Pioneer VSX-D503S repaired

[Kevin]

This is for Archive purposes. Neighbor gave me this AV Receiver with no
output. I had repaired a VSX-453 for my son 3 years ago and had purchased
the manual. The manual covers VSX-403, VSX-453 & VSX-463S. The unit given
to me used the same 5 channel output amplifier as my sons so the repair was
easier with a good manual. The receiver would power on but no audio, the
relay wouldn't click coming out of Standby. I found the right front channel
had bad (shorted output transistors and many other parts. This repair took
me about 6 hours.

These are the bad parts:

Q4 = 2SA1302
Q3 = 2SC3281
Q512 = 2SC4793
Q514 = 2SA1837
Q508 = 2SC2705
Q506 = 2SA1145
R534 = .33 Ohm 5 Watt Dual Resistor
R575 & R576 = 2.2K 1/8 Watt
R612, R614, R616 & R618 = 4.7 Ohm 1/4 Watt Fusible
R526, R528, R530 & R532 = 100 Ohm 1/4 Watt Fusible
D522, D524 = 1N4752A 33 Volt Zener 1 Watt
D526 = 1SS252 Used a 1N4148
D548 = MTZJ20 Used a 20 Volt Zener

 

[Mark D. Zacharias]

No way it should have had all those parts bad. Somebody must have tin-foiled
the fuse, or used a 30 amp car fuse or the like.
Good job fixing it, though I have to question if it was worth the effort.


Mark Z.

 

[Kevin]

A couple of the transistors were questionable and cheap, so it was worth the
few extra dollars to change them. The resistors were all open, some burnt.
The guy that owned it was a "hacker". I thought he outgrown it (he is in his
early
20's), but he probably "opened" it and because of his interest in
electronics, dropped something inside accidently !!. It's just another
"goodie" for one of my family members. Funny how i'll put in the time
fixing an audio / video piece but won't touch a computer.

 

[iamnathanhudson]

i have my front right channel going bad.....it distorts and barely gets any
signal.....but then last night it worked fine........now today it won't
work......i know it is the front right because i hooked my left speaker to
it and it isn't the speaker it is the output........is there anyway you
could take a picture or something to show me some of the things to look
out....i have it here sitting open so knowing the more important things to
look at and kind of where they are would help greatly. thanks
-Nate

 

[Mark D. Zacharias]

The first thing I would look for in this situation is bad solder
connections, at the speaker terminals, and maybe at the output IC and
protection relay. Also the relay could be cutting out, though this is less
common on receivers of this type.
Most Pioneer models of recent (the last 15 years or so) have little to no
direct access to the main board - even just to look at it will require a
major disassembly.


Mark Z.