Dell Vostro 430 Problem

Failure symptoms of my Dell Vostro 430 Desktop


1) With all accessories plugged in, [mouse/keyboard/camera/speakers/screen /printer/Wi-Fi ariels], and powered on, power switch shows Amber Light with fan sounds for CPU (running at high speed)/Power Supply Unit /Graphics card. Power switch switches off and goes blank for 10-20 seconds and repeats switching on amber for 20 seconds then switch off for 20 seconds and then switches on with amber light continuous. Mouse light on/screen remains blank [separate power source])

2) With all accessories unplugged, except keyboard and mouse. Power on switch shows amber light/ mouse shows red light / keyboard is dead. All cooling fans operating at high speed. Replaced keyboard still dead. Screen switch shows amber light and “NO VGA CABLE”. Connected VGA cable and screen turns black/blank [No vga cable advice notice now disappeared], with screen blue light turning to amber [power saving mode] after 5-10 seconds. Power self start and stop repeats as before

3) All power off [PSU Incomer unplugged] and left for 1 minute then start button pressed for 10 seconds. {No reaction from Fans } Tried repowering PSU for same result.

4) Removed CPU from Base and replaced cooling transfer paste. Re-connected PSU Cable. No difference to 2) above.

5) Changed Mother board, [I had previously bought a spare when Dell Service Contract finished], re-seated all back into place and repeated all the above tests for the same results.


SO WHAT IS THE PROBLEM??

a) The PSU faulty?

b) The CPU?

c) The screen?

d) The Graphics Card, [replaced approx. 2 years ago and fine ever since]?

I need some pointers to enable me to solve the problem, OR I bite the bullet and just replace my 14/15 year old machine?

 

OK guys, thanks for your thoughts, I'll try swopping out the PSU.