820-2915

[Anterweb]

Brought in for no power,

Board looks clean, apparently just stopped turning on.

NO green light on magsafe
( Using original working battery and Original 85w magsafe for testing )

3V42_G3H = 0v
PPbus_g3h = 0.568 and slowly drops.

I've checked all caps and resistors around u7000 and they all seem to measure correct.
(ive seen r7021 and r7022 go bad a few time before but they are good here)

any help appreciated.

 

[2informaticos]

Check diode mode to ground at L7030 and L6995.

Post U7000 basic voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.

 

[Anterweb]

L7030
Pin1 = 8.25m
Pin2 =10.30m (Slowly drops)
Pin3 = OL

L6995
Pin1= 12.23k
Pin2= 59.0k

U7000
1 =6.8mv
2=16.51v
3=3.93v
9=31.1mv
12=12.5mv
13=12.5mv
14=12.5mv
15=112.7mv
17=197.5mv
19=5.05v
20=5.05v
27=16.33v

 

[2informaticos]

First, make difference between diode mode and ohm scale.
Second, don't waste time checking both pins of a coil to ground.

Check R/D/U6990 and adjacent components.

 

[Anterweb]

You absolute legend!!
Ur like a logicboard Ninja!

D6990 was dead! replaced from donor board and machine is now working perfectly , thank you so much!

But please if I may Inf.. " First, make difference between diode mode and ohm scale." would you mind explaining what I did wrong here?

I took my diode mode to ground measurements ( red on ground ) in Ohms mode? I'm a little confused? I have an auto range meter is this causing me the problem when reading measurments?

Again, thank you so much for your help on this one, I would have never spotted that D6990!!!

 

[2informaticos]

When using autorange multimeter, select diode symbol on the screen.
You can't get K/M readings on diode scale...

 

[Anterweb]

I'm a Prat! thank you xx