Got me puzzled !!

[I4n]

This is a problem thats got me puzzled so hope somone can stop me scrathing my head and getting splinters:rolleyes:

The PC I am working on for an aquaintance had a dead power supply due to a shower tray leak above the machine. It was only switched on at the wall, not running. I proved the machine was O.K. buy using a spare power supply that I had and machine runs O.K. The power supply that I used to check with was the "wrong" form as it's a mini ATX and the machine requires an ATX.

I put in a new ATX from Maplins and the machine did not start at all, I suspected a duff unit and returnred it, Maplins checked others from the batch and found more faulty so refunded me. So far so good, I then went to my local independant computor business and they supplied me with a new ATX power supply but this is doing just the same, the machine will not start up when the power on button is pressed, I have just put the mini ATX back in and the machine powers up :confused::confused::confused:

 

One other thing, with the new Power Supply, as the power is removed, the case and processor fan give a little twitch :confused:

Tech details as follows:-

MoBo is Foxconn UYF64409640 PC RC4107 MA-RS2H D3

CPU Intel 3.2 GHz

Ram 960mb

OS XP SP3.

Original Power Supply ISO Model ISO-400PP4

 

New Power Supply EZcool Model ATX-450JSP 450w.

 

Mini Power Supply that will make the machine run is COLORSit ATX12v M0300U.

 

 

Any idea's anyone?

[Guest Wolfeymole]

A shower tray leak?

 

Do you mean the water came through the ceiling Ian?

[I4n]

Yes, it got wet and took out the power supply, the water has not affected anything else as I can get the PC running and use it with the mini ATX power supply but not the brand new replacement, thats why I'm puzzled !

[Guest Wolfeymole]

If the PSU was located at the top end of the tower like most are then the water could have pooled and dripped down the cables and caused all manner of issues on the board without totally screwing it.

 

Just a thought.

[I4n]

If the PSU was located at the top end of the tower like most are then the water could have pooled and dripped down the cables and caused all manner of issues on the board without totally screwing it.

 

Just a thought.

 

Yes I know what you mean, I am an Electrical Technician by trade so understand what your saying, what I can't understand is why the flamming thing will work perfectly with the mini ATX but not 2 different new ATX ones !

[Plastic Nev]

Hi Ian, the only thing I can see now is some possible connection differences, I suggest digging your multi meter out of your work tool box and checking the voltages on the connection pins, see if there are any differences between the two PSUs.

[I4n]

I can see what you are saying Nev but the new PS does not switch on so voltages not present to read. I have wasted too much time on this machine (got a motorbike to rebuild :) ) so I have fitted the mini ATX and made a cover plate for the gap, it gets returned tonight, don't you just hate it when there is a mystery unsolved :o

[Plastic Nev]

Hi again Ian, a standard ATX PSU should start up if you short pin 14 (green) to any black ground pin on the 20 pin molex connector.

[I4n]

Thanks for that, I will certainly keep that in mind for the future, as I said earlier, machine was returned Friday night and I have not heard one way or other from recipient so assume all is well. Perhaps one day I can get it back and delve a little deeper.