Boot Problem

[ahmadumair]

Hi Guys. I got this PC for repairing from one of my neighbours
Specs:-
Intel 845GVSR MB
Intel Pentium 4 2A GHz
2*128MB DDR Memory
VGA built in
HD Seagate Barracuda 40Gbytes 7200.7
125W LUNAR ATX-200 P4 PSU

Problem:-
This PC was working for years until recently when it developed a habit of not booting at the first attempt after power was switched on(Processor fan no spin,PSU no spin, HD no spin,MB Light on though).After Waiting for 15 mins the CPU fan starts to spin as long as you hold the CPU Power Button(I am still tempted to think that something charges in those 15 mins) And still after waiting for some time it would respond immediately to the power button.As long as power was plugged in the wall it would work properly(Reboot infinitely, shut down and boot again) but once the Power plug was removed from wall socket It would the same thing next time. Tried changing the CMOS battery to no avail . I think it is the PSU or the Case. MB works properly coz once it boots everything works fine.What should i do??

 

[Corbin]

This is so confusing you put as long is its plugged in.... I'm soo lost in this. Did you try a different power supply? Do you have tools to test the power supply? Did you have any beep codes? When its plugged in what pops on the screen any bios? Some computers don't run there fans until the hdd is booted to a os. Can you boot into a live disc like ubcd4win? And I may be dumb when did cpus ever have their own power buttons?

 

[RegEdit]

Use one of these

http://www.newegg.com/Product/Produ...re=power_supply_tester-_-99-161-001-_-Product

Or swap out a known working PSU

 

[ahmadumair]

Sorry. I know i am a little too much confusing(Isnt that confusing). ;-).Here are some clarifications
1.The plugged in part:-It means when the power cable from the PSU to the wall socket is plugged in both sides and the switch on the wall socket is ON.

2.CPU Power Button:-That is the main power button which is on the case.The one which we press to turn the computer on.

3.No i dont have the tools except a Digi MultiMeter.

4.I can boot into UBCD4Win but not any of the bootables in my SARDU disc.

5.No Beeps nothing. I told you before that once it turns on everything works fine, albeit it is very slow,slow even 4 a P4 with 256MB Ram.

6. It simply doesnt turn on, no fans, no screen, nothing.

7.After around 15 mins with the power plugged in(Read point#1 if confused) it responds when you keep the Power button on the computer pressed the fan starts and keeps running until you leave the power button. Before that its no fan nothing.

 

[TechguyUK]

I had something quite similar the other week. It was the PSU.

Change it out for a known good one and report back.

 

[iptech]

What should i do??

What have you already done to diagnose this problem? Have you tested the PSU, have you tried a substitute PSU?

You need to work on your diagnostic skills if you plan on doing this type of work for a living.

 

[ahmadumair]

I tested the following:-

1.all cables

2.PSU with a Dynatek DMM

3. tested as barebones

4.Case Wiring(visually and by testing it with DMM whent the power button was pressed

.@iptech: I have these skills all right but i am biding on time for spare parts and subsitutes(Even that DMM was client's)

.The problem is temporarily solved and my client is happy with it(He didn't want to
spend any money.I should probably have dropped him but i can't " 'cause he is an ol' friend o' my dad's".The client himself is an electrical engineer. I solved the problem by trying to manually start the computer(By shorting pin 14 on the PSU-MB cable with ground. When that was done, the client himself suggested that he'd make a switch out of it as he did not want to spend money.

 

[ahmadumair]

Problem permanently solved.Got my spare PC today. turned out that the PSU was gone bad(Leaking Capacitor.Client still says he will just replace the capacitor instead of replacing the PSU) x-{ OMG!!