A1502 820-4924-A no power

hgoncalves

Active member
Hi,

I have an A1502 820-4924-A with no power.

I have green light and the the bench PSU pulls 80mA with the board only on the bench.

On PP3V42_G3H I only get 3.390V. Can it be that?
 

hgoncalves

Active member
Hi,

PPBUS_G3H = 12.58V
PP5V_S5 = 5V
PP5V_S4 = 0V
PP3V3_S5 = 1.2V
PP3V3_SUS = 0V
PP3V3SUS_EN=0V
PM_SLP_S5_L=0V
PM_SLP_SUS_L=0V
PPBUS_S4_X239 = 0V
 
Last edited:

2informaticos

Administrator
Staff member
"PP3V3_S5 = 1.2V"
Machine doesn't achieve S5 state even.
Check SMC_PM_G2_EN first.
Post U7501 basic voltages; pins 23, 22, 12, 13, 29, 21.
 

2informaticos

Administrator
Staff member
Looks like SMC problem; may need to change it.
Check diode mode to ground at 3V42_G3H; in both directions.
 

hgoncalves

Active member
Hi,

I've tried 2 new SMC but still no power. However, now I get this readings on U7501 pins:

12 = 3.4V
13 = 1.995V
21 = 3.4V
 

hgoncalves

Active member
HI,

Yes, now I have 3.3V on 3V3_S5/SUS

PP3V42_G3H = 3.4V
PP5V_S5 = 5V
PP5V_S4 = 0V
PP3V3_S4 = 0V

PPBUS_S4_X239 = 0V

The only thing that gets hot is U7100, but I think that it has nothing to do with it.
 
Last edited:

2informaticos

Administrator
Staff member
"ALL_SYS_PWRGD = 3.3V"
Do you mean steady voltage?
If yes, then must get steady voltage at L7520, L7430, L7630, and L7820/70 too.
In case of a pulse only, all mentioned coils should pulse too.

Try starting in SMC bypass mode.
 
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