Failing power supply

[#1]

Before I go ordering a new power supply for an E Machine 330 I'd just like to check if anyone may be familiar with this problem.
When I switch on the mains a green light on the back flickers on momentarily and then theres nothing.
It's smaller than the usual standard ATX power supplies otherwise I'd have no problem finding a second hand one for next to nothing
Its a Bestec ATX-1523F 150W
Is anyone familiar with this problem?
Would you say that it's completely dead or can it be serviced?
Thanks

[#2]

Yes that's a sign it's failing alright - mine did the same.
I personally don't think they are worth servicing for what a replacement costs.
i've got a E-machines 620 i'll cross reference the model numbers, if the one in my machine is the same or simular and fits your machine your welcome to have it - it's been sat dormant for a few months but works fine
i'll let you know

[#3]

PJ, we are talking about an old PC here so 150W is more than adequate for its use. It must be because that is what the manufacturer supplied with the unit and up to now has worked as designed.
Julia,
Having said all that I have found a slightly higher spec replacement here, item 13 @ £24.50 + £8 P&P which states its a replacement for the one you have. You may be able to source it cheaper if you look around for it.
[edit] Or this one which is a generic PSU.
I believe the PC uses the Micro ATX PSU specification so any generic PSU of that type should fit but it depends on things like where the CPU & headsink are, other components in the case etc so you can never be 100% sure if a more generic PSU will actually fit.

[#4]

Juliasdream, your old power supply box does sound like a Micro-ATX format psu, as Peter says. If it has all of the following, then it is almost certainly a generic Micro-ATX psu ...
1) The psu case dimensions should be 125 x 100 x 64 millimetres
2) The mounting screw holes and A/C inlet should be on one of the 100 x 64 mm faces of the psu case.
3) The cables for the motherboard and discs should exit though the 100 x 64 mm face opposite the A/C inlet.
Some of the big name computer manufacturers deviate from the standard by moving the mounting screw holes, cable outlets or psu fan. In which case there is a high probability that you will not be able to install a generic Micro-ATX psu. It would be safest if you could take the old psu to a shop to compare new with old.
As already mentioned above, you should be able to pick-up a generic Micro-ATX psu from almost any computer parts supplier.
Alan.