"Vivek.M" wrote:

My computer gives me a shock; Some details:
Supply: 250 V/50 Hz.

Surely you mean 230V ?


Neutral to Ground at plug-point: 4-5V.
Power On (UPS), but no equipment drawing power: 9V (Computer-case to
Earth).
With everything powered ON: 20V (Case to Earth).

There's clearly something wrong there since a case should normally be earthed.
But even so - you shouldn't notice even 20V.


Everything ON: 5V (Earth to Neutral at powerstrip - before the UPS).

The neutral voltage is higher than I'd normally expect to see but nothing out of
order.


My UPS batteries are very weak and give about 4-5 minutes backup on
power-failure. Could this be causing the problem?

No.

How do i check to see if the battery is dead?

Do you have a voltmeter ? Check its voltage during the discharge cycle.

Are you sure you're not simply getting 'static electricity shocks' when touching
the PC ? Do you have carpets with synthetic fibre for example ? Do you tend to
wear clothes with a high synthic fibre content ? These are all things that wil
charge *you* up and the PC wil simply *discharge* you when you touch it.

Graham