Does anyone know why the iMac won't boot?

[flodschi22]

The Story behind:
I saw this iMac for Sale on a platform and the Buyer says since a few days it won't start anymore. So it's cheap but I don't know how much would it be to fix this problem?
I haven't bought it yet because I wanna hear your words about it, would be nice!
Thanks

Specs:
iMac (27Zoll,Mid 2011)
Processor 3,1 GHz Intel Core i5
Memory 16GB 1333Mhz DDR3
Graphic AMD Radeon HD 6970M 1024MB
Start Volume (replaced 2 years ago): Samsung 500Gb SSD

Some more photos here, thats all I know and have about this iMac:

Video

 

[Fishrrman]

2011 iMacs have a tendency for an internal GPU failure.
Unless you're skilled at repair, and have money to waste, I'd STAY AWAY from this one.

 

[flodschi22]

2011 iMacs have a tendency for an internal GPU failure.
Unless you're skilled at repair, and have money to waste, I'd STAY AWAY from this one.

Okay thanks you saved me! 😍