krishnakumar.r93
Member level 2
Hi all,
I'm new to the forum and would be glad if somebody could help me out ASAP.
I've made my own PCB design for SIM908, referring to the datasheet and have been using it in my various several projects for over a year and found no problem. The input to the board is 12V/2A. The output of the LM2576 to the VBAT is 3.98V.
According to SIM908, the PWRKEY has internal pull-up and is always high (3.98v).
Now, my problem is, recently i happened to finish up a board with a MCU and SIM908 (with the same hardware that i used before) and it worked perfectly for almost one week untill i happened to restart it as i was switching my place. After i powered it up again, nothing happened. The N/W led did not blink. The module is still good, but the voltage on the PWRKEY is 1.06v. I keep on receiving junk data from its TX/RX pins. The MCU is working perfect, only my SIM908 module isn't powering up.
What could possibly the problem? Somebody please help me out.
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THANKS IN ADVANCE.
I'm new to the forum and would be glad if somebody could help me out ASAP.
I've made my own PCB design for SIM908, referring to the datasheet and have been using it in my various several projects for over a year and found no problem. The input to the board is 12V/2A. The output of the LM2576 to the VBAT is 3.98V.
According to SIM908, the PWRKEY has internal pull-up and is always high (3.98v).
Now, my problem is, recently i happened to finish up a board with a MCU and SIM908 (with the same hardware that i used before) and it worked perfectly for almost one week untill i happened to restart it as i was switching my place. After i powered it up again, nothing happened. The N/W led did not blink. The module is still good, but the voltage on the PWRKEY is 1.06v. I keep on receiving junk data from its TX/RX pins. The MCU is working perfect, only my SIM908 module isn't powering up.
What could possibly the problem? Somebody please help me out.
- - - - - - - - - - - - - -
THANKS IN ADVANCE.