Lapping advise please (RSX chip on PS3)

[Sumanji]

Hey,

Long story, but after a bit of experimenting I've found that the RSX chip on my PS3 is very concave, and does not make any contact at the centre. This is causing the console to overheat and make a lot of noise, so I want to try and lap it to make it flat.

Now I've read a few lapping guides, and have a fair idea of what to do. The problem is all of these guides had a mobile item being lapped - i.e. the CPU/heatsink is moved on sandpaper which is taped to some glass. The RSX chip however is soldered to the motherboard, so my only option is to rub something against it whilst it is in a fixed position.

What sort of object could I use to keep the sandpaper (and chip I supposed) perfectly flat? And how would I avoid bit of metal falling onto the motherboard?? Any advice appreciated!

Cheers,

Suman

[HKPolice]

Take a small piece of metal like an old Socket 7 heatsink, lap the base until it's a mirror. Cut a piece of sandpaper until it's the size of the base of the heatsink but with 2 opposite sides longer. Put heatsink on the sandpaper, fold the 2 longer ends upwards and you've got a nice sander for the chip. Don't worry about any metal particles, just use compressed air.

[Hypediss]

Can you take pix of the process/ when you lap your rsx? Would like to see if its worth it for me to do the same with my ps3 and all the best!

[Sumanji]

HKPolice, thank you that sounds like a cool idea :)

Hypediss, I'll poist back here with results!

Cheers,

Suman

[STEvil]

Take a small piece of metal like an old Socket 7 heatsink, lap the base until it's a mirror. Cut a piece of sandpaper until it's the size of the base of the heatsink but with 2 opposite sides longer. Put heatsink on the sandpaper, fold the 2 longer ends upwards and you've got a nice sander for the chip. Don't worry about any metal particles, just use compressed air.

That's a recipe for disaster..

That is almost guaranteed to get metal particles under anything that isnt sealed.


Put down tape around the chip you want to lap, this will help protect surrounding components from damage and keep metal particles from being deposited on the board. It is best if the tape is over the edge of the chip as well.

When you are done hold the board upside down and pull the tape off. Should keep the work area very clean.

[Sumanji]

Cool thanks STEvil, I was gonna do something along those lines anyways (no offence HK :D)

Cheers,

Suman

[Monkeywoman]

get a razer blade and then the sandpaper u wanna use. wrap the paper so it covers the sharp part. now tape around the RSX to prevent and dust or water from getting in contact ( regular painting tape is perfect) then using the taper of the sharp end of the blade, sand the IHS, use a little water to speed things up. This is how a guy on the forums lapped his G80, cant find the thread but he did it and it worked.

[Sumanji]

Won't the razor eventually cut though the sandpaper because of the pressure on it though?

Cheers,

Suman

[Monkeywoman]

no, not on the edge; the taper. you can dull you the edge just in case, but the taper is what u want to use.

EDIT: see here; http://www.xtremesystems.org/forums/showthread.php?t=163273&highlight=G80

[Sumanji]

Ahh ok thanks dude :) need to find a razor blade that is wide enough though, as the RSX chip is quite big...