A1502 820-3467-A no power

Hi,

I have an A1502 820-3467-A that has no green light.

PP3V42_G3H = 0.23V
SMC_BC_ACOK = 0.19V
PPBUS_G3H = 0V
PPDCIN_G3H = 19.5V

Couldn't find any short.

Can you help?
 

2informaticos

Administrator
Staff member
Could be D7010 problem; post its voltage.
Also post U7100 voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.
 
Hi,
D7010 has 6.69V

U7100:
PIN1= 0v , (but on R7186 CHGR_AGATE is 0V and CHGR_AGATE_DIV is 8V)
2 = 19V
3=4.7V
9=0v
12=0.2v
13=0.1v
14=0.1v
15=0v
17=0v
19=5.4v
20=5.4v
27=19v
 
Last edited:
U7090
1= 0.58v
2= 0.23v
3= 1v
4=0v
5= 0v
6= 17.5v
7= 0v
8= 17.5v

ohm to ground:
L7095:
1 = 1.3 ohm to ground
2 = 0.59 ohm to ground

C7090 = 5.5 Kohm

Diode:
L7095:
1 = 0.0018v
2=0.0011v

C7090 =0.397V
 

2informaticos

Administrator
Staff member
You have practically pure short at 3V42_G3H.
Is safe to inject voltage, no more than 4V.
Start with 1V, increase slowly if needed.
Don't forget to set PSU amp limit to max first.
 
It seams that what is shorted (it is what is geting hot) is the U5000. Does it make sense to you? Should i replace it?
I only have a 820-4924-A board. Can i use that SMC?
 
Last edited:
Hi, the short is gone from 3V42_G3H = 8.40 Kohm.
My problem is that i dont have that SMC to replace. Can you suggest any supplier in Europe?
 

2informaticos

Administrator
Staff member
I have never bought from EU.
Get scrap boards from China.
Make stock for several models, if you deal with Apple stuff.
 
Thanks. i'll do that, but i have none for this smc. Already bought a few, but it will take too long to arrive.

Thanks again.
 
Hi, The SMC has arrived and i already replaced, but steel no power and no fan spin (already have greenlight).

24 mA on PS

PPBUS_G3H = 12.56V
PPBUS_S5_HS_COMPUTING = 12.56 V
PPDCIN_G3H_ISOL = 19v
PP3V42_G3H = 3.4V
PP3V3_S5 = 3.3V
PP1V35_S3 = 0V

Waht should i check from here?
 
Last edited:

2informaticos

Administrator
Staff member
Do you get 3V3_SUS?

Post PM_DSW_PWRGD, PCH_DSWVRMEN, PM_PWRBTN_L, PM_RSMRST_L and SMC_ONOFF_L.
Trigger SMC_ONOFF_L (use R5115/16 pads) and check for drop pulse at PM_PWRBTN_L, at same time.
 
Hi,

3V3_SUS = 0v

PM_DSW_PWRGD =3.4v
PCH_DSWVRMEN =3.2v
PM_PWRBTN_L = 3.4v
PM_RSMRST_L = 0v
SMC_ONOFF_L = 3.4 v

I just realise that the Q5480 has burned up, and after removed the pads 3,4 and 5 are missing.

IMG attch
 

Attachments

Hi.

I Triggered SMC_ONOFF_L (use R5115/16 pads) and had a drop for pulse at PM_PWRBTN_L, at same time , but everything is the same
 
PM_SLP_SUS_L is missing.
I can't figure out where i can measure the 4 PCH RTC signsls. Can you, please, specify where to measure those?

PCH_CLK32K_RTCX1 = 0.36v
PCH_SRTCRST_L = 3.3v
RTC_RESET_L = 3.3v
PPVRTC_G3H= 3.3v

Note sure if this is what you want. Please advise.
 
Last edited:

2informaticos

Administrator
Staff member
Surely not, and we discussed so many times about RTC signals on the forum.
RTC block is clearly delimited inside PCH schematic.
Why did you check ONLY 2 signals, if there appear 4?
I waited to see DC signals, not clock; 2 RTC signals still missing.
 
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