A1932 - 20V - 0.1 Amp - No DFU - 820-01521-A

[samstown]

Hello,

A1932. it was hanging from time to time and one day didn't boot anymore. I've tried several time to put it in DFU but no way.

USB-C chargeur connected, motherboard only, out from case



Thanks
Sam

 

[2informaticos]

What about G3S and SSD volatges?
Required SLPS2R and AWAKE voltages present?

 

[samstown]

P1V8G3S_EN on R084 switch from 0 to 1.8V every 3 secondes
P3V3G3S_EN on R8061 switch from 0 to 1.8V every 3 secondes
PP1V8_SSD on C8732 switch from 0 to 1.8V every 15 secondes, stay on 1,8 for 2 seconds

I've mentionned those above, it's not what you asking?
PP1V8_SLPS2R 1.8 V 1.8 V
PP1V2_AWAKE 1.2 V 1.2 V

 

[2informaticos]

"I've mentionned those above"
There are more around U7800.

Did you try to force it in DFU with external switch method?

 

[samstown]

Yes, I've tried manual DFU "A1932 & A2179 between pin 1/R8010 to pin 1/C7845, or other convenient 1V8_SLPS2R point" doesn't work.

PP1V1_SLPS2R Diode mode .255 - Voltage 1.1V
PP0V9_SLPDDR Voltage 0.9
PVDDCPUAWAKE_SW0 Voltage 0.76
PVDDCPUAWAKE_SW1 Voltage 0.76
PVDDCPUAWAKE_SW2 Voltage 0.97
PVDDCPUAWAKE_SW3 Voltage 0.97
PPVDDCPUSRAM_AWAKE Voltage 0.83
PP0V8SLPDDR_SW0 Voltage 0.83
PP0V82_SLPDDR Voltage 0.83
PP0V9_SSD Voltage 0.92

 

[2informaticos]

You may have problems with the DFU port connections, or T2.
Compare diode mode readings between both ports.

 

[samstown]

I've tried again to force DFU, no way. When using FORCE_DFU, I should only plug USB-C to USBC Mac with AC2, no casing, no special key to press, just the motherboard with USB-C (left port) cable to Mac runnning AC2

J3300 diode mode.

2 tpusbcpp20vxb OL
3 usbcxbcc1conn .693
6 usbcxbcc2conn .702
7 usbcxbr2dn1 OL
9 usbcxbr2dp1 OL
10 usbcxbr2dn2 OL
13 usbcxbd2rcrn1 OL
15 usbcxbd2rcrp1 OL
16 usbcxbusbtopp OL
18 usbcxbusbtopn OL
19 usbcxbsbu2 OL
22 usbcxbd2rcrn2 OL
23 usbcxbusbbotn OL
24 usbcxbd2rcrp2 OL
25 usbcxbusbbotp OL
28 usbcxbsbu1 OL
30 usbcxasbu2 OL
31 usbcxausbdbgbotn .315
33 usbcxausbdbgbotp .315
34 usbcxard2n OL
36 usbcxard2p OL
37 usbcxasbu1 OL
40 usbcxausbdbgtopp OL
41 usbcxar2dp2 OL
42 usbcxausbdbgtopn OL
43 usbcxar2dn2 OL
46 usbcxad2rcrn1 OL
47 usbcxad2rcrp2 OL
48 usbcxad2rcrn1 OL
49 usbcxad OL
52 usbcxacc1conn .705
53 usbcxacc2conn .710
56 tpusbcpp20vxa OL
59 60 pp20vusbcabvbus.146
57 58 pp20vusbcxbvbus .146

 

[2informaticos]

I see too many OL readings.
Did you really check all them with red probe on ground???

 

[samstown]

yes, and I've recheck again and again. They are really OL

 

[samstown]

So anything I can try ?

 

[2informaticos]

Clear the SoC ROM; machine must go directly to DFU.
Do NOT forget to make backup first.

 

[samstown]

That will not affect data on SSD?
You mean ROM backup, right ?

 

[2informaticos]

There is no information SSD related.
I talk about U4770.

 

[samstown]

Ok, I've cleaned U4770, went to DFU. Tried revive and failed.