Early 2013 15" A1398 Freezes on startup before showing login screen

[Vertx]

Hello!, i have MB pro 820-3332-A which started firstly panicking, after i had no image so U8900 was replaced and now there is image but machine freezes on startup and i can see keyboard lights up, caps lock light works, even sound but image is stil stuckl on apple logo. When closing lid backlight still on. Tried to clean ME with CH341A, haven't helped. And noticed after ASD machine boots fine, but works only for 20-30min until gets kernel panic and after restart same thing. Thank you for support!

 

[Vertx]

No Title

Got a log. Looks like GPU issue?, same U8900 causing problems?

 

[2informaticos]

Reflow GMUX.
If doesn't help, I suppose you have GPU issue...

 

[JohnB8812]

Could be GMUX could be VRAM. Any damage to the fan screw hole on the right side of the board?

 

[Vertx]

No Title

Sorry, might sound a bit stupid, but where exactly GMUX IC are located or named on schematics, can't find info about that one? Actually i did find, that screwhole is a little bit damaged.

 

[Alan.L]

i would try another U8900. you might have used a bad U8900.

this is the mux chip.