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Technics AV Control Receiver SA-DX950 keeps having to be reset. Repairman says

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Last response: in Home Audio
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July 9, 2011 1:48:03 PM

I trtied to have local repairman repair unit but he says he cannot get the manual or parts to repar due to parts/manual being discontinued. Is there somewhere else I can send to have repaired.
July 9, 2011 3:48:18 PM

hah!

if one repair person told me no, i would go to the next one and the next one.
some repair people really barely ever pick up a soldering gun.
they do the diagnosis and buy the complete board.
and it isnt all that hard to not blame them.. because a lot of the manufacturers have setup the system that way.

you need somebody with real experience.
and that means know how and why the pieces do what they do.
that way they can take a good look at it and throw it back together, possibly making improvements along the way.
but
i suppose it is truth to say the person would be more of an electrical engineer rather than an electrical repair person.
seems like for the last 20 years the electronics industry has been trying to force electronics repair people to buy the complete board.
and they really try too.
sometimes the pieces are heavy-duty and completely hard to find.
and sometimes it is because the replacement part can be two or three times the size of the old part.
gotta go with what you know.
meaning you have to monitor voltages and learn what is too much.
that means breaking some things to learn.
and when all you have is a 4405-393 to get you moving along.. it doesnt make any sense.
that number is typically a 'house number' .. meaning if technics put the number there.. only technics knows what it means.

it boils down to having to take the entire thing apart and test each piece to see how it works.
then buy new pieces and test them out to get something similar.. all while monitoring the voltages to keep them up to par.
and then you have to worry about capacity numbers being accurate (both new and old/used).
you also have to worry about esr values being accurate (both new and old/used).
you have to learn resistors and how their characteristics work (both new and old/used).

to really be somebody in electronics nowadays.. you have to know how each piece works and why.
and you have to do it with the depth of knowledge that falls short of knowing the names of the chemicals they put into the pieces to make it do that.
yes..
good diagnostic skills helps too.
but
if you dont know how one thing works, you dont know how the whole array of things are 'supposed' to work.
when you do..
you can do your diagnostics faster, with full potential to provide upgrades.

i have been thinking about learning how capacitors work to start myself out.
but
all i can think of is to apply some voltage, then connect a light bulb and watch the pattern change.
then try to come up with some kind of pattern with the different values.
maybe if i do that long enough i will start to see a difference between one brand name of said properties, and a different brand name of the same properties.. to actually hunt down a lie.

all i can think of is to use the light bulb and maybe some oscillating DC voltage or current.
and if i ever get a single piece figured out.. then i can start to look at the different ways an array of the pieces work.
maybe i could start there, if only i could depend on the values written on the piece to be accurate.
i would probably be stuck with building my own designs using the same number of pieces in the array.
but
maybe i could remove some pieces and watch the change to see if i can make out with some useful data.

maybe the electrical repair person was a 'newb'
or
maybe they were confused about something.
or
maybe they lied to you and tried to get you to buy a new receiver.

i would be willing to drive about an hour (or an hour and a half) one way, to get my electronics repaired.
really gotta dig into it to get upgrades out of the electronics repair person?
m
0
l
!