PSU problem?

[zak_swan]

My PC has started not booting correctly there is one click and PC freezes i reset once or twice and when PC does start it works fine all day till i try to boot next day.
Ive done all the usual stuff anti virus etc and ran Maxtor Power Max which says HD is OK
I've been googling and the PSU may be the problem.
The PSU says 400W but it's a cheapo.
I've got a 6600GT which is a bit power hungary.
Everest shows these voltages
CPU core 1.63V
AUX 1.49V
+3.3V 3.31V
+5V 4.92V
+12V 12.71V
-12V -12.77V
-5V -5.65V
+5V Standby 4.97V
VBat Battery 3.22V
I've got AMD 3000XP
Could it be PSU or something else?
when cpu running at 100%
everest shows these
cpu 1.63V
aux 1.49
+3.3V 3.31V
+5V 4.89V
+12V 12.89V
-12V -13.02V
-5V -5.75V
+5V standby 4.97V
VBAT Battery 3.18V
are these way out?

[isogonic]

another possibility:

http://www.badcaps.net/

[zak_swan]

thanks for that isogonic, that does look like a possibility.