Vaio thats locked up

First off hello to everyone it's been a while since I've logged into the community but I'm in need of help and this is the largest knowledge base I know and trust.

Vaio Model#: SVE141D11L 8GB RAM 750GB HDD Few years old and in fair condition. General wear and tear. 

The issue: My friend has a Vaio that seems to be locked up on a software or BIOS level somehow. Through searching online this apparently seems to be an issue that happens with them but the typical fixes havent worked.

Circumstances: She was using the laptop in a normal capacity with no issues at all. The battery died while she was out in town with it, she then stowed it in its case and when she got home she plugged it in. The first sign of issue was that the orange charging light did not come on when it was plugged in. The laptop will not power up on AC adapter nor on pure battery power alone. You can hear the HDD spin up like normal then power down 5-8 seconds later when the AC adapter is plugged in but pressing power has no effect nor do any lights come on. 

What I've tried: I've checked all electrical connection points. The charging port gets power as well as the mobo. I have removed the HDD, RAM, and CMOS battery in an attempt to see if one of those may "reset" the mobo or clear whatever may be locked up. The HDD operates fine and works in another unit same with RAM. Installing another HDD and RAM into her unit leads to the same issue of not booting up and no lights working. I tried the Sony recommended procedure of removing all power sources and holding the power button to discharge any remaining juice and that has not worked. 

Any suggestions from the community are appreciated and welcome I do not know what else to try at this point and my knowledge of problems like this is pretty limited. 

 

dead laptop battery?

I thought that but it won't function even with the charger plugged in. I also checked the charger and tried mine which is the same charger. 

Have you tried powering it on with the charger in and the battery out?

+1  do this and hold in the power button for 5-10 seconds then put the bat and charger back on. then try to power up

Tried both and still nothing. When the AC adapter is plugged in with battery in or out you can hear the HDD spin up though. No lights or semblance of function happen it just spins up then back down. 

The thing that's the biggest bother is that the charging light will not come on. I thought there could possibly be a loose cable going to the mobo or a loose pin somewhere but everything seems to be functioning properly there.

bump

Well, If nothing works the Mobo is probably damaged in some way and the most

reasonable thing would be to sell everything you can salvage and get a new one,

or buy a new Mobo somewhere and hope it works (too expensive),

 or send it in and let them replace the Mobo or whatever is wrong ( way way too expensive),

 or try to repair the Mobo (not expensive but time consuming + may be futile) bye e.g.

replacing the bios chip (probably your best hope), looking for and fixing something broken (capacitor, Motherboard fuse etc.),

fixing a short circuit (metal contact, bend board etc.) or finding and fixing a problem with the power delivery (requires  a multimeter).

Good luck.