Is this another GPU issue... or is the logic board a goner?

I’m wondering if my problem is similar to this one..

Getting three Beeps, Not RAM error

I recently inherited a MBP 15” Late 2011 from a friend due to it being unusable, and I was hoping to restore it to working condition. The issue I am facing here is that the MBP doesn’t start up and plays a beep code and the sleep indicator flashes. Watch the video below for the beep pattern/code.

RAM issue, right? Swapped out the RAM with known-good & known-compatible RAM, zilch… issue persists. Swapped drives because why not, that wasn’t the problem. Is this a GPU issue (ik these ones have the problematic discrete GPUs)? Is the logic board toast? If it’s the GPU issue

Things I’ve tried/noticed…

• SMC reset, issue persists
• PRAM (NVRAM) reset, issue still persists
• Beep code similar to the RAM beep code
• Sleep indicator light flashing
• Fans will spin
• MBP will get warm after 5 minutes of beeping/flashing
• Nothing on the display
• Battery indicator light displays battery percentage fine
• Battery will take a charge

@danj Alright so I tested the MBP with an external display and here is what happens.

The Mac appears to start up (plays the bong) and then (I missed this the first time around) I’m able to very faintly see the login profiles on the MBP’s internal screen (backlight issue, right?). However nothing shows up on the external screen until later on. I’m able to select a profile and log into it. Once I press enter to log into the user account the internal display goes completely black and the external display displays a white screen, nothing other then just a white screen. The MBP will get hot and after about 10 seconds later the MBP will shut down (fans stop and external screen goes black).

Hopefully that makes sense and provides some insight of what the problem could be.