820-2879-B Mid-2010 13" beeps.. sometimes

[Funkwarrior]

Hi,
I have this 820-2879-B that comes on macbook pro initially seems to freeze randomly. i thought was a RAM problem: changed with (2x8GB) DDR3 PC3-8500 1066MHz and started to work normally since, during a firmware upgrade, the macbook freeze. EFI Chip damaged: SOS Beeps. Changed Chip and now sometimes it beeps single one with 5sec pause, sometimes boot on system freezing after few seconds, sometimes -when i try to attempt to boot in recovery- it freeze on Wifi selection and the screen goes in semi-dim complete gray. I have also rebend two ethernet pins were shorted together. I hope in some help, and I hope is not GPU or CPU related.
Thanks!

 

[2informaticos]

MCP of this board is on its end already.
You can expect weird problems caused by it...

Try one RAM module at a time, each slot by separate.
Check resistance to ground at L6995; ohm mode, no charger, nor battery connected.
You should get more than 30K.

 

[Funkwarrior]

on a completely naked board with only 1 slot of original ram, i have :
Pin 1 and 2 2 ohm dropping to 0 ohm
1 and ground 24 ohm dropping to 14,7 ohm
2 and ground 24 ohm dropping to 14,7 ohm

 

[2informaticos]

Are these values for L6995???
That is almost short...

Check on diode mode (red probe to ground).

 

[Funkwarrior]

On diode mode,
Red to ground, black to pin 2: 0.330
Red to ground, black to pin 1: 0.330

 

[2informaticos]

That is normal value.
How did you get 2-14.7 ohm before???

You still need to get the ohm mode value on L6995.
Allow 10-20s before measuring, after power is removed...

 

[Funkwarrior]

now i have 8.1K on both pins, red probe on ground...

 

[2informaticos]

Bad MCP.
"You should get more than 30K."
This board is trash...

 

[Funkwarrior]

There is no further way to test if is it really the MCP?
A MCP rework is not advisable?

 

[JohnB8812]

The MCP is dead. Not worth fixing on a 9 year old board.

 

[Funkwarrior]

Ok, Topic closed. Not worth fixing it. Thanks all!