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U3900 is the T2 chip.
Is the machine detected in DFU mode?
Is the machine detected in DFU mode?
1- The battery is full sign does not appear on the screen, while the battery is plugged in, the current drawn decreases to 0.30, 0.60, 0.77, 0.85 and 0.05 amps, and the same thing is repeated all the time. I'm noticing the u3900 is getting a little hot. Is it normal for the u3900 to get hot at 0.05 amps? This device is in contact with liquid.
2-I haven't tried DFU mode because there is no battery charging message on the screen and it won't charge.
3-cb721 is not in place, does it prevent it from opening?
2-I haven't tried DFU mode because there is no battery charging message on the screen and it won't charge.
3-cb721 is not in place, does it prevent it from opening?
You should solder CB721 at the end, but doesn't prevent the board to boot.
If all AWAKE and SLPS2R voltages are present, machine should enter DFU; if T2 is good.
To complete DFU, SSD voltages must be there too.
If all AWAKE and SLPS2R voltages are present, machine should enter DFU; if T2 is good.
To complete DFU, SSD voltages must be there too.
I'm not sure if you tried DFU, or not yet...
The device does not draw a constant current. In the continuous restart mode, the current rises to 0.85 and then drops to 0.05. Doesn't that indicate that the device is not turned on? In the video, it is seen that there is a battery sign, no battery sign is displayed on the screen. I tried DFU mode and it did not work.
PPBUS_G3H is not stable?
AWAKE and SLPS2R voltages try to appear at least?
Try to understand, many times DFU fix boards not turning on.
T2 must turn on the board, when works properly.
Fixing T2 corrupted firmware, doesn't require the board to turn on; just need above mentioned voltages.
AWAKE and SLPS2R voltages try to appear at least?
Try to understand, many times DFU fix boards not turning on.
T2 must turn on the board, when works properly.
Fixing T2 corrupted firmware, doesn't require the board to turn on; just need above mentioned voltages.
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3V3_G3H_RTC stable voltage (L6960/91)?
Also check if AWAKE and SLPS2R voltages are present, or pulse at least.
Also check if AWAKE and SLPS2R voltages are present, or pulse at least.
Sorry, I meant L6960/61.
A lot of AWAKE and SLPS2R voltages on pages 75/76.
A lot of AWAKE and SLPS2R voltages on pages 75/76.
L7811 - PP0V82_SLPDDR = 0.8 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
L7813- PP1V8_SLPS2R = 1.8 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
L7814- PP1V1_SLPS2R = 1.1 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
L7816- PP0V9_SLPDDR = 0.9 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
In the video I sent you, the current was falling to 0, at that moment all voltages go out and then it comes back.
L7813- PP1V8_SLPS2R = 1.8 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
L7814- PP1V1_SLPS2R = 1.1 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
L7816- PP0V9_SLPDDR = 0.9 Voltage After 30 seconds, it drops to 0 voltage and returns to the same voltage.
In the video I sent you, the current was falling to 0, at that moment all voltages go out and then it comes back.
Is R7020 voltage stable?
Even 5V there (but stable) is enough for U7000 to generate PPBUS_G3H.
You may need to resolder, or change U7000.
BTW, check without battery connected, only charger plugged in.
Even 5V there (but stable) is enough for U7000 to generate PPBUS_G3H.
You may need to resolder, or change U7000.
BTW, check without battery connected, only charger plugged in.
current draw only when the charger is plugged in 0.06 amps
Motherboard is on blank board only charger is plugged in.
all voltages are stable without battery R7020 stable 20 volts
L7811,L7813,L7814,L7816 voltages are stable with no battery installed
(no battery) Q7065 pin 5 voltage is not stable 12.24 volts then drops to 0 volts . is this normal ?
F7000/1 12.24 Volt stable
Motherboard is on blank board only charger is plugged in.
all voltages are stable without battery R7020 stable 20 volts
L7811,L7813,L7814,L7816 voltages are stable with no battery installed
(no battery) Q7065 pin 5 voltage is not stable 12.24 volts then drops to 0 volts . is this normal ?
F7000/1 12.24 Volt stable
So you get stable SSD and SLPS2R voltages (no battery).
Check if AWAKE voltages are stable too.
If yes, then machine must appear in DFU.
Check if AWAKE voltages are stable too.
If yes, then machine must appear in DFU.
Take a look at page 75 & 76...
The device draws 0.22 amps at the first voltage, then drops to 0.05 amps. After about 1 minute, it drops to 0.0 amps and then returns to 0.05.
as if the device will turn on but there is a short circuit, so it won't turn on
PPVDDCPU_AWAKE = 0.7 voltage
PPVDDCPUSRAM_AWAKE = 0.8 Voltage
PP1V2_AWAKE = 1.1 Voltage
PP3V3_AWAKE =3.3 Voltage
as if the device will turn on but there is a short circuit, so it won't turn on
PPVDDCPU_AWAKE = 0.7 voltage
PPVDDCPUSRAM_AWAKE = 0.8 Voltage
PP1V2_AWAKE = 1.1 Voltage
PP3V3_AWAKE =3.3 Voltage
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