if all inputs are showing lots of static interference, then there might be a problem with the input board.. or maybe it is the amplifier circuit.
when the am or fm radio is giving lots of static interference.. it might be a weak signal, so if you know the signal is local.. then the tuner portion of the radio might be bad.
maybe it is the tuner itself, maybe it is the connection between the tuner and the rest of the amplifier.
the electronics repair people can tell you which or what it is.
you might have a bad piece that is causing the rest of the circuit to collapse.
the entire circuit is old and needs to be fully replaced.
i suppose the real question is, if it can be 'patched' .. how long will the rest of the circuit last now that it has been under stress.
if the entire circuit needs replaced, is it worth it?
old electronics can be difficult when something goes wrong.
the problem might be repaired, but something else might die from old age in the early future.
that is why the electronics repair person needs to know the 'pieces' they are working with.
known to be failure resistant certainly helps.. but not always the case when the piece has been stressed too much for too long.
i think it is kinda neat that many of the electronics of today have a safety feature to prevent the hardware from being used when there is a problem.
it can prevent the hardware from over-stressing itself and save the parts inside before they are over taxed.
an example, the car's engine dies and wont start.
the person keeps trying to start the engine, taxing the starter.
the starter might get hotter than it is supposed to from all of the electricity running through it.
and when the car engine is fixed, the next thing that dies might be the starter.
a good question with electronics is.. are the pieces on the circuit board designed to fail all at the same time or is there a lot of time between one failure to the next?
because to an electronics repair person, it means replacing the entire circuit board with a new pre-assembled one (or do it manually piece by piece).
otherwise, the fix doesnt have to cost much money or time.
not saying replacing the entire circuit board with a pre-assembled one is time consuming, because connecting some wire harnesses is usually easy and quick.
it is much more expensive to have the circuit board ordered, compared to replacing a couple individual pieces.
all in all, it depends on the electronics repair person.
if they dont want to use their electronic testing/diagnostic equipment.. to save the precious (and expensive) equipment from being used on projects they feel is not worth 'wasting gas' or 'wasting the life of their diagnostic equipment'
then yes, asking them to use the diagnostic equipment to find the problem and 'patch' it is maybe the same price as the pre-assembled circuit board.
experience can go a long way sometimes.
usually when there is experience with the make and model of the electronics hardware.. the repair person knows exactly where to first look for a problem.
they can remove the usual problem and test the pieces for functionality without using the precious diagnostic equipment.
the worst case scenario is arguing with the electronics repair person.. because usually the arguement ends with a higher price to be paid for the repair.
and that price is usually reflecting the use of more time spent on the project and breaking out the expensive diagnostic equipment.
it might be that the diagnostic equipment is ment for a different group of products.. meaning the resistance of your electronics is much different than what is intended to be used with the diagnostic tool.
sure, the electronics repair person might have two seperate diagnostic tools.. one for high resistance and one for low resistance, but if the resistance is in the middle.. using either one of the diagnostic tools raises a question as to if by using it are you over-taxing it and shortening its lifespan?
kinda like asking for a ride 2 miles away
asking for a ride that is 200 miles away
for 2 miles, you are probably only paying for the gasoline.
for 200 miles, you are probably paying for gasoline and tires, and maybe some cost towards new piston rings (or the price of a new electronic sensor).
you probably shouldnt be paying for the full price of a tire, because you arent using the full tread on the tire.
but there are 4 tires and if you add up the full price and deduct a small percentage for the wear of the tire.. there is hope that the fee's could keep the business from using their own money to patch the tire when they run over a nail or screw.
that is how businesses operate huh.. lol
and it might be better to ask a friend and do them a favor in return.
if you can teach the electronics repair person how to do something, i would simply ask if they know how to do it and if they want to learn by saying 'i can teach you how to ____ if it helps with my repair bill.'
a person who is handy at a lot of things (except electronics) could get a lot repaired (or possibly upgraded).
i would be cautious if you make money doing what you are teaching, because you have experience you might get the job.
if you teach the electronics repair person how to do it, they might teach their buddies and that buddy might have payed you to do it.
trading information can get a lot done.
we live in a productive world that depends on getting something done.
however, some people depend on a person paying for something to be done.
not that i agree, because anybody should be able to learn how to do it themselves if the process doesnt require a master's degree to accomplish perfection.
your results might not be the best, but if there is an improvement to be had.. it should be for the better.
paying for someone else to do something for you should have a good reason.
either you simply cant figure out how to do it yourself, or maybe you dont have the extra time to do it.. these are the usual reasons.
sometimes people dont do it because the weather is too hot/too cold.. or they dont want to clutter their garage with extra tools.
maybe the person (or place) they are getting a loan from wont fund the project unless a professional does it.
because sometimes when a project fails, the person gets angry and tries a different project (or needs more money to fix the failed project).
that isnt paying the money back for starters.
and some parents want the result to be a guarantee, and arent willing to hand over the money unless there is some kind of guarantee of happiness.
could be discriminating for a jack of all trades.
not everybody accomplishes something with a degree or certificate from college.
an apprentice would be one example.
with all of that said..
you first need to ask yourself 'how much money am i willing to spend on the repair?'
then find an electronics repair shop (or person) to compare prices.
people dont usually go to college to share the information.. if they did, they would probably become a teacher or write a book.