820-2327

[tlough75]

So I have a relic i would like to fix. It is an 820-2327. No light on magsafe but I do have PP3V42 but PPBUS is @ 12.28v. No signs of water damage and very minor tarnishing of a few probe points. I'm going to poke around some power rails a little more.

 

[tlough75]

I measured some stuff and found some interesting readings:

SMC_RESET_L: 3.42V
PP3V42_G3H: 3.42V
PPBUS_G3H: 12.28V
PM_PWRBTN_L: .480V
PM_RSMRST_L: .490V
PM_BATLOW_L .486V
SMC_ONOFF_L: 3.42V

Looks like PM_PWRBTN_L is low, which it send this to the MCP. Same with PM_PWRBTN_L.

 

[2informaticos]

Very old machine, MCP is on edge of its life; if not dead already.
Check ohm value to ground at 3V42 power rail.
A value lower than 30K usually points to bad MCP.

Do you get SMC_PM_G2_EN and 3V3_S5?
Post diode mode and voltage at SCL/SDA lines of battery bus.
Test disconnecting BIL connector.

 

[tlough75]

I should mention those values provided were taken with board out of the machine

 

[tlough75]

PP3V42_G3H Measures 5.1K ohms to ground at C6999.
0V on SMC_PM_G2_EN & 3V3_S5

SCL: .509/3.42v

SDA: .508/3.42v

 

[2informaticos]

You have one issue related with SMC, because of missing SMC_PM_G2_EN.
But I recommend you not to spend time on this board, because of such low value on C6999; MCP is dead 99%...

 

[tlough75]

Ok, thanks. I will call this one DOA.