iMac 2008 not booting / screen issue

[Applethroughwindows]

I was recently given an iMac (2008 I think) from an old lady who said it wouldn’t Start up.
I thought I’d give it a go but I’m more of a pc guy so could do with some help.
It turns on to apple loading screen but stops halfway through & the screen goes dodgy like in the pics. Any idea what this might be?
**Note: I’m using

a windows keyboard**

Many thanks

 

[burka_tamas]

Typically graphic card issue sir

 

[Applethroughwindows]

Thanks, I figured as much. I did manage to reinstall iOS but that hasn’t fixed it.
a Video on YouTube suggests putting the GPU in the oven to remelt the solders that may have come loose. I wouldn’t mind trying a softer approach before putting anything in the oven!

 

[burka_tamas]

As on youtube you can try it in the oven
220-240 celsius 10-15 min long
I do it on many 2008 imac

 

[burka_tamas]

Reinstall would not funct until the the gpu is not ok

 

[Applethroughwindows]

I tried the oven method, & it worked.

Thanks for your replies.

 

[burka_tamas]

Once it works twice not at all be sure if u have correct thermal grease on the gpu check the temp always

 

[Applethroughwindows]

I've used a good quality Noctua thermal grease. Could you suggest a good free app for monitoring temps?

 

[burka_tamas]

Mac fancontrol
Or better Tg pro
Tg pro i can send u via email

 

[burka_tamas]

Or a hour later i can uload it anywhere then can post it

 

[Applethroughwindows]

Thank you! I'll give Mac fancontrol a try.

Would love TGpro but not too keen on sharing my email address here. Maybe a weTransfer or dropbox?

 

[burka_tamas]

Here is Hccps://mega.nz/file/w0MlUC6J#eR1hg6M_7d0b-cbpYaCc_eR_Uvkr5hu0J7GtzKG8P-s