As I'm sure you have read, the most common problem for the then vertical line following the startup bong, is a crack in the solder joints at location L2, C1, or J1 (or combination thereof), unless it's smoking, which yours is not. Simply reflowing the solder joint may be all that is required, something anyone reasonably competent with a soldering iron should be capable. For an immediate fix that's all you may need, not a TV expert. However, given your limited skills and desire not to learn them, you should definitely keep looking for a local repairshop, as sooner or later something bigger Is going to die.

The problem may well turn out to be a bad C1 which does not show visible symptoms, but at least you will have eliminated the simplest steps as a cause. Also, pull apart the J1 connector and look for burning, as the connector or cable may need to be replaced. Replacing the cable is certainly an easy repair too. But once again, the C1 is the easiest part to replace on the 128K Mac. You do not an expert for that either, again any handy teenager with a soldering iron can replace that one quite easily. An ad placed in your local Craigslist will probably bring a few respectable offers.

One thing you should be capable of is adjusting your voltages to optimal settings, this alone will help stave off the inevitable as long as possible. This requires no special skills, just a screwdriver and multimeter, as Tom Lee's wonderfully helpful PDF has already informed you.