cuky2000 thank you for your reply.
I had'nt realised there could be several reasons for this.
The intermediate texts in electrical engineering I've looked at don't have the answers.
Do you have any suggested references on the web ?
Sorry, I had'nt read you subsequent message, which states that the chips are mostly mounted on sockets with standard logic.
In that case, I would suggest you have a go!
Since the devices are easily available and can be easily replaced its worth a try. All you need is some diagnositc software...
You don't state the complexity of the boards or the generation of technology employed.
However assuming they employ Surface Mount and Ball Grid Array packaging, the two aspects to be considered are fault finding and component replacement.
Many Board manufacturers provide Diagnostic Software...
In AC Power Transmission, what is the reason for earthing the Neutral?
For in principle at least, it would be possible to Transmit AC Power with a floating Live and Neutral.
Philiptechie
