XPS M1710 won?t power on

I have read several posts about this but none seem to be exactly the same as my problem, so forgive me for posting again.
Laptop was on working fine, I left it for maybe 20 minutes when I come back to it, it was dead. I tried powering on again but nothing. I tried a different power supply and tried with and without the battery. Same result. When plugged in I get the battery light flashing to indicate there is power, the power light on the supply is also on. When I push FN and power, I get NO lights in the Lock LED’s and the laptop dies in seconds as does the power supply, the led on the power supply goes out instantly, I have to unplug it, leave it for a few seconds then plug it back in and the power supply led comes on again. The only LED on the laptop that flickers for a second before dying is the wifi.
Laptop is about 4 years old and is out of warranty. I look after it really well and haven’t replaced any parts recently. It’s on a docking station and never moves anywhere. (I have done all tests off of the docking station and directly connected to the power supply)
Any ideas anyone? Please.

 

Had this happen under warranty and they replaced the motherboard and I think eventually the CPU as well. It had to go back to the factory and I know for a fact they replaced the mobo, as it came back with one non working light (which I didn't care about).
You may find a working mobo on ebay. Or you might inquire as to what sending it in for service would cost "out of pocket" and then weigh that against the cost of a modern low grade laptop now that would do most of what your M1710 does.
For me this happened during year 5, which I purchased the warranty for, and it paid for itself in this one incident.

 

I'd second a dead board.

Used M1710 boards are relatively inexpensive on eBay (less than $100 for the most part), though, as the GPUs die far more often than the board. You can use Precision M90 boards (closer to $50) too if you don't care for all the lights.

 

Ah the M90 parts too, great idea

 

Thanks for the advice, I'll try the motherboard.
The M90 is a lot cheaper! is the only difference the LED lights?

 

I have replaced the motherboard and it hasn't made any difference. The fault is exactly the same. Does anybody have any other ideas please? I am totally stuck now. Thanks

 

Sounds like one of the add on things is causing a short. I would remove ram, hdds etc untill it does something different. I had mine do something simular and used 1 stick of ram to boot. then all was ok again.