Computer Power-On Switch problem (1 Viewer)

[rogerscoth]

I have been using my self-built computer (with an Asus Motherboard and Windows XP Operating System) since December 2004, and have had no serious problems until a few weeks ago.
When trying to start up, by pressing the power switch button, sometimes it will start straight away, but mostly needs from 10 to about 30 or more presses before it powers up. Firstly, I suspected the switch, but have changed the small switch with the connected lead to the motherboard pins with no success. I used the switch/lead from my previous computer, but I could not swap the PSU, as it did not have the same motherboard connector.
Could someone tell me if the switch triggers a unit on the motherboard to set the Power Supply Unit working, or is the trigger within the PSU itself?

Roger

 

[will@bill]

I have been using my self-built computer (with an Asus Motherboard and Windows XP Operating System) since December 2004, and have had no serious problems until a few weeks ago.
When trying to start up, by pressing the power switch button, sometimes it will start straight away, but mostly needs from 10 to about 30 or more presses before it powers up. Firstly, I suspected the switch, but have changed the small switch with the connected lead to the motherboard pins with no success. I used the switch/lead from my previous computer, but I could not swap the PSU, as it did not have the same motherboard connector.
Could someone tell me if the switch triggers a unit on the motherboard to set the Power Supply Unit working, or is the trigger within the PSU itself?

Roger

had same prob it was power supply

 

[Duke Leto]

its a little of both, you can't power up a PC unless the motherboard connections are okay as well as the PSU

 

[IanF]

Mine was the power supply as well rather than the switch. After replacing it there was no problem at all.

 

[will@bill]

I have been using my self-built computer (with an Asus Motherboard and Windows XP Operating System) since December 2004, and have had no serious problems until a few weeks ago.
When trying to start up, by pressing the power switch button, sometimes it will start straight away, but mostly needs from 10 to about 30 or more presses before it powers up. Firstly, I suspected the switch, but have changed the small switch with the connected lead to the motherboard pins with no success. I used the switch/lead from my previous computer, but I could not swap the PSU, as it did not have the same motherboard connector.
Could someone tell me if the switch triggers a unit on the motherboard to set the Power Supply Unit working, or is the trigger within the PSU itself?

Roger

do what i did get a good mate to lend you his power supply try it and see:t:

 

[rogerscoth]

Thankyou all for your prompt responses - I quite suspected the problem to be the PSU, and they are cheap to replace.
I am at that point now where I am considering building another (up-to-date) computer with a Core 2 Duo CPU, as my current one seems to be a bit slow - provided that the BOSS allows!!!!

Roger

 

[rogerscoth]

I have just fitted a new quiet 450W PSU (£15-80 inclusive of p&p), and that has solved the problem. My next new-build will be a little later now - that is if nothing else fails!
Once again thanks for all your responses.

Roger

 

[Corax67]

Our desktop did exactly the same & it was the PSU, local PC shop did the swap for £15 & sorted.

 

[Guidenet]

Just my opinion, power supplies are one of the least considered items when building a new computer or replacing a bad PSU. IMO, its one of the most common reasons for system failure.

A power supply does a lot more than just changing AC power to usable DC at various voltages. It smooths the power. You look at well designed, expensive power supplys and you see that they're heavy with large capacitors and big heat sinks. A PSU changes alternating current to pulsating DC current. Think of it as chopping off the tops of the sine wave and filling it in at the valleys. Capacitors are like batteries. They store the pulses and fill the valleys, trying to make a smooth DC signal.

The larger the caps, the better the job it does. Computer components are very fragile and suseptable to current spikes, especially those provided by cheap power supplies.

Personally, I wouldn't consider a power supply that costs less than one tenth of my system cost, in an inexpensive system. More often than not I spend $100 or more on a PSU. Tagen is one of my favorites. It's a 480 watt psu with 26 amps on the 12 volt rail. This is one reason I get very few, actually none, PSU failures and very few component failures. For example, this machine is running a pair of 10,000 rpm Raptor hard drives in a striped RAID 0 array. They've been running pretty much 24/7 for over 2 years without failure. Smooth power is important, IMHO. I'd go cheap on something less important, if it were me. Everything hinges on a good PSU.

If anyone is really interested, there's a good link here.

http://www.uic.edu/classes/ece/ece340/experiments/diode_exp/al.diode.exp.html