I opened the box up and found the main board had a capacitor with a domed top - indicating it had failed.
OK, that worked a treat! My unit has been occasionally locking up for a year, and this week it upped its game to locking up every couple of minutes. Opened it up, immediately spotted the cap with a domed top, replaced it (had a selection of caps on hand previously purchased to support this unit), and so far it seems to be working perfectly! Thank you SOOO much!
This machine is not replaceable; we bought the current model from Channel Master but it was such an atrocious POS we had to send it back. Wouldn't work at all without a high-speed internet connection which I don't have and wouldn't be willing to use to run a DVR if I did. We have a couple of "converter boxes" from Walmart which work pretty well and are pretty reliable, but they are not user-friendly AT ALL, don't even put the name on a program you've recorded and a PITA to wind through commercials. I would have had to buy a couple more of them if this thing had been dead for good.
BTW, the rubber buttons on my remote crumbled, so I bought a remote for a Dish Network unit. I intended to steal the rubber button sheet out of the Dish unit for the Channel Master remote, but found out that the Dish Network remote actually controls the CM-7000PAL!