A few things to try.
Try random accessing either ch3 or 4 with a remote.
Go into the menus & be sure the tuners are set to normal off the
air stations.
Try auto program, if it has it, with VCR on.
The YYYYY is strange !
Modding it is too much trouble. Its a hot chassis so not so simple.
There are tons of free sets with a nice jack pack out there.
73 Zeno
LFOD !