So due to the ongoing chip shortage and supply chain issues I've only been able to source "used" or "refurbished" parts for some of the components that I use. I received some ATMEGA64M1's recently and was planning on using them to replace the same part on boards that I rebuild. I'm able to successfully read the flash and EEPROM data from the original chips via ISP but I can't do anything with these refurbished pieces. I keep getting an error in Atmel/Microchip Studio saying that it's failed to enter the programming mode. It also will not read the device signatures. I've tried 2 of these chips so far and have had the same results.
After doing some reading I realize that the lock bits or fuses may be an issue with them since they've been previously programmed. However, I'm not 100% sure if that's the case or if the chips are just dead/bad to begin with. Is there any way to confirm if they're just locked or completely dead via Atmel Studio?
If they were readily available I'd purchase these new if I could. Anyway, I'm a novice when it comes to this stuff and I've read about parallel programming but I don't think I will have the time and patience to even begin such a project.
Thanks in advance!