Dear all.
New to forum so bear with, also please advice if other forum or sites may be more appropriate.
Dell Inspiron Pwr failure - the external PwrPack led goes out when plugged into the laptop and only comes back on when taken out of laptop and then reconnected to mains outlet. General Web chat indicates the pwrpack switching off due to a short on the motherboard and suggests a replacement of motherboard thereof.
multimetre testing for pwrpack indicates 20.3 volts output.
Stripped laptop (Inspiron 15R N5110) to component parts, Input pwr comes to a seperate I/O board which in turn connects to motherboard.
There is no obvious signs of burnt IC's / resistors / capacitors etc, to indicate possible short.
Q1) Could pwrpack still be faulty and needs testing under load?
Q2) in isolation, if I/O board is OK, should pwr remain on?
Q3) is it possible to test IC's / resitors on PCB to detect a short i.e. ohms resistances etc if item is shorted?
Dont want to pay over the odds by replacing i/o and motherboard if fault can be isolated to one or other or pwrpack etc
Thanks in advance.

New to forum so bear with, also please advice if other forum or sites may be more appropriate.
Dell Inspiron Pwr failure - the external PwrPack led goes out when plugged into the laptop and only comes back on when taken out of laptop and then reconnected to mains outlet. General Web chat indicates the pwrpack switching off due to a short on the motherboard and suggests a replacement of motherboard thereof.
multimetre testing for pwrpack indicates 20.3 volts output.
Stripped laptop (Inspiron 15R N5110) to component parts, Input pwr comes to a seperate I/O board which in turn connects to motherboard.
There is no obvious signs of burnt IC's / resistors / capacitors etc, to indicate possible short.
Q1) Could pwrpack still be faulty and needs testing under load?
Q2) in isolation, if I/O board is OK, should pwr remain on?
Q3) is it possible to test IC's / resitors on PCB to detect a short i.e. ohms resistances etc if item is shorted?
Dont want to pay over the odds by replacing i/o and motherboard if fault can be isolated to one or other or pwrpack etc
Thanks in advance.