How to diagnose the bootloader?

I have a breadboard Arduino 328 which was working a few months ago (June or July). When I connect it up now the led flashes but I can't remember what sketch is on it and my attempts to upload a new sketch have failed. I get the message

avrdude: stk500_recv(): programmer is not responding

I have a similar device that I put the bootloader on recently and I have no problem uploading sketches to it.

Is there any way to check the bootloader?


I think the easiest thing would be to just burn a fresh bootloader.

I should have said that I am avoiding burning the bootloader again for 2 reasons. Mainly because, due to the small size of the device, it's a PITA. But also because I am curious to figure out if something has gone wrong since June.

Obviously if the bootloader is at fault I will have to re-burn.


Are you sure it's not just a dodgy connection on the breadboard? I'd try pulling the components and wires one by one just to clear any crud.

It's all soldered. It just behaves like an Atmega on a breadboard with 8Mhz clock.

Can I download the hex code from the bootloader to my PC and then compare it with the hex code that should be there? If it's possible to download the hex code, how would I do that?


Apologies, @sirch. It was a badly soldered connection.


No worries, glad you solved it.