It sounds as though there is a problem with the DC socket on the mobo. Some of these are easy to change as they are connected by a mini harness. Others are trickier (ie, more expensive) as they are soldered in. The problem with the other laptop is unrelated, and I've never come across a virus that can have any effect on the charging circuitry.
Basically I have a very specialized ruggedized laptop(Endura Notino R5500), it was fine until it would only charge if I put its adapter in an awkward position. I sent it in for repairs(under warranty) and all they did was cut of the end of my adapter and I suspect probably solder a new end on (even though my adapter is not under warranty and they were supposed to look for internal problems).It was O.K but the same problem came back after 2 weeks with the 'new' adapter (which was clearly my old one)and before I sent it off again I ordered a new adapter and battery, just in case it might have been both that were at fault and put them into the laptop, it still has the same problem.
I thought this may be a power jack/motherboard problem afterwards because it still only has power in the most ridiculous awkward positions,but,whereas before it actually charged when put into this position now it is not even charging, both my old absolutely fine battery/and new battery. I wonder whether it may be some tricky virus as well. However I don't think so as windows does not even have time to boot. It may also be a jack AND battery pin problem. It could be the case that I was at fault as the awkward position my adapter had to be in to charge (which basically involved tugging at the end of it) lead to internal damage.
The reason why I suspect a virus may also be at play is another laptop in my house has the same charging problem,but not the problem of the adapter having to be put in a specific position(this happened suddenly).Can you please tell me what may be the problem so that I can specifically ask them what to do,and then they would have no excuses, because I have already spent 100+ on hard to find battery and adapter I think I will pull my hair out if they send it back like this again...
By what you have said so far, I strongly suggest the contact on the jack socket is at fault.
I would suggest as a start to get yourself (or borrow) a voltmeter tester and check that the charging unit is actually supplying power to the plug. Normally on a jack type power plug the centre is positive (+) and the outside is Negative(-) and that is at the correct voltage.
If this is OK then you need (depending on your confidence level) to test the jack socket (inside machine). The easiest option is to get another power plug undo the cover, so you can see the terminals and plug it into the computer. you can then use the voltmeter to test to see if there is any voltage actually at the socket.
The next part is tricky.
Normally the socket contains 3 terminals with the centre one being a switch that activates the charging mode.
If the internal socket is damaged (as seems likely) you will either need to get a new socket and replace it yourself, or take it to an electrical engineer to be replaced.
It could of course be something as simple as the plug that was soldered on has come un-soldered. easily done with handling and/ or moving the laptop while connected and needs resoldering.
Please ignore the last sentence as I see you have covered that by buying a new unit.
This thread is now locked and can not be replied to.