I am working on a hl7812 modem and one of the devices stopped working without any reason. I noticed that the modem is not responding to any at commands, there is no sign that it is alive there.
I dont think there is a hardware or power supply problem.
The only thing inconsistency:
VGPIO is always high, though, GPIO6 is low
So I was using gpio6 as a low power mode indicator.
i didnt have a chance to observe uart pins with an oscilloscope, but if I had anything coming out of uart0, I think I should have seen gibberish on the console screen at least. However, I observed that the CTS pin was high too.
NOR boot spl: Uncompressing u-boot image ... OK (141488 => 254824 55%)
Transferring control to u-boot ...
U-Boot 2012.10 (Dec 15 2021 - 12:47:40) ALT1250_03_02_00_12_15041_UB
Board: ALT1250 Ver: 0.32-SB-E0 (PMP CPU Speed 120 MHz)
Platform id 9D9-989
DRAM: 3 MiB
Now running in RAM - U-Boot at: 902a4000
Boot mode 2
Flash Manufacturer/Device ID is: 0x20bb18
Enable QUAD mode
Flash: 16 MiB
*** Warning - Merge environment, using default environment
map import OK
USB CTRL has been successfully initialized!
In: usbtty
Out: usbtty
Err: usbtty
Configuring Flash Write Protection (offset 0x192e00)
new_ce_val = 0x3a0001f0
Rst info: shutdown : power on, no reset
Hit any key to stop autoboot: 0
Version: 2.0
Nothing to upgrade...
hbsb ok. 194 ms
## Starting
NOR boot spl: Uncompressing u-boot image ... OK (141488 => 254824 55%)
Transferring control to u-boot ...
U-Boot 2012.10 (Dec 15 2021 - 12:47:40) ALT1250_03_02_00_12_15041_UB
Board: ALT1250 Ver: 0.32-SB-E0 (PMP CPU Speed 120 MHz)
Platform id 9D9-989
DRAM: 3 MiB
Now running in RAM - U-Boot at: 902a4000
Boot mode 2
Flash Manufacturer/Device ID is: 0x20bb18
Enable QUAD mode
Flash: 16 MiB
*** Warning - Merge environment, using default environment
map import OK
USB CTRL has been successfully initialized!
In: usbtty
Out: usbtty
Err: usbtty
Configuring Flash Write Protection (offset 0x192e00)
new_ce_val = 0x3a0001f0
Rst info: power on, no reset
Hit any key to stop autoboot: 1
NOR boot spl: Uncompressing u-boot image ... OK (141488 => 254824 55%)
Transferring control to u-boot ...
U-Boot 2012.10 (Dec 15 2021 - 12:47:40) ALT1250_03_02_00_12_15041_UB
Board: ALT1250 Ver: 0.32-SB-E0 (PMP CPU Speed 120 MHz)
Platform id 9D9-989
DRAM: 3 MiB
Now running in RAM - U-Boot at: 902a4000
Boot mode 2
Flash Manufacturer/Device ID is: 0x20bb18
Enable QUAD mode
Flash: 16 MiB
*** Warning - Merge environment, using default environment
map import OK
USB CTRL has been successfully initialized!
In: usbtty
Out: usbtty
Err: usbtty
Configuring Flash Write Protection (offset 0x192e00)
new_ce_val = 0x3a0001f0
Rst info: shutdown : power on, no reset
Hit any key to stop autoboot: 0
Version: 2.0
Nothing to upgrade...
hbsb ok. 194 ms
## Starting
one of the healthy board’s uart0 output: yes u’re right, in out is serial,
But im %100 sure i dont have circuit issue with usb comport on the bad device. it shouldve been visible when I plugged in an usb .
Even after we re burned the sw to the modem, why didnt we have serial is default? Normally, serial uart1 was always defualt on good devices.
NOR boot spl: Uncompressing u-boot image ... OK (141488 => 254824 55%)
Transferring control to u-boot ...
U-Boot 2012.10 (Dec 15 2021 - 12:47:40) ALT1250_03_02_00_12_15041_UB
Board: ALT1250 Ver: 0.32-SB-E0 (PMP CPU Speed 120 MHz)
Platform id 9D9-989
DRAM: 3 MiB
Now running in RAM - U-Boot at: 902a4000
Boot mode 2
Flash Manufacturer/Device ID is: 0x20bb18
Enable QUAD mode
Flash: 16 MiB
*** Warning - Merge environment, using default environment
map import OK
In: serial
Out: serial
Err: serial
Configuring Flash Write Protection (offset 0x192e00)
new_ce_val = 0x3a00f8e0
Rst info: shutdown : power on, no reset
Hit any key to stop autoboot: 0
Version: 2.0
Nothing to upgrade...
hbsb ok. 194 ms
## Starting