Power supply trouble??

[meebers]

A standby machine that I have is having trouble starting. When first turned on, it will attempt a start, drive lights fans etc come on then within 3 seconds, go out and repeat. This does this for about 5-6 iterations and then starts normal and will run until turned off. This system has one HDD, one DVD drive, MB graphics, so I don't think there is much of a load. Just wondering if the power supply is getting old and cranky!

 

[Wrenches]

How old and what brand/model is the PSU? It does sound like there's not enough juice to push it.

 

[braddersz]

Sounds like powersupply to me.

However, have you tried draining static energy from the motherboard.

When pc is off, remove power cabel, and then try turn the pc on 5 times, put power cabel back in. Ot should boot first time.

If it does it again, change psu

 

[Layback Bear]

I have also seen this happen with a weak motherboard bios battery.

 

[meebers]

Thanks for the reply. The power supply make is Antec and is called a "true Power 550". 550 watts. It is about 6 years old. After numerous days of this happening and when it finally starts, I always get a message that the computer is now in Safe Mode and to push F1 to start. (probably from the numerous starting and shutting off sends it into Safe Mode??) F1 starts it and it continues to run, very very stable. It reminds me of the Energizer Bunny, it just keeps going!. At first I also thought maybe the cmos battery has finally given up the ghost and so I installed a brand new fresh one. The problems continue. I have given the PS a smell test, it seems normal. Unplugged and inspected all power connectors, they look good, nothing burnt etc. If only I had a 6-8 channel oscope with memory, I could watch the boot up, the voltages etc and see what is happening but I don't. It is interesting about draining the mother board. This computer is connected to a UPS, and even though the computer is shut down, the computer has a digital display on the MB that reads "99" in the shut down mode, and the router reads the lan card as connected always. If this is a problem that has manifested itself in the last month or so, I will start turning the ups off and see what happens even thought it has been connected this way for years.

 

[Layback Bear]

Remove your computer from the UPS for a period of time and see if the problem goes away.

 

[essenbe]

Good suggestion Layback, a weak battery/malfunctioning in the UPS could cause the same problems also.

 

[mbratch]

One thing that can occur, certainly after 6 years, is that some solder joints can form very fine cracks, making some of the joints intermittent dependent upon temperature. The supply can otherwise appear to be normal (fans, etc). I always keep one spare new supply around to test with for cases like this. And then if it is the supply, you have one there to put in.

 

[braddersz]

If the motherboard battry had failed. Windows time and date would reset every time you turn it on.

DId you try my suggestion in my first post?.

 

[meebers]

Further testing. I unplugged the cord from the rear of the power supply for several hours (attempted to start several times) and then bypassed the ups also (straight into the wall). The results so far over the past two days is 1 failure and 2 passes using the above configuration. 3-5 business days the new PS should be here

 

[braddersz]

Further testing. I unplugged the cord from the rear of the power supply for several hours and then bypassed the ups also (straight into the wall). The results so far over the past two days is 1 failure and 2 passes using the above configuration. 3-5 business days the new PS should be here

Sweet. Which PSU did you go for