I recently finished recapping a TDS 644A. The startup self-check now passes, as does the signal path compensation. But when I try to perform a probe gain compensation cal operation, it fails. Interestingly, it only fails when my probe is in 10x mode. 1x mode appears to work. I'm using cheapie 100MHz probes from eBay.
Question: Is this some lingering issues with the scope, or is it just that my probes are too crappy? If the latter, is there any way to set the attenuation factor in the scope's software manually?