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A1707 / 820-00928-A Won't boot

B

BillyE

Member
OK, I'm a newbie at this so I apologize in advance.
I have a A1707 15" Touch MacBook Pro that won't boot.... 99% of the time.
When I put the USB meter on it, I can see it got from 5.1v to 19.85v almost immediately and pull 0 amps.
I've pulled the board and done a lot of checks but still at a loss. After the first time I tried checking as much as I could I put it all back together and it booted up.
Booted a few times then died again.... So I took it out and tested again and no luck and put it back together and it booted.
But alas it died again no big suprise and remains that way. So out comes the board again (I'm getting good at that!) and here what I have tested so far.
UB300 5v at FB200:1 goes to 19.8 immediately
3.376v on CB308:1
1.791v on CB305:1
1.796v on CB306:1
1.112v on CB304:1
25.52v on QB300:1
21.58v on QB300:4
19.28v on CB214:1 or PPDCIN_G3H (not an apple charger but it is a 96W USB C PD charger)

UB400 19.8v basically immediately on FB201:1
3.376v CB408:1
1.788v CB405:1
1.802v CB406:1
1.119v CB404:1
25.54v QB400:1 and 21.74v QB400:4
19.27v on CB214:1 or PPDCIN_G3H

U3100 19.8v almost immediately on FB3000:1
3.376v C3108:1
1.796v C3105:1
1.802v C3106:1
1.11v C3104:1
25.48v on Q3100:1 and 21.62v on Q3100:4
19.78v on Q3100:8 or PPDCIN_G3H

U3200 19.8V immediately on F3001:1
3.373v on C3208:1
1.805v on C3205:1
1.781v on C3206:1
1.109v on C3204:1
25.51v on Q3200:1 and 21.57 on Q3200:4
19.78v on Q3200:8 or PPDCIN_G3H

5v on U6903:10 - PM_EN-P3V3_G3H
3.416v on L6900:2 - PP3V3_G3H
1.221v C5013:1 PP1V2_G3H_SMC_VDDC
3v C5167:1 - PP3V0_G3H_AVREF_SMC
3.414v R3042:1 SMBUS_SMC_4_G3H_SCL
3.414c R3041:1 SMBUS_SMC_4_G3H_SDA
5.083v C7016:1 TBA_AUX_DET
3.415 R7090:2 SMC_RST_L
19.51v D6903:3 8V6/20V
19.78v U700:10 P_IN
19.51v U7000:5 MPM_PBUS

5.085v on TBA_VDDA and TBA_VDDP - Seems like I got VDDA but VDDP was gone so I unplug/plugged in the charger and both there? Can't remember for sure
Measured 5.1 ohms on R7075 still in circuit
5.084v on PM_EN_P3V3_G3H
3.388v on HPWR_EN_L
3.05v on SMC_WAKE_L
3.415v L5001 and showed continuity across it

That was a check list I found online, I checked a bunch of other PPBUS's and all seemed good.

As I moved from CD3215 I moved the USB charger to the associated input.

Again sorry for too much info but I am a hack at best but trying to learn.

thanks
 
2informaticos

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

Don't bother with USB-C areas, if all ports switch to 20V.

Be aware, this board requires 87W charger to start without battery connected.
A bad battery can also impede to start, using 45/61W charger.
Confirm the charger are you using.
 
B

BillyE

Member
Yes, it says it's a 96W charger, I also replaced the battery thinking that might be it, but no avail.
Yeah I checked the USB-C areas because it seemed to most likely based on what I found on the internet. But since it wasn't looping it didn't seem likely.
 
B

BillyE

Member
I think so? I googled resting both but neither seemed to do anything. To to be honest maybe I should try again. I know at one point I reassembled and forgot the power button ribbon under the audio jack? So maybe I tried resetting with that disconnected? Who knows I've tried a bunch of stuff.
 
ipetro

ipetro

Member
if you take the board out of the macbook and connect it to the table, does it boot up via USB meter? with a 96 watt charger, it should work without a battery!
 
B

BillyE

Member
I put the board back in and tried to reset the SMC no good, it won't boot at all so the resetting the PRAM didn't work either.
Yes if I have just the board out it does boot the USB meter, goes from 5v to 19.8 almost immediately.
 
ipetro

ipetro

Member
What is the USB meter reading? (20 В / 0,800 А)? 20 volts power supply and in terms of amperes it is clear what is happening
 
B

BillyE

Member
With the battery only disconnected it just loops at 5 volts? If I disconnect the battery and the Battery management cable then it boots to 19.88 volts. If I try my volt meter on the new battery I get 0v? The old battery is at about 2.2 volts? I guess they are both just discharged?
 
B

BillyE

Member
Not sure I understand your previous comment "Каковы показания USB-метра? (20 В / 0,800 А)?"
 
ipetro

ipetro

Member
0 volts seems to be blocked battery. 2.2 volts is working but you don't need to connect battery for testing.
 
ipetro

ipetro

Member
How do you determine if the board is loading if it is on the table and only connected to a USB meter?
 
B

BillyE

Member
Sorry I thought you meant the USB meter booting. When I plug it in it takes a hot second for it to boot up to show the power going thru it. I don't know if the board is booting. I warned you I was a newbie! lol
 
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