(347) 552-2258 help@rossmanngroup.com

820-01700-05 Top ports 5V, Bottom Ports 0V. Replaced blown CD3217. Now 5V on each port. Still no power

C

CGid

Member
I have an 820-01700-05 that came in for now power. Upon checking the ports, the top 2 ports would get 5V ~200-300mA current draw. Bottom ports would give 0V.

After opening it up, we found the bottom ports' corresponding CD3217 ICs were blown. (PP3V3_G3H_RTC_X shorted on both with visible hole in the ICs)
I replaced both chips from a donor. Same location, same IC, same board number.

Now I get 5V on each port with around a ~250mA current draw.

PPBUS - 12.29V
PP3V3_G3H - 3.3V
PP1V8_SLPS2R - 1.8V

I attempted forcing the system to DFU via an external button. The device goes into DFU mode (1.8V measured on SOC_DFU_STATUS to confirm) , but is not detected by Apple Configurator.

Any thoughts on what to do next?
 
C

CGid

Member
Reflashed both ICs. I now get 20V on all ports but hover around a 62mA power draw. Only chip getting warm under thermal is T2.

I can still go into DFU mode and get 1.8V on STATUS to verify. However, I still can't see the system connected via Configurator.
 
2informaticos

2informaticos

Administrator
Staff member
Try different connection cable for DFU.
Better to use one previously tested with other machine; for DFU communication.
 
C

CGid

Member
The DFU cable I'm using I've used for at least four other Macs prior to this one. And it's still in quite good condition. I'll try it out though
 
C

CGid

Member
With a new and known good battery, the system boots to the OS. However, the system isn't charging. Just negotiates to 20V but only a 0.019 A draw. It's the same on all ports.
 
C

CGid

Member
Diode mode checked around it and found no shorts with the meter. Thinking it's a U7000 issue. I'm getting 20V to Q7030, but I'm not getting gate voltage on it. Will attempt replacing U7000.
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
Don't touch U7000!
You've said machine boots with battery.

U2800 may be your problem; even you didn't find bad readings on its power rails.
 
C

CGid

Member
Okay I will not touch U7000. I just figured that since Q7030 wasn't getting gate that it traces back to U7000. But I'll leave it.

So should I attempt replacing U2800?
 
C

CGid

Member
If it's anything of note. The system DOESN'T power on without a charged battery. So just via USB-C, no battery connected, I can not get it to boot.
 
You must log in or register to reply here.
Top