A1342 820-2883-A no power

[hgoncalves]

Hi,

I have an A1342 820-2883-A with no power. I have green light, but no fan spin, and it only pulls 0.15A on bench PSU.

PP3V42_G3H = 3.382V
PPBUS_G3H = 12.59V
PP3V3_S5 = 3.310V
PP1V1R1V05_S5 = 1.0V
PP18V5_G3H = 19.9V (using 20V on PSU)
PP1V5_S3 = 0V
PP5V_S3 = 0V

I think L7560 is shorted (0.008 diode reading), but I'm not sure...

Can you help?

 

[2informaticos]

MCP core has low resistance to ground as normal.

Check resistance to ground at L6995 (ohm scale); should be higher than 30K.
Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L, at same time.

BTW, why do you like to test 60W machines with 20V?
Do you still expect to find a machine where VD0R will be triggered and you'll waste time for nothing on it?

 

[hgoncalves]

Well, I test all machines with 20V, because of lack of knowledge. I never know what the consumption of each machine is for sure, and I thought it was nothing very serious in macbooks. I will be more careful .

L6995 has 50K ohm to ground, and I have a drop pulse on PM_PWRBTN_L when trigering SMC_ONOFF_L

It seams that the problem is the power button...

TKS

 

[2informaticos]

PM_PWRBTN_L doesn't drop when pressing power button from keyboard?

"Well, I test all machines with 20V, because of lack of knowledge. I never know what the consumption of each machine is for sure"
Each charger has the output voltage marked on it, depending on its power.