Hi
TH42PX70B - 10 blinks
Sub 5v S.O.S
main 3.3V S.O.S
DTV 9v S.O.S
Tuner Power S.O.S
PA board, H board, DG board
Beware: The blink errors are only a guide and you really need a manual and voltage checks are recommended to ascertain the actual fault.
Sorry I don't know about the TH42PZ28B - it's not one I recognise
Brian