old hitachi changes channel

[1goodmike]

I use this old 13" Hitachi TV to monitor video projects. It frequently resets itself to #2. Why is it doing this?

[torbjorn]

If the channel selector uses touch buttons, then a common cause for resetting to a specific channel is dirt around the touch buttons, causing leakage currents.
Another possibility is that flashovers within the CRT or on its surface causes trouble with the touch button circuitry. Make sure that the aquadag (graphite) coating of the CRT cone as well as the CRT's mounting frame are correctly grounded, all ground wires connected and routed according to the tv's service manual, any RC networks properly connected and in good order.
If the uncoated glass areas near the mounting frame, around the EHT connector and deflection coil etc are dirty, then cleaning those can also help.