Originally Posted by
FABombjoy
Hence the use of the word "probably". Mk1 has a stress relieved power jack unlike the other incarnations, so it's considerably less likely.
Personal anecdotal experience:
Bad Genesis-1 power jacks: 0 out of probably 30 consoles
Bad Genesis-1 power supplies due to cable failure: 2 of at least 40
You have:
A dead RF modulator
A dead RF cable/adapter
A failing voltage regulator or two
A dead CXA1145
A failing TV tuner
Some other component failure
This is not a typical problem with a well known, simple to execute solution, especially if you lack the means to rule out your RF cable. If you just get static out of the headphone jack, that's probably not a good sign.