Pioneer VSX-D409 Receiver - Shuts off by itself

[[email protected]]

Hi everyone,

I am a newbie at repair, although I have a background in basic
electronics. I am working with a Pioneer VSX-D409 receiver that
doesn't seem to want to stay on. When it is on for any length of time
- even seconds, there is a click, and it shuts itself off.

1. There is no visible sign of component damage (burnt resistors, I
believe there are two fuses, good continuity, no blown up caps etc).
Board is clean.

2. The voltages comming to the transformer from the AC outlet appear
good, as do the ones leaving it.

I am not really sure where to start with this! If anyone has any
ideas, they would be much appreciated!

Thanks,

[email protected]

 

[Sofie]

Burningmarshmellow:
Two places to start..... the audio power output stage (output & drivers),
emitter resistors, coupling electrolytics, etc....
and the power supply, rectifier diodes, zeners, electrolytics, regulator
chips, low ohm resistors, etc.
For more troubleshooting tips, repair procedures, component testing methods,
etc you can go to the website for this newsgroup at:
http://www.repairfaq.org/
There, with some searching you will find lots of useful information.

 

[[email protected]]

I have an update:

Against all good judgement, I started the receiver, over and over
again, looking for the source of the seemingly over-current
protection.

Now F701 and C705 are blown. Really blown. Infact, I am pretty sure
that I will not be able to smell anything except burnt capacitor for a
couple days.

Someone has GOTTA have a better idea than this?

Thanks!

[email protected]

 

[Sofie]

Burningmarshmellow:
Yes... a better idea was given to you 3 hours earlier in my reply post to
you.
The text of that previous reply is below:

"Burningmarshmellow:
Two places to start..... the audio power output stage (output & drivers),
emitter resistors, coupling electrolytics, etc....
and the power supply, rectifier diodes, zeners, electrolytics, regulator
chips, low ohm resistors, etc.
For more troubleshooting tips, repair procedures, component testing methods,
etc you can go to the website for this newsgroup at:
http://www.repairfaq.org/
There, with some searching you will find lots of useful information."

It is never, never a good idea to quickly cycle power on and off or keep
applying power to a circuit that is shutting down. As you found out, the
symptoms get worse and more parts will fail.... and the resultant repair
will now be much more involved and more expensive.
Live and learn.....

I have one question for you..... why didn't you at least make an effort to
perform some tests as outlined in my reply and go to the repairfaq website
for troubleshooting and repair information instead of cycling power and
looking for smoke? ? ?

 

[[email protected]]

Hi Sofie,

Thank you for the reply. I am new to using newsgroups, and for some
reason didn't see that there was a reply.

I agree, cycling the power on and off wasn't the best of ideas. I
didn't expect the results that I got, but.. hey, I'm new to this!Like
you said, live and learn. With a little luck, only the cap is shot,
and the rest is okay. Looks to me, from what I can see, and what I
have read, it is a "filter cap".

I have checked the continuity of most of what I can see so far, and
there doesn't appear to be anything that is open, and the caps, less
the exploded one, all show ok as far as a resistance check.

In regards to the process you mentioned, do you suggest that checking
for continuity is the best way to being? Sorry if this is a stupid
question, I am very green. Will read through that FAQ right away.

Thanks again,

[email protected]