820-00165 PPBUS_G3H short

MarcinRdm

Member
The board is clean, However, I have a short to ground on:
PPBUS_G3H,0.9-0.4 ohm
PPBUS_S5_HS_COMPUTING_ISNS 0.9-0.4 ohm
PPBUS_S5_HS_OTHER_ISNS 0.9-0.4 ohm

Is the CPU dead ? What to do ?
 

2informaticos

Administrator
Staff member
PPBUS, is PPBUS; no need to test in different points.
Check if any big coils has the same resistance to ground; usually CPU ones.
 

2informaticos

Administrator
Staff member
Then is safe to inject voltage.
Set lab PSU amp limit to max first.
Start injecting 1V and slowly go up, if needed.
 

MarcinRdm

Member
The short was on c7314.
Now:
PPBUS_G3H 0.4V

U7100 voltages:
1- 0
2- 15.6
3- 0
9- 0.02
12- 3.4
13- 3.4
15- 0.04
17- 0
19- 5
20- 5
27- 0
 

MarcinRdm

Member
I'm changing U7100.
PPBUS_G3H 1.2 V
U7100 voltages:
1- 0
2- 7
3- 4.3
9- 0.03
12- 3.4
13- 3.4
15- 0.03
17- 8.5
18- 8.5
19- 5
20- 5
27- 16
 

MarcinRdm

Member
I replaced U7100 and R/D7105
1- 0
2- 5.4
3- 4.3
4- 3.3
5- 1
9- 0.03
12- 3.4
13- 3.4
15- 0.04
17- 8.6
18- 8.6
19- 5
20- 5
27- 16
 

MarcinRdm

Member
PPDCIN_G3H 16.2
PPDCIN_G3H_ISOL 16.2

But diode mode F7140
pin 1 - 0,125
pin 2 - 0,460
Is it just a burnt fuse ?
 
Last edited:

2informaticos

Administrator
Staff member
F7140 is burnt.
But you still have a problem with R/C/D7105, or U7100.
You cannot lost 10.8V over R/D7105; at least R7105 is damaged.
 

MarcinRdm

Member
I replaced the D7105 and it starts but will not power on with battery power.
C7116:
pin 1 - 1,4 v
pin 2 - 8,6 v
R7151 and R7152 pin1/2 - 8.6 v
I tried a new battery and a pram reset.
 
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