Can I buy a power supply with the money in my Microsoft account?

No. The currency on your account can only be used for digital items.

That's the plan for the future but at the moment I don't have the money to buy a new power supply

I have the power supply in a area where no one should be able to get hurt by it. I all ready know how dangerous and stupid this is but it's just something I do to save money. it is currently plugged into a hot stick so I can power it off before I touch it.

It is exactly what I tried to do. But the website keep telling me that it cannot accomplish my demande, and that I have to contact support.

I did contact support through chatroom, and I got explain that they don'T have any power supply in stock, and it's not possible to repair my power supply, he then explain to me that i should buy a poser supply through amazone...

If they really did say they're out of stock then I'm afraid you will have to buy one on amazon.

If you're in the USA here's the link to buy an original Microsoft branded xbox one power brick:

https://www.amazon.com/Microsoft-Original-Supply-Adapter-Charger/dp/B00LGBA1RY

If it says it's from Microsoft as the seller (and says it's official) it will be the real deal. If for some reason you receive a 3rd party one and that's not what the Amazon page says where you bought it, you can use the A-to-Z guarantee from Amazon to get
your money back.

Is the red light on the power supply or the XBox 360 S console? If the red light is on the power supply it is a good assumption something might be wrong with the power supply. If replacing the power supply does not work I am sure you could sell the new
power supply to get your money back. It is certainly a cheaper option than buying a new 360.

Before you go crazy running the console around everywhere, see if your son has a friend with a similar console and power supply. Have them bring the power supply over and test the new power supply on your sons console. Chances are the console should still
power up if it was a power surge that only fried the "power brick". Inside that large black box on the power cord is a fuse that's there to protect the console from power surges. My power supply got fried when my house was hit by lightning and I was told
the console was toast. I spent $45.00 on a new Official Microsoft power supply after I had a friend bring theirs by and I was back in business!

If it's not the power brick that fried, I'd recommend sending it into Microsoft for repair as the Warranty would still be honored. If another shop that is not a certified Microsoft repair facility works on it, kiss that warranty goodbye!

Either way, the choice is yours honestly. If you'd rather not spend money on something that is under warranty, send it out to Microsoft for repair. If you'd rather not wait the 21 days for a free repair, see if you can test another power supply out on
your sons console. If it works, it might be a simple trip to the local gaming shop (Gamestop, Best Buy, etc) and pick up a new power supply.

Good luck!