macbook pro a1278 ...820-3115b..taking 0.300 milli amps

[NIKHIL@1997]

hi..i have a macbook pro a1278 ...820-3115b..taking 0.300 milli amps...when i check the board
there is

=PPVTT_S0_DDR_LDO

missing this voltage ..then i check the enable signal...

=DDRVTT_EN

this enable also missing

 

[NIKHIL@1997]

another intresting thing is ..this board sometime working...also display is coming..that time this voltage also active..

 

[2informaticos]

All the other voltages present, when te board is stuck?
Post the VCORE voltage after 10s.
PLT_RESET_L comes high?

 

[NIKHIL@1997]

now the board takes only 0.340milli amps...in this condition VCORE voltage is zero
PLT_RESET_L also 0

 

[NIKHIL@1997]

plz give a replay

 

[2informaticos]

Apart of CPU, do you get voltage on other big coils?
Check ALL_SYS_PWRGD.

 

[NIKHIL@1997]

ys...get voltages on all big coils...cpu coil volages missing
ALL_SYS_PWRGD get 3.3v

 

[NIKHIL@1997]

what next...

 

[2informaticos]

Check R7402/03.
Also check all SPI Bus Series Termination resistors and their traces.
If all good, try known good BIOS.

 

[NIKHIL@1997]

R7402 shows 150 k
R7403 shows 182 k
SPI Bus Series Termination resistors and their traces are ok(showing correct value)
also try 2 bios...still same

 

[2informaticos]

Check U7400 basic voltages; pins 19, 29, 46, 47.
Do you note any drop pulse at 1 & 48?

 

[NIKHIL@1997]

pins 19:-5 v
pin 29:- 5v
pin 46 :- 5v
pin 47 :- 3.3v
R7402 gets 0.60v
R7403 gets 0.49 v(ic side)

 

[NIKHIL@1997]

also i change core ic.....still same

 

[2informaticos]

No voltage at all at L7510/20?
Looks like CPU power supply is running...