I have received 200 loaded PCBs from my contract manufacturer, each with a ATtiny261V-10SU onboard. I am unable to connect via ISP. AVR Studio cant talk to the AVR. If I replace the AVR with one I have from stock, then it works just fine. I've check all the track wiring etc and it's all good (and therefore proved by inserting another AVR which works fine).
The design uses the onboard oscillator, so from factory I should be able to communicate ok. I had thought that maybe for some strange reason they had somehow been changed to external oscillator, so I injected both a 1MHz and a 100KHz clock signal and still nothing.
The codes on the bottom of the chip vary only slightly from the ones I have in stock, but are close enough that I don't suspect the chips are fakes, although that is still a possibility. I've emailed Atmel to try and get confirmation of serial numbers etc, but no response in 2 days. My supplier assures me the chips came from Digikey, so they shouldn't be fake anyway.
Is there anything else I should be trying that I can't think of? Replacing 200 AVR's is getting boring.
Cheers - Matt