Cold Power - Laptop motherboard is bad or is it?

Here is a tip to all the people whose laptop will not turn on. I have had customers pay $300 to get a bad diagnosis on laptop that will not turn on.
::Cough::Tech Room in Newport Beach::Cough::

I got a laptop to sell on eBay from a client who had a laptop diagnosed as having a bad motherbaord and not worth fixing. I do not know why the client did not take the laptop to me in the first place but it was probably a good thing in the long run. It turns out that the power supply did not supply power anymore. The DC jack was not defective nor was the motherboard faulty. If the technician would have bothered to touch the power supply, after an hour of being plugged into the wall , the technician might have noticed the power supply was cold. ..

I ordered a $30 power supply(off eBay) for the Sony Laptop and presto, laptop turneth on.
I think the concept the helps out is that electricity gives off heat.(exothermic) If the power supply is working it should get moderately warm. Some get hot!

I have used this same theory to help a customer whose scanner was not working anymore. The AC Adapter(power supply) was not getting warm. On closer inspection, the ac adapter was falling apart.
Before one assumes a Laptop's dc jack or motherboard is bad there should be some evidence. I.E. the DC jack might wiggle or the laptop has a burning smell etc.