

I must admit that I've never tried it, but I would expect the cooling fans to come on when the PSU is connected to the mains regardless of whether or not it's connected to the motherboard. It sounds silly, but is there a voltage selector (110/230V) or an on/off switch on the rear of the PSU (near the mains lead connector) which is in the wrong place? If the old PSU won't power on either, is there something wrong with the mains socket in your house?

also when installing the processor it said to apply thermal grease but i dont have any, is this a problem?

YES! Be thankful your PSU doesn't work. Don't attempt to turn on this PC unless you've got some paste in there. I'd recommend some Arctic Silver or something.

i assume it wouldnt have anything to do with the LED leads as the case i have which has the LED wired differs from the motherboard manual?

Try it with just the main power switch connected...when you know it's all working you can then plug in the reset switch, PC speaker, HDD light, power light, etc...

there's a cdin socket on the MB Which i could swear has something in it on my old asrock MB, should there somethin in there?

Only if you want digital audio from your CD-ROM. It's not essential. The connector will be a 4-pin small flat plug. Connect one end to the CDIN on the motherboard and connect the other end to one of your optical drives.

also, there's an 6 pin lead which comes out of the PSU but the only place i can see where it fits is the graphics card, is this correct?

That's the PCI-E power cable and yes, it should be connected to your graphics card.

In addition to the 12V ATX power lead (the one you mentioned) there should also be a 20- or 24-pin power cable from the PSU to the motherboard. It's quite important!

If you're worried about your PSU then you can buy a PSU tester from Maplin:

http://www.maplin.co.uk/search.aspx?...nu=y&doy=10m10

Having said that, they're quite expensive and if the cooling fans don't come on then there's probably something wrong. Have you checked the fuse in the kettle lead which connects your PSU to the mains?

the box had the processor fan unit, and a small rectangle metal pad which i assume is the processor, or is that the pad your on about?

If you used the boxed cooler which came with your CPU then there was almost certainly some thermal interface material already on the heatsink (it looks like a small square of Blu-Tack on the bottom of the heatsink)...if so, you don't need any extra thermal grease.

I don't mean to sound rude, but if you don't know what a processor looks like, are you sure you should be building your own rig? I must say your posts don't inspire confidence!

[Laffertytig]

haha yeah im no expert but i built my last rig last year and had no probs.

on the MB where the processor goes a lever lifts, the instructions said to place the seperate rectangle pad on the motherboard, then the fan unit on top it then secure. is that rectanglar pad the processor, or is that the thermal pad?

so the old PSU fan should start up when plugged into the mains? it didnt, and i used another socket

the power lead i use to the mains has a 5 watt fuse, is it possile that because i have a more powerfull PSU its blown the fuse and i need a more power fuse or something?

[Prof]

Originally Posted by Laffertytig

haha yeah im no expert but i built my last rig last year and had no probs.

on the MB where the processor goes a lever lifts, the instructions said to place the seperate rectangle pad on the motherboard, then the fan unit on top it then secure. is that rectanglar pad the processor, or is that the thermal pad?

That would be the processor The thermal pad (if it had one) would be a small square of grey squidgy stuff stuck to the bottom of the heatsink (the big metal lump with fins and a fan on top).

so the old PSU fan should start up when plugged into the mains? it didnt, and i used another socket

I've just realised that I've been talking nonsense! Sorry. Of course the fan won't start when it's not plugged into the motherboard! I don't know what I was thinking! Make sure you've got the power switch plugged into the right connectors on your motherboard. It's worth checking the manufacturer's website to see if there was a mistake in the manual. I've built a system (many years ago) where the printing on the motherboard, the manual AND the 'correction' to the manual were ALL wrong about where to put the power switch!

the power lead i use to the mains has a 5 watt fuse, is it possile that because i have a more powerfull PSU its blown the fuse and i need a more power fuse or something?

I can't imagine your PSU drawing more than 5 Amps (not Watts!) from the mains unless it's broken. Still, it's worth trying a different fuse (or a different lead if you don't have a spare 5A fuse handy).

I've had a look at your system specs and you have built a high-end system powered by a very cheap PSU. Big mistake, if you ask me. A decent system will need a decent PSU to run properly. Although it might say 550W on the case, it might not be able to supply enough power on the 12V rail to power your GFX card.

Still, I would have thought it would at least turn on!

[SUBMAN1]

Originally Posted by Prof

I can't imagine your PSU drawing more than 5 Amps (not Watts!) from the mains unless it's broken. Still, it's worth trying a different fuse (or a different lead if you don't have a spare 5A fuse handy).

I've had a look at your system specs and you have built a high-end system powered by a very cheap PSU. Big mistake, if you ask me. A decent system will need a decent PSU to run properly. Although it might say 550W on the case, it might not be able to supply enough power on the 12V rail to power your GFX card.

Still, I would have thought it would at least turn on!

Nope, you will get 0 life if the PSU is not able to power the system. It will refuse to turn on at all.

By the way, my PSU has a 55 Amp inrush voltage, so I have popped 15 Amp circuit breakers on occasion for simply plugging my system into the wall! In my old place, I never dared unplug it since it was a pain to keep resetting the house circuit breakers until the inrush voltage was finished.

-S

[Prof]

Originally Posted by SUBMAN1

Nope, you will get 0 life if the PSU is not able to power the system. It will refuse to turn on at all.

Interesting...I would have thought that the current draw from the GFX card on start-up would have been small enough that the problem would only be apparent when the GFX card started drawing peak current (i.e. when running a 3D game).

By the way, my PSU has a 55 Amp inrush voltage, so I have popped 15 Amp circuit breakers on occasion for simply plugging my system into the wall! In my old place, I never dared unplug it since it was a pain to keep resetting the house circuit breakers until the inrush voltage was finished.

I believe you, but I can say I've never had any such problems on any of my systems using standard 13A fuses and breakers. 55A is crazy!

[FIREWALL]

I didn't notice anyone else ask.

But, have you been wearing a ground strap or a least been grounded to case during the assembly ?

God I hope so.

[SUBMAN1]

Originally Posted by FIREWALL

I didn't notice anyone else ask.

But, have you been wearing a ground strap or a least been grounded to case during the assembly ?

God I hope so.

I can happily report that I tried one back in 1993 as a fasion statement (actually, was helping out a PC builder at the time for the day) - for about 2 minutes, before I ripped it off! Before and since then, I have never owned a ground strap and have yet to fry a PC component - in all the 10's of thousands of components I have touched (used to be in the PC biz for a while way back when), nor any of the 20+ PC's I have owned over the years.

Don't get me wrong, its good prevention against not thinking about grounding yourself out before touching things (simply touch the case of the PC you are working on, or if it is external components, work on top of an anti-static bag), but not neccesary after it becomes common practice to automatically grounding yourself prior to working.

Though possible, I think it would actually be hard to really fry a component with static electricity.

-S

[SUBMAN1]

Two things off the top of my head-

1. Get some Arctic Silver and DO NOT TRY TO TURN YOUR SYSTEM ON WITHOUT THERMAL GREASE!!! Put the Arctic Silver between your cooler and your CPU. If there is no contact mechnism, you will have very inefficient heat transfer and you will eventually make yourself an expensive paper weight out of your CPU because of it.It will litterally burn itself up.

2. To check your PSU, unplug your video card from the system and check if it powers on. That PSU you showed may have wattage, but may not have enough amperage on the +12 volt to kick the system on with the video card in the system. If the system turns on without the video card in the system, your PSU does not have enough power.

-S

[Laffertytig]

so just to get things straight, the pad i placed on the MOBO IS the processor then, and the other item thats placed on top is the fan unit? i seem to recall the athlon 64 processor i installed last year already had paste on it. shouldnt this paste be supplied with the unit?

il try your 2nd point when i get home as im using my work pc right now. last year i had a laptop so i was online gettin help as i was building it but this im on my own building it

[SUBMAN1]

Originally Posted by Laffertytig

so just to get things straight, the pad i placed on the MOBO IS the processor then, and the other item thats placed on top is the fan unit? i seem to recall the athlon 64 processor i installed last year already had paste on it. shouldnt this paste be supplied with the unit?

il try your 2nd point when i get home as im using my work pc right now. last year i had a laptop so i was online gettin help as i was building it but this im on my own building it

If you did have a thermal tape on your CPU cooler, then you should be OK. Its not as efficient as something like Arctic Silver, but it will do the job.

-S

[3Jane]

Not sure if this is the same issue. But a while ago I had something similar to a new machine I had put together. It turned out to be simply that the 'kettle' mains power lead was not quite making full contact with the p.c power-source. This lead had been in use before, but I was using a new power-source with a fractionaly smaller socket. If your system had run for a while then shut down, that would indicate a temperature issue, but that doesn't seem to be the case. You still need thermal paste though .