MBP early-2011 2.0 i7 - totally dead, no boot any method.

MBP early-2011 Sandy Beach series 2.0ghz i7, 4gb, 500gb.

Hi, after going up to 10.9.4 a graphics issue began with iPhoto. Eventually the screen went patterned and needed a forced reset. After that it will not boot at all, just the grey-screen after the apple logo / chime.

Safe-mode loads the progress bar, but then goes to the same grey-screen.

Recovery-partition does not work, just goes to a solid blue-screen.

Booting from a Snow Leopard dual-layer install DVD does not work, just grey-screen.

Booting from a Lion single-layer install DVD does not work, just grey-screen.

Clearing the PRAM / VRAM, even 3 times at once, does not have any effect.

Resetting SMC has no effect.

I have tried both sticks of RAM, independently, in both slots. This has no effect.

I swapped in a HDD from a 2008 MBP running Mavs 10.9.3. This gives the same grey-screen, though this HDD is from an MBP that also stopped working under Mavs and may be corrupted.

The only step left to take is to try a new store-bought blank HDD and see if that will boot from an OS X install DVD.

If that doesn't work, I have read that a failed HDD-cable can cause this problem - does anyone think this is worth trying?

Does anyone think it is worth trying to remove the battery and force a complete reset of the hardware?

If the HDD or cable is not the fault then I assume it is the graphics-card that has somehow malfunctioned under Mavs and it will need to go into the Apple store.

Thanks for any advice, James