820-00165 no power corrosion on u6100

[elcapitan]

hello everyone im working on a water damage a1466 820-00165 with no power. It has green light on magsafe but no fan spin. during visual inspection i found heavy corrosion on u6100 (sst25vf064c)

1) can this chip prevent the board from booting up?
2) what is the purpose of this chip?

thanks,

 

[JohnB8812]

1. Yes it can, but it's likely not the chip but the traces or resistors near it.
2. That is the BIOS chip.

 

[dukefawks]

Very much a problem! Usually the traces are corroded and also the resistors that are in the data lines. Look up "termination resistors" in the schematic around U6100 and verify the traces and resistors are good.

 

[elcapitan]

i was able to fix this board by replacing that component. it was required for boot

 

[JohnB8812]

Did you transfer the ME Region??? If not this isn’t fixed!

 

[elcapitan]

i just took that chip from a donor board and its working perfectly. isn't the ME region stored in the bios chip?

 

[JohnB8812]

Yes! You cannot simply just put a new BIOS on and say good to go on the newer i5 and i7 machines!!! You need to read the old chip to transfer the ME OR set the new chip up with a clean ME. Duke can help you on that he's a boss at it. But NEVER just put a new BIOS on an send it off unless it's the old C2D machines.

 

[elcapitan]

thanks for your input John but u6100 is not the bios chip. Its a simple logic gate it provides the (cs) chip select for the bios. The device won't work without it. so its not necessary to transfer the ME region. Duke, please correct me if I'm wrong

https://assets.nexperia.com/docu.../data-sheet/74LVC1G99.pdf

 

[JohnB8812]

U6100 IS the BIOS chip. U6101 is the logic gate that does what you just said. If you replaced U6101, then you are ok. If you replaced U6100, then you are not ok.

 

[dukefawks]

You cannot just replace U6100 off another board like that! The ME region needs to be fixed and serial/model numbers should be fixed too.