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820-3115 No green light -short on PPDCIN_G3H_CHGR

G

goldminer76

Member
Hi I have an 820-3115 that had no water damage. It had no GREEN LIGHT

Power Rails were:
PP3v42_G3H 0.0V - NO SHORT
PPBUS_G3H 0.0V - NO SHORT

Found SHORT on:
PPDCIN_G3H_CHGR @ C7031 + C7030 (22UF) -top of cap read: 22 1E24
I have a donor board and replaced those caps and got rid of the SHORT
The DONOR CAPS read on top: 22 1E2N (ORIGINALS WERE 22 1E24)
Does that make a difference?

I replaced ISL6529 -U7000 with new chip. I'm now reading and I think I might have needed to replace 2 or 3 other components at the same time before giving it power?

TESTED VOLTAGE AFTER AND STILL:

PP3v42_G3H 0.0V - NO SHORT
PPBUS_G3H 0.0V - NO SHORT
PPDCIN_G3H_CHGR 0.2V - NO SHORT

Any advice going forward is much appreciated.
 
2informaticos

2informaticos

Administrator
Staff member
I didn't see the reason for changing U7000 yet.

You may have an input leakage issue, as you don't get any voltage on the board.
Check first if F6905 is good and has voltage.
 
G

goldminer76

Member
F6905 has continuity between PIN 1 & Pin 2

Voltage with 85w charger connected

PIN 1 = 0.0V
PIN 2 = 0.0V

DIODE MODE

PIN1 = .OL
PIN 2= .OL
 
G

goldminer76

Member
Well I just realized I was getting Trolled by my power strip. It had disabled only one plug. My charger.
When I connected it with "POWER" this time I saw a GREEN LIGHT but also smoke around R6990
With freeze spray R6990 (PIN 1 =PPDCIN_G3H/ PIN 2=P18V5_DCIN_CONN_R)
looks hot right away.

Took off R6990 on the Pads I get:
Voltage: PIN 1 = 16.77V PIN2= -0.05V
DIODE MODE: PIN1= 1.97 PIN2= 0.0

I just changed the DC in board as I think it was part of the culprit too and it was. Facepalm.
If I replace R6990 I'm worried that I'll "Smoke Check" something again.
Should I be concerned with D6990?
 
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2informaticos

2informaticos

Administrator
Staff member
Really strange to get short in pin 2/R6990.
In such case, (at least) lower side of D6990 is also shorted.
You must replace both R/D6990.
Do not apply power yet; you will still have short on PPVIN_G3H_P3V42G3H.
Remove C6990 and check if short went off.
If still present, change U6990.
After that check again for short at C6990/99; before applying power on the board.
 
G

goldminer76

Member
Replaced R/D6990
Removed C6990 (Diode Mode on PIN1= 0.377)
Diode mode on D6990 PIN 1=0.45 - PIN 2= 1.98 PIN 3= 0.34

Not too sure if there was still a short so just replaced U6990

Added power no green light (no smoke either)

Now R6990 PIN 1=16.7 PIN 2= 16.7

U6990 VOLTAGE

PIN 4= 16.45v
PIN 3= 15v
PIN 2= 3.8v
PIN 1=1.2v

PIN 10= 3.2v
PIN 9= 3.4v (PP3V42_G3H).
PIN 8= 3.4v
PIN 7= 16.45v
PIN 6= 3.4v

D6690 Voltage
PIN 1= 0.399v (is this the problem?) PPBUS_G3H_R
PIN 2 = 16.7v
PIN 3= 16.45v


PPBUS_G3H = 0.277v @ F7040
Diode Mode 0.477 @ F7040

Thx again. this ones kicking my butt
 
2informaticos

2informaticos

Administrator
Staff member
Post basic voltages for U7000; pins 1, 2, 3, 9, 12, 13, 15, 19, 20, 27.
Be sure to have correct ohm resistance between pins 17/18 and 27/28.
 
G

goldminer76

Member
U7000

1=6.7v
2=2.34v
3=3.9v
4=l.4v
5=0.005v
6=3.4v
7=0.0v
8=0.026v
9=0.002v
10=3.4v
11=3.4v
12=3.4v
13=3.4v
15=0.068v
16=1.19v
17=5.57v
18=5.5v
19=2.34v
20=2.33v
21=0.0v
22=GND
23=2.9v
24=2.2v
25=4.8v
27=2.8v
28=3.0v

ohm resistance 17/18= 3.7
27/28 resistance started at 3.7 but kept going up and up and up past 7.0
 
G

goldminer76

Member
Replaced R7005

Now U7000 PIN 2= 16.7

Don't see the second Resistor. Can it come off of any PIN of D7005?

Stiil no green light.

Bravo for finding everything that's wrong though.
 
2informaticos

2informaticos

Administrator
Staff member
"second Resistor"
Nobody talks about such resistor.

You now have correct DCIN at U7000; didn't check PPBUS_G3H voltage?
 
G

goldminer76

Member
oh Sorry "At least one of R/D7005 is bad (open), maybe both." I thought meant there were two resistors to look at. What did you mean by both? I know that D7005 now has 16.7 on all PINS. Going to the shop now and will check PPBUS_G3H. Thank you
 
G

goldminer76

Member
Thank you.
PPBUS_G3H is 12.7v @ F7040 @ R6905
PP3V42_G3H is 3.4v @ C6999

I'm new at where to test so sorry if there is no structure as to where I'm testing.
No Green light still.
 
2informaticos

2informaticos

Administrator
Staff member
Board doesn't turn on?

For green light issue, post U6900 voltages.
Check continuity from pin 5 of U6900 to central pin of Magsafe (DCIN board).
 
G

goldminer76

Member
Reading have changed on U7000

1=6.7v Now= 0.003v
2=2.34v Now=16.7v (obviously)
3=3.9v
4=l.4v Now=3.4v
5=0.005v Now=1.18v
6=3.4v
7=0.0v Now=0.85v
8=0.026v Now=2.0v
9=0.002v Now=

Oh wow I see U7000 heating up real fast. Going to replace again and see if that's the issue.
 
G

goldminer76

Member
Just so I can wrap my head around this relationship between U7000 and U6900. U7000 needs to work to Enable U6900 to give out PP3v42_G3H_REG or is it the other way around? I think the first scenario. I know it's probably more complicated than that so No need to go into the whole one wire explanation I know I can look it up and watch your guys videos. Thx
 
G

goldminer76

Member
U6900 voltage:

PIN 1 = 0.049v
PIN 2 = GND
PIN 3 = 0.0v
PIN 4 = -0.042v
PIN 5 = -0.003v

Question? What does it mean when you get a (-) negative voltage. Is it just that those pins 4 and 5 aren't power rails?

Just in case here is:
U6990 voltage:
Pin 1 = 1.2v
Pin 2= 3.8v
Pin 3=15.5v
Pin 4= 16.52
Pin 5= 0.0v
Pin 6= 0.010v
Pin 7= 16.54v
Pin 8 = 3.88v
Pin 9 = 0.010v
Pin 10 = 0.0v

Continuity good Pin 5 of U6900 to Central Pin DC IN board

U7000 does heat up rather quickly under freeze spray like in 2 seconds. Just FYI

(edited because I took readings from U6990 instead of U6900)
 
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2informaticos

2informaticos

Administrator
Staff member
You cannot have green light, if no 3V42_G3H present and also SMC_BC_ACOK.

I don't understand how do you work.
"PPBUS_G3H is 12.7v @ F7040 @ R6905
P3V42_G3H is 3.4v @ C6999"
What did you do, to lose these voltages???
 
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