Hi all,

Just on the chance that someone has seen this kind of thing before - a
friend's Yamaha RX-V520 5.1 receiver won't power up by the switch on the
front or the remote.

A quick look inside shows everything looking OK - fuses are also fine.

Lacking a service manual I'm not sure where to go from there. Has
anyone seen this problem before?

Thanks for any help,

Matthew.

"Matthew Kirkcaldie" wrote in message
...
Hi all,

Just on the chance that someone has seen this kind of thing before - a
friend's Yamaha RX-V520 5.1 receiver won't power up by the switch on the
front or the remote.

A quick look inside shows everything looking OK - fuses are also fine.

Lacking a service manual I'm not sure where to go from there. Has
anyone seen this problem before?

Thanks for any help,

Matthew.

Any activity at all ? Standby LED ? Powers for a moment and then shuts down
immediately ? Yammy AV amps are very complex, and not for the faint hearted,
but if it is *totally* dead rather than not coming or staying out of
standby, you might stand a better chance with it.

Arfa

Does the unit have a small standy power transformer?. If so, isolate
and check for an open primary.
Jango

In article ,
"Arfa Daily" wrote:

Any activity at all ? Standby LED ? Powers for a moment and then shuts down
immediately ? Yammy AV amps are very complex, and not for the faint hearted,
but if it is *totally* dead rather than not coming or staying out of
standby, you might stand a better chance with it.

Arfa

Totally dead, no LED, no nothing. As Jango suggested I'll look for a
small standby transformer - I was thinking it must be something like
that to power the logic for the controls on the front while it's off.

Thanks Arfa, give my regards to Terry - I might come and see you about a
tasty motor sometime.

Cheers,

MK.

"Matthew Kirkcaldie" wrote in message
...
In article ,
"Arfa Daily" wrote:

Any activity at all ? Standby LED ? Powers for a moment and then shuts
down
immediately ? Yammy AV amps are very complex, and not for the faint
hearted,
but if it is *totally* dead rather than not coming or staying out of
standby, you might stand a better chance with it.

Arfa

Totally dead, no LED, no nothing. As Jango suggested I'll look for a
small standby transformer - I was thinking it must be something like
that to power the logic for the controls on the front while it's off.

Thanks Arfa, give my regards to Terry - I might come and see you about a
tasty motor sometime.

Cheers,

MK.

You're welcome, and your kind regards have been passed to Terry ...( ! )
Jango's suggestion is a good one, and exactly what I would have said. He too
is an experienced engineer. If the worst comes to the worst, I have access
to Yammy service info. Mail me off-group if you get to the point of needing
it, and I'll see what I can do for you.

Arfa

Thanks for the endorsement Arfa , what are you busy with these
days?.
Well, Matthew, how's the progress on the RX-V520 going?. I try my best
to post final results on a successfully completed job here so people
may refer to it later.
Jango

"jango2" wrote in message
ups.com...
Thanks for the endorsement Arfa , what are you busy with these
days?.
Well, Matthew, how's the progress on the RX-V520 going?. I try my best
to post final results on a successfully completed job here so people
may refer to it later.
Jango


Hi Jango

Same old same old. Still pitting my wits against recalcitrant hifi's, DVDs,
DVDRs, PVRs, group amps and the plethora of other nonsense and rubbish that
the poor old public have inflicted on them as the latest "must have". Guess
you're probably about the same. We are also working on an updated version of
the three-changer video, and perhaps a couple of others like the Pan
5-changer. Watch this space, as they say ...

Arfa

In article . com,
"jango2" wrote:

Well, Matthew, how's the progress on the RX-V520 going?. I try my best
to post final results on a successfully completed job here so people
may refer to it later.

Bit hectic here, probably have to wait until next weekend! But I will
definitely post my outcome.

Cheers, MK.

In article . com,
"jango2" wrote:

Does the unit have a small standy power transformer?. If so, isolate
and check for an open primary.
Jango

In one of the more awesome pieces of long-distance diagnosis I have
known, it turns out the small standby power transformer has an open
primary!

Now - my problem is to find out what to replace it with. It runs on
240VAC (Australian mains) and the markings on the side are

XW608 AO
TAM M 0118

It's only got one primary and one secondary as far as I can see.

I have a schematic for the RX-V420, which is a slightly less powerful
version with the same features (this one is RX-V520), and the
transformer is on the schematic. It's component T161, listed as an
"XW608" for the Australian model in the parts list on the right. Seems
like the same components are used in this part of both models.

The schematic shows "AC 12.8" as the voltage measurement across the
secondary.

I am a bit naive in these things but I am assuming

(a) that 12.8 is VRMS, and
(b) that a 240V AC transformer with a 12.8V RMS output, of similar
physical size, would be a good replacement (I can't see a power rating
and I assume it would be small given that it probably only runs the
standby switch, IR receiver and a relay).

How critical is the voltage likely to be? It looks like there is some
kind of regulatory circuitry downstream. I can supply that part of the
schematic if it would help.

Thank you SO MUCH for your incredible suggestion.

Cheers,

Matthew.

Ah well, didn't work. It was a classic case of finding what I set out
to look for - I had been using the continuity beeper on my multimeter to
see if the primary and secondary were open or not - turns out the
primary WAS OK but its resistance was slightly higher than my meter will
beep for. So that wasn't the fault after all. I've given up and will
pass it back to my mate in the hope he can take it to someone who
actually knows what he/she is doing.

Thanks to everyone who helped.

Cheers,

Matthew.