https://imgur.com/a/KJVGoku

Lately a ps4 showing lots of greyish noise, you can barely see it displaying the installed games and stuff… after asking someone he told me it could be the hdmi ic, or vga soo

After disassembling the ps4, some thermal pads on the graphic drams were removed… but i noticed that on the drmas, where the thermal pads were, there is some sort of greyish residue… i know this residue comming from thermal pads, but the thing is i couldnt remove it using alcohol and cloth… plus on some drams, where the thermal pads were, arround them there is some sort of shiny border in a square shape, like a liquidish stuff… it can be seen in the 1st pic, also couldnt remove using alcohol…

Does this means that the thermal pads became bad and need to be changed? Or could this be a sign that the graphics drams were getting too hot and possibly it is a sign of vga failure?