Panasonic SA-HT900 ...

[Arfa Daily]

Has anybody got a proper paper service manual for this home cinema unit, or
access to a better Panasonic on-line copy for it, or a similar model for
their part of the world, than I have got here in the UK ? The tray timing is
completely screwed on the one I have on the bench. It looks like someone has
been 'at it' before me. The copy of the manual on the UK Panasonic service
website, is about two points to the left of useless in terms of the
reassembly / timing procedures. It is not a zoomable pdf file, but one of
those dreadful html things, where the photos and diagrams are all gifs with
a resolution of about 20 x 10 ! They appear on the screen the size of a
postage stamp - literally ... They are totally unreadable, and no use at
all. It's not as if this is a cheapo unit. How on earth do they expect
people to be able to fix the stuff, when this is the sort of level of
support that they're providing to their service network ?

Anyways, ranting aside, I just need to get a look at the tray re-assembly
diagrams and any notes, especially in regard of relative positionings, and
starting points for the cam gear, and the tray drive gear that runs off it.

TIA

Arfa

 

[D Yuniskis]

Arfa Daily wrote:

Anyways, ranting aside, I just need to get a look at the tray
re-assembly diagrams and any notes, especially in regard of relative
positionings, and starting points for the cam gear, and the tray drive
gear that runs off it.

Any obvious "timing holes" in the gear(s) that can give a clue?

 

[Meat Plow]

On Wed, 03 Nov 2010 17:19:14 +0000, Arfa Daily wrote:

Has anybody got a proper paper service manual for this home cinema unit,
or access to a better Panasonic on-line copy for it, or a similar model
for their part of the world, than I have got here in the UK ? The tray
timing is completely screwed on the one I have on the bench. It looks
like someone has been 'at it' before me. The copy of the manual on the
UK Panasonic service website, is about two points to the left of useless
in terms of the reassembly / timing procedures. It is not a zoomable pdf
file, but one of those dreadful html things, where the photos and
diagrams are all gifs with a resolution of about 20 x 10 ! They appear
on the screen the size of a postage stamp - literally ... They are
totally unreadable, and no use at all. It's not as if this is a cheapo
unit. How on earth do they expect people to be able to fix the stuff,
when this is the sort of level of support that they're providing to
their service network ?

Anyways, ranting aside, I just need to get a look at the tray
re-assembly diagrams and any notes, especially in regard of relative
positionings, and starting points for the cam gear, and the tray drive
gear that runs off it.

TIA

Arfa

Don't have any info. But having worked on a similar 5 disc rotary changer
unit I wanted to wish you good luck if you couldn't find suitable
technical literature.



--
Live Fast, Die Young and Leave a Pretty Corpse

 

[Trevor Wilson]

Arfa Daily wrote:

Has anybody got a proper paper service manual for this home cinema
unit, or access to a better Panasonic on-line copy for it, or a
similar model for their part of the world, than I have got here in
the UK ? The tray timing is completely screwed on the one I have on
the bench. It looks like someone has been 'at it' before me. The copy
of the manual on the UK Panasonic service website, is about two
points to the left of useless in terms of the reassembly / timing
procedures. It is not a zoomable pdf file, but one of those dreadful
html things, where the photos and diagrams are all gifs with a
resolution of about 20 x 10 ! They appear on the screen the size of a
postage stamp - literally ... They are totally unreadable, and no use
at all. It's not as if this is a cheapo unit. How on earth do they
expect people to be able to fix the stuff, when this is the sort of
level of support that they're providing to their service network ?
Anyways, ranting aside, I just need to get a look at the tray
re-assembly diagrams and any notes, especially in regard of relative
positionings, and starting points for the cam gear, and the tray
drive gear that runs off it.

**Send me an email. I may be able to assist.


--
Trevor Wilson
www.rageaudio.com.au

 

[Arfa Daily]

"Trevor Wilson" <trevor@rageaudio.com.au> wrote in message
news:8je1s2Fbg3U1@mid.individual.net...

Arfa Daily wrote:
Has anybody got a proper paper service manual for this home cinema
unit, or access to a better Panasonic on-line copy for it, or a
similar model for their part of the world, than I have got here in
the UK ? The tray timing is completely screwed on the one I have on
the bench. It looks like someone has been 'at it' before me. The copy
of the manual on the UK Panasonic service website, is about two
points to the left of useless in terms of the reassembly / timing
procedures. It is not a zoomable pdf file, but one of those dreadful
html things, where the photos and diagrams are all gifs with a
resolution of about 20 x 10 ! They appear on the screen the size of a
postage stamp - literally ... They are totally unreadable, and no use
at all. It's not as if this is a cheapo unit. How on earth do they
expect people to be able to fix the stuff, when this is the sort of
level of support that they're providing to their service network ?
Anyways, ranting aside, I just need to get a look at the tray
re-assembly diagrams and any notes, especially in regard of relative
positionings, and starting points for the cam gear, and the tray
drive gear that runs off it.

**Send me an email. I may be able to assist.


--
Trevor Wilson
www.rageaudio.com.au

Thanks Trev. See direct reply to the mail you sent me.

Arfa

 

[Arfa Daily]

"D Yuniskis" <not.going.to.be@seen.com> wrote in message
news:ias5nb$2dp$1@speranza.aioe.org...

Arfa Daily wrote:
Anyways, ranting aside, I just need to get a look at the tray re-assembly
diagrams and any notes, especially in regard of relative positionings,
and starting points for the cam gear, and the tray drive gear that runs
off it.

Any obvious "timing holes" in the gear(s) that can give a clue?

You would have thought so, wouldn't you ? The simple answer is "yes", there
are two holes in the main cam gear. Follow this though, with "no" - they
don't seem to give any clue as to where they should be set, and when ...
:-(

Actually, I now know what should be where, as Trevor in Oz has sent me a
Panasonic publication (that I didn't see or - maybe spot - on the Pan UK
website) that has a lot of general info on SA-HT series units, and down in
the depths of it, is a single sheet line drawing of what should be where and
when, together with some simple and straightforward notes. So tomorrow
morning, I will give it a go. Here's hoping ... !!

Arfa

 

[Arfa Daily]

"Meat Plow" <mhywatt@yahoo.com> wrote in message
newsan.2010.11.03.17.37.50@lmao.lol.lol...

On Wed, 03 Nov 2010 17:19:14 +0000, Arfa Daily wrote:

Has anybody got a proper paper service manual for this home cinema unit,
or access to a better Panasonic on-line copy for it, or a similar model
for their part of the world, than I have got here in the UK ? The tray
timing is completely screwed on the one I have on the bench. It looks
like someone has been 'at it' before me. The copy of the manual on the
UK Panasonic service website, is about two points to the left of useless
in terms of the reassembly / timing procedures. It is not a zoomable pdf
file, but one of those dreadful html things, where the photos and
diagrams are all gifs with a resolution of about 20 x 10 ! They appear
on the screen the size of a postage stamp - literally ... They are
totally unreadable, and no use at all. It's not as if this is a cheapo
unit. How on earth do they expect people to be able to fix the stuff,
when this is the sort of level of support that they're providing to
their service network ?

Anyways, ranting aside, I just need to get a look at the tray
re-assembly diagrams and any notes, especially in regard of relative
positionings, and starting points for the cam gear, and the tray drive
gear that runs off it.

TIA

Arfa

Don't have any info. But having worked on a similar 5 disc rotary changer
unit I wanted to wish you good luck if you couldn't find suitable
technical literature.

Think I've got what I need now, Meat - see my other reply in the thread.
Thanks for your luck wishes !

Arfa

 

[Arfa Daily]

Well, as it turned out, with the help of the info that Trev sent me, it was
actually staggeringly simple to realign. Of course, nothing's that
straightforward, is it ? After the tray was refitted and moving correctly
when hand cranked from underneath via the little gear that they kindly give
you to do just this, I put it back on power. The laser homed, the display
said "TRAY INIT", and that's as far as it went, before spitting the tray
out, coming to a stop, and the display changing to "TRAY OPEN". Nothing then
worked at all, until it was powered back off. Looking at the area of the
main PCB where the SMPS section is, there were several areas that were quite
badly scorched, and numerous small(ish) electrolytics were located in these
areas. A quick run over them with an ESR meter revealed four of them to be
virtually open, so I figured that we may have dirty rails here, that were
causing the micro to screw up during initialisation of the mechanics. Once
the board was out, it was easy to see why it was discoloured. Panasonic, in
a breathtakingly stupid bit of design work, have sited a whole bunch of sm
regulator devices on the underside of this SRBP board, using the copper as a
heatsink as well as an anchoring point. And then sited all the device
decoupling caps immediately above. I mean, who designs this stuff in the
first place, and then, what on earth is their manager thinking of, when he /
she signs it off as an approved design ?

Anyway, I replaced the caps and reassembled. Result ? Nothing, of course.
Exactly the same ... :-/

It then occurred to me that at no time had I ever seen the carousel
rotating, so I removed the tray again - confident now that I could put it
back in a flash - to have a look underneath at the drive motor and sensors.
This little bit of circuitry is connected back to the main PCB underneath
the deck, via a white flexiprint - the type with the blue strengtheners at
either end. When I looked a bit closer, at the board end, it was very
sharply bent at the inner edge of the strengthener. A quick ohms check
revealed that several of the ribbons were fractured at this point of bend. I
had a suitable length replacement for it in the junkbox, but it still didn't
quite end there. The original was one of those rather more rare types, where
the exposed connection 'fingers' at either end, were on opposite sides of
the ribbon, rather than both on the same side, as is more common, and was
the way my proposed replacement was. Fortunately, it was long enough to be
able to cut off the fingers at one end, and then scrape back on the opposite
side to reveal a new set. The strengthener was then glued back to the
ribbon, and the whole shebang refitted.

This time, everything cycled correctly at power up, and each of the five
disc positions was checked for the presence of a disc, before it all came to
rest showing "NO DISC" in the display. It then opened ok, closed ok, and
played a disc as it should.

Nice to get to the bottom of one that looked like it might be a non starter
at first

Arfa

 

[Trevor Wilson]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:5mxAo.7232$JW.3216@newsfe25.ams2...

Well, as it turned out, with the help of the info that Trev sent me, it
was actually staggeringly simple to realign. Of course, nothing's that
straightforward, is it ? After the tray was refitted and moving correctly
when hand cranked from underneath via the little gear that they kindly
give you to do just this, I put it back on power. The laser homed, the
display said "TRAY INIT", and that's as far as it went, before spitting
the tray out, coming to a stop, and the display changing to "TRAY OPEN".
Nothing then worked at all, until it was powered back off. Looking at the
area of the main PCB where the SMPS section is, there were several areas
that were quite badly scorched, and numerous small(ish) electrolytics were
located in these areas. A quick run over them with an ESR meter revealed
four of them to be virtually open,

**Good one Arfa. Your post reminded me of a job that came in a couple of
weeks ago. The client had left the item with a competitor, who made her pay
for a new output IC and a service manual (all at full retail, of course).
The company went belly-up before they could complete the repair, so they
handed the item back to my client. She brought it 'round and I did a few
tests on it. Everything pointed to a new output IC (why order a service
manual?), so I replaced it. No change. 7 small electros later and the thing
was performing nicely. Damned things. I don't even bother testing them
anymore. At 13c each, I just replace them.


--
Trevor Wilson
www.rageaudio.com.au

 

[Mark Zacharias]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:5mxAo.7232$JW.3216@newsfe25.ams2...

Well, as it turned out, with the help of the info that Trev sent me, it
was actually staggeringly simple to realign. Of course, nothing's that
straightforward, is it ? After the tray was refitted and moving correctly
when hand cranked from underneath via the little gear that they kindly
give you to do just this, I put it back on power. The laser homed, the
display said "TRAY INIT", and that's as far as it went, before spitting
the tray out, coming to a stop, and the display changing to "TRAY OPEN".
Nothing then worked at all, until it was powered back off. Looking at the
area of the main PCB where the SMPS section is, there were several areas
that were quite badly scorched, and numerous small(ish) electrolytics were
located in these areas. A quick run over them with an ESR meter revealed
four of them to be virtually open, so I figured that we may have dirty
rails here, that were causing the micro to screw up during initialisation
of the mechanics. Once the board was out, it was easy to see why it was
discoloured. Panasonic, in a breathtakingly stupid bit of design work,
have sited a whole bunch of sm regulator devices on the underside of this
SRBP board, using the copper as a heatsink as well as an anchoring point.
And then sited all the device decoupling caps immediately above. I mean,
who designs this stuff in the first place, and then, what on earth is
their manager thinking of, when he / she signs it off as an approved
design ?

Anyway, I replaced the caps and reassembled. Result ? Nothing, of course.
Exactly the same ... :-/

It then occurred to me that at no time had I ever seen the carousel
rotating, so I removed the tray again - confident now that I could put it
back in a flash - to have a look underneath at the drive motor and
sensors. This little bit of circuitry is connected back to the main PCB
underneath the deck, via a white flexiprint - the type with the blue
strengtheners at either end. When I looked a bit closer, at the board end,
it was very sharply bent at the inner edge of the strengthener. A quick
ohms check revealed that several of the ribbons were fractured at this
point of bend. I had a suitable length replacement for it in the junkbox,
but it still didn't quite end there. The original was one of those rather
more rare types, where the exposed connection 'fingers' at either end,
were on opposite sides of the ribbon, rather than both on the same side,
as is more common, and was the way my proposed replacement was.
Fortunately, it was long enough to be able to cut off the fingers at one
end, and then scrape back on the opposite side to reveal a new set. The
strengthener was then glued back to the ribbon, and the whole shebang
refitted.

This time, everything cycled correctly at power up, and each of the five
disc positions was checked for the presence of a disc, before it all came
to rest showing "NO DISC" in the display. It then opened ok, closed ok,
and played a disc as it should.

Nice to get to the bottom of one that looked like it might be a non
starter at first

Arfa

As Trevor said, "Good one, Arfa"

It does happen sometimes that the deeper we dig into something, we do
prevail, even if at first it looks like a non-starter.

Talk to you later.

Mark Z.