820-2879-b

[wirelessplanet]

Customer upgraded his computer and i purchased his old one. It boots up just fine but when i when to option boot to test asd or to reinstall os it will not work. just continues boot. it wont reset pram either. Ive tried with new keyboard and usb apple keyboard. neither work. ive tried to reset smc but that didn't solve.

 

[dukefawks]

Must use PC8500 RAM, at least one PC8500 RAM stick should be in there, the other one will not matter.

 

[wirelessplanet]

The ram is the ram that came with the computer. its 8500s ram. should i change it? just wondering why ram would mess with option boot.

 

[aprendiz]

EFI lock??

 

[wirelessplanet]

Not efi locked. just will not option boot or pram reset. if i put in a working hdd everything works out.

 

[dukefawks]

Swap BIOS from another board to rule that out. Also disconnect airport cable to rule that out.

 

[wirelessplanet]

replaced u6100 and disconnected airport cable. still no option boot or pram reset.

 

[dukefawks]

Disconnected everything and just use a USB keyboard? If not working remove R5701/02 to isolate U5701 from messing with USB.

 

[wirelessplanet]

okay so after removing r5701/02 usb keyboard pram reset works. i'm assuming i need to replace u5701?

 

[dukefawks]

That would seem like a plan.

 

[wirelessplanet]

all good now duke. thanks for the help. one quick question. should i put the old bios back on or can i leave the swapped on?

 

[dukefawks]

Does not really matter, only serial number is wrong now. No ME issues as is MCP platform.