Computer won't start-why?

[Flightsim]

I've had trouble getting my computer to turn on lately and I can't figure out why. Sometimes I press the power button and nothing happens. If I hold the power button down for awhile it turns on sometimes. I've also tried turning my power supply off and on and that seems to help as well. Does this mean my power supply is the problem? Once my computer turns on it never shuts off, so it seems like my power supply is fine. Would my computer not turn on at all if the power supply was bad? My power supply is a 430W Enermax, I can't remeber the exact model name. Could my HD be the problem? It seems like it doesn't spin up like it should when I press the power button. I would appreciate any ideas on what might be causing this problem- its very annoying.:|

 

[Slogun]

That's the sort of intermittent problem that can be hard to diagnose.
I would not expect a nice enermax to be the first likely source of the problem.
First line of troubleshooting would be to make sure that all electrical connections are tight such as those between the power switch and the mobo.
The contacts on the power switch itself should also be checked.
A power switch is nothing more than a momentary contact switch. The leads for it (2 leads) run to the mobo. If you short those two pins on the mobo and the computer turns on each time you do that, then the problem is in the switch/connection assemply. Conversely, if the comp still only turns on intermittently, the problem lies elsewhere, such as the PSU or a connection between PSU and mobo or some other component.

This is a time when it would be helpful to have a second PSU, even a cheap one, to swap in for testing.

 

[Flightsim]

This is a time when it would be helpful to have a second PSU, even a cheap one, to swap in for testing.

That's what I thought, I might just buy a new PSU for testing. If my old PSU is the problem, I'll keep the new one, otherwise I should be able to return it. It could also be a problem with my mobo connections, but I'm buying a new mobo soon anyway. I'll check the connections like you said, but I doubt they came loose or something. Is my HD a possible cause for this?

 

[Booster]

It's a memory problem. Run your PC with 1 stick of RAM and it'll be fine. I had the same kind of problems with my ECS P4S5A/DX+ moboard, but when I removed the second RAM module it cured it and now the system is rock solid. Also, updating the BIOS might help as ECS resolved that issue in the latest BIOS by prolonging the POST time <---- I'm not at all sure in it, though. But I don't care any more.

 

[Flightsim]

It's a memory problem. Run your PC with 1 stick of RAM and it'll be fine.

I don't think so. I only have 1 512MB stick of RAM in my mobo. My mobo isn't ECS either, its an Asus P4S533.

 

[Booster]

Originally posted by: Flightsim

It's a memory problem. Run your PC with 1 stick of RAM and it'll be fine.

I don't think so. I only have 1 512MB stick of RAM in my mobo. My mobo isn't ECS either, its an Asus P4S533.

That ASUS board has exactly the same chipset as mine, and these cold boot issues are bound only to SIS-based motherboards, especially the 645 series. It's a memory problem, believe me. Try using a different RAM stick, one bank instead of two-bank one. Run it at normal, non-turbo timings (maybe your module can't support them properly). SIS chipsets are very RAM picky.

 

[Slogun]

Sounds like you are making a lot of assumptions ( ECS, when its not, 2 sticks mem, which it's not).
I had a cold boot problem with one of my K7S5A boards, didn't behave anything like what the poster described.

 

[TD77077]

flightsim,

I have also heard of some RAM pickiness with the SIS motherboards. I have two Asus A7S333s that are pretty picky. I think I heard somewhere that the problem you describe can happen if the RAM is in DIMM1, but will often go away if you put the RAM in DIMM 2 or 3. Try it in different slots and let us know what happens.

Good Luck.

 

[DannyBoy]

Ive had soo many problems with my K7S5A and the SIS735 chipset + my memory.

Ive tried 1 stick o' this, 2 of that, 4 different brands of memory, a brand new K7S5A, and sitll its un-reliable

Cooling seems to be another issue with the board, of course thats probably not your problem.

Dan

 

[Insidious]

sounds similar to symptoms I had on a MoBo which operated with a failed Chipset fan for a while( a couple of days) before I found it. Unfortunately, the damage was permanent and I had to RMA it.

Luckily I was able to do the parts swap thingy to diagnose. I don't think I would have isolated the problem component otherwise.

 

[Flightsim]

What exactly is a "cold boot problem"? Is it the same issue I'm having? I've noticed that my computer usually has trouble starting up only the first time I turn it on for the day. It turned on right away the second time I powered it up today. Does cold boot mean "first-time"? My computer is about 7 months old and it never had this problem for the first five or so. I'm pretty convinced my PSU is the problem, but I don't know for certain. I haven't double checked my mobo/PSU connections like I mentioned earlier, but I'll try that tonight. I doubt my RAM(Cosair XMS PC2700) is the problem since I never had any issues with it before. Why would it cause a problem if it was running fine in the its DIMM for several months? I'll switch the DIMM around anyway and see what happens. As I asked before, could my HD cause any of this? Thanks for all the advice.

 

[DannyBoy]

Cold boot is a dead machine that wont boot. No leccy = no heat, therefore everything is cold

Dan

 

[Slogun]

Here is the info on the cold boot issue with some K7S5A boards (such as I had with one of my two K7S5A boards).

It does not result in a completely dead machine upon pressing the power button. The machine boots into an error screen.
According to the info in the above link, cold boot issues are not a result of bad memory, but will result in a problem with a misread of memory.

With my K7S5A board (read SIS 735 chipset) the cold boot problem was fixed in the BIOS by setting the CPU Speed to 138 as opposed to 133 which slightly overclocks my 1400 MHz Thunderbird to 1450 MHz which creates slightly more (faster) warmup upon bootup circumventing the cold boot issue.

The problem that Flightsim describes does not sound like cold boot issue.