Hey everyone - another update regarding this APC UPS BR1500G repair. And unsurprisingly, it continues to be a stubborn bastard!
I finally got in the items I needed to perform the flash of the micro - a FTDI UART to USB cable (datasheet attached), a replacement micro (it is a STMF102C8, datasheet attached) and I installed the STMCubeProgrammer software. I installed the drivers for the FTDI cable as well from their website. I also got a LQFP48 adapter board in case I had to remove the chip from circuit to flash it.
I read the ST application note 2606 to get info on the bootloader function for this chip. Here's how I set it up:
-Connected the VCC 3.3V (red) wire from the FTDI cable to VDD on micro
-Connected ground (black) wire from FTDI cable to VSS on micro
-tied BOOT0 (pin 44) on micro high (3.3V)
-tied BOOT1 (pin 20) on micro low (gnd)
-Connected the TXD (orange) wire from FTDI cable to PA9/USART1_TX (pin 30) on micro
-Connected the RXD (yellow) wire from FTDI calbe to PA10/USART1_RX (pin 31) on micro
-I selected 'UART' in STMCube software and checked to ensure serial configs matched (see photo attached).
Of course, once I was finished connecting everything, I tried to connect and an error message popped up saying 'Error activating device - check bootloader and serial configs and reset'. I double checked everything and powered cycled my setup and tried again - same result. I tried tying the NRST pin low to see if that would reset it, but that still gave me the same error. I tried connecting to the micro both in-circuit and out of circuit (note - I did verify that pin 27 is indeed shorted to VDD like I mentioned before!).
So now I've reached another brick wall again! I was hoping you guys could take a look at my set-up to make sure I'm not missing anything (I've attached photos as well). Any help would be greatly appreciated! Also, if the micro is read-protected by the manufacturer, would this explain the error message I am getting?
Thanks in advance as always!!