Potential graphics issue 2011 i7 imac

[TrynaBaDoctor]

Hi guys hope all you are well..

I have abit of an issue which I imagine is my graphics card.

So I turn on my Mac and am greeted with just a white line on the top of the screen going horizontally

After a number of attempts to start it I am then greeted with a whole white screen but a distorted apple logo.. Again after a number of attempts it finally boots normally.. But this happens every time I leave it for a few hours.. Is it possible this is a solder joint related issue which seems to warm up and connect on the graphics card and when cold doesn't start properly. Will baking help?

 

[mdgm]

Not sure what the cause of your issue is.

Baking can help if graphics card is failing. Other things people can try are undervolting the GPU which will affect performance but will stop it from getting as hot and hopefully complement the baking well to prolong the GPU's life a bit. Replacing the graphics card with a newer AMD Polaris card of a model used in newer Macs would enable decent performance running newer Mac OS through unsupported hacks. There is a long thread on replacing the graphics card. With the stock GPU running anything newer than High Sierra is painfully slow due to the non-metal GPU.

If you do open up the machine a new coin battery and installing a SSD (if still using a HDD) would be recommended as well.

Take a look at guides at e.g. iFixit and read the comments as well and take your time.

 

[TrynaBaDoctor]

Thank you for your advice... the issue I'm facing is quite odd so I might try to bake the GPU and see whether that boosts the computer to turn on first time all the time. Then probably upgrade or change the parts. Don't want spend any money and then find out other parts are faulty. Looking at the LEDs the first and second always light up suggesting the logic board is working properly. Would you agree?

 

[ezugaru]

Thank you for your advice... the issue I'm facing is quite odd so I might try to bake the GPU and see whether that boosts the computer to turn on first time all the time. Then probably upgrade or change the parts. Don't want spend any money and then find out other parts are faulty. Looking at the LEDs the first and second always light up suggesting the logic board is working properly. Would you agree?

Be careful, baking a Card has to be done in an oven You won't use for cooking, since some gases (tóxic) could be released with a chance of poisoning food.
You can use the flux + heatgun method too...