Toshiba TV29C90 problem; Image fades to black...

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
message news:pridnQ4PwfsC8ufVnZ2dnUVZ_h7inZ2d@comcast.com
My money is on the receiver signal path beyond the
decoder. There are lots of places for just one channel
to get lost.

Which is what's happening. It just isn't happening in the
original digital stream.
Click to expand...
Agreed.

Since most home audio gear has DACs that are either 2-channel, or a number
of channel pairs, it is highly probable that *any* signal in the digital
domain has both channels present.

An exception would be something like a DSP that is running code to implement
a balance control or channel level control.
 
"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:_7ednRdYQaCszefVnZ2dnUVZ_oDinZ2d@comcast.com...
The sending device might be coding the datastream as a mono feed...

There is no such thing, in consumer products, as a mono SPDIF feed.
Indeed,
one of the design errors of the Compact Disc is the failure to include a
mono mode that would double disk capacity for pre-stereo recordings.
Click to expand...
Right, I was thinking AES3.

or the receiving device is failing to decode the datastream as a stereo
feed.

Which makes no sense, as it's hard-wired to divvy up the signal into left
and right.
Click to expand...
Right, I was thinking AES3.
 
"Richard Crowley" <rcrowley@xp7rt.net> wrote in message
news:_rqdnZGFkdqcEufVnZ2dnUVZ_rHinZ2d@posted.pcez...
"Arfa Daily" wrote ...
"Chronic Philharmonic" wrote ...
The sending device might be coding the datastream as a mono feed, or the
receiving device is failing to decode the datastream as a stereo feed.
It might be something as simple as a configuration problem (one of the
devices is set to 'mono'). To diagnose a fault, use a protocol analyzer,
or a process of elimination by substituting components until you get
something that works.

Even if it were, that would not result in the loss of one physical
channel's reproduction from the amp. What you would have is both left and
right channels combined into one single mono channel, which would then be
identically coded onto both left and right channels, within the single
SP/dif data stream. So you would get two channels physically reproduced,
but each containing the same mono audio.

But only a fantasy academic discussion as there is no monaural mode
defined for SPDIF.
Click to expand...
Probably true enough, but the occasional flight into academic fantasy does
no harm, and keeps the old grey cells firing ... d;~}

Arfa
 
<mustafacatflap@googlemail.com> wrote in message
news:5f44486f-3566-44a6-838a-9ffba28b2b53@p25g2000hsf.googlegroups.com...
On 14 Jul, 14:12, Adrian C <em...@here.invalid> wrote:
mustafacatf...@googlemail.com wrote:
Hi all, hope someone can help.

My next door neighbour, who is 98 years old, is rather deaf, and we
would like to get her a pair of TV headphones to make everyone's life
a little easier - her's esspecially!

Just wondering about this. If she has a hearing aid wouldn't it be a
better plan to use an inductive loop coupler? That hearing aid would
have been designed for her particular problem and linking the TV sound
directly to it would also benefit by the same sound tailoring.

--
Adrian C

Yes, of course you're absolutely right. However, she won't wear her
hearing aids, she says thy're too uncomfortable, and in any case, she
only has one although her hearing is universally damaged. I've just
been talking to the headphone manufacturers and they were surprised
neither the tv or the video had jack or phone outlets, but if they
have, I can't see them.

Thanks for your response

Mustafa
Click to expand...
If he has hearing aids the (best) solution is a wireless communication system
(FM). I personally have this and would recommend it.

A wireless communication FM system consists of a transmitter, which picks up
voices near the transmitter or sounds from a TV speaker and sends it via radio
waves, wirelessly, directly to the tiny radio (FM) receiver, which is connected
onto the personal hearing instrument (hearing aids). No connections to the TV
are involved. Range is about 100 feet and being FM you can hear the TV or voices
through walls.

They are expensive but work, available through an audiologist and matched to the
specific hearing aids manufacturer.

Good also, are available from TV stores and uses an invisible light beam
transmission to a set of headphones. Works good but you need an audio output
jack on the TV. If anyone is "handy" a jack can be purchased at Radio Shack and
added to the TV. Requires some soldering.

Next would be a device like ListenUp, which is advertised on TV and ARP
magazine. No idea how good but I assume they would be OK. A device you wear
with ear buds cost $20 with shipping. Note: I have no relationship with this
company nor do I recommend them, as I don't know anything about the product.

www.buylistenup.com/arp
 
alphamnemonic <shmotmail@gmail.com> wrote in
news:e7294911-213d-4734-b0cd-3386568e81a2@y38g2000hsy.googlegroups.com:

On Jul 7, 6:09 pm, Steve <nob...@nobody.com> wrote:
Steve <nob...@nobody.com> wrote
innews:Xns9AD0CDEF8F97Fnobodynobodycom@21
6.196.97.136:

alphamnemonic <shmotm...@gmail.com> wrote in
news:ba29f199-331f-48c1-ab96-28c3a81d42d8

@i18g2000prn.googlegroups.com:







On Jul 2, 6:20�pm, Steve <nob...@nobody.com> wrote:
s...@ece.drexel.edu wrote in news:16ea6110-be19-4a21-aecc-
10780259c...@e39g2000hsf.googlegroups.com:

On Jul 2, 3:35 pm, alphamnemonic <shmotm...@gmail.com> wrote:
Hi Everybody

This chip normally puts out square pulses. In the power supply
I am working on (http://www.laserfaq.org/sam/150rcsch.pdf) it
is putting out a sawtooth wave. I am testing it in 'standby
mode', in which Q4 is off and R33 is in control of the duty
cycle. Replacing the IC1 has no effect. Does anyone have any
ideas?

Where are you seeing sawtooths? �Pin 13?

--- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
�Repair | Main Table of Contents:http://www.repairfaq.org/R
EPAIR/
+Lasers | Sam's Laser
FAQ:http://www.repairfaq.org/sam/lasersam.htmďż˝ ďż˝
ďż˝ ďż˝ | Mirror
Sites:http://www.repairfaq.org/REPAIR/F_mirror
.html

Important: Anything sent to the email address in the message
header above is
ignored unless my full name AND either lasers or electronics is
included in the
subject line. �Or, you can contact me via the Feedback Form
in the
FAQs.

That is my question. Why do you have output A and output B (pin
11 and 14
)
grounded?

Also, pin 13 is VC in for the transistor collectors. Why do you
have this connected as an output?- Hide quoted text -

- Show quoted text -

Yes the sawtooth is on pin 13. Pin 13 is being used as an output
and pins 11 and 14 are grounded because the chip is being used in
single- ended supply mode (see
http://www.datasheetcatalog.org/datasheet/motorola/SG3525AN.pdfp.6
for an example of this configuration). I can see why you find that
strange--I did too!

I'd avoid the funky setup you have. In my opinion I'd connect pin
13 and 15 together and use either output A or B.

I'm not sure what Q4 is doing, I've never seen it used this way,
but you must know more than me since you designed this elaborte
circuit.

Keep us posted at what you do to resolve the problem.

I have been looking at the circuit and the datasheet.

I'm willing to bet the schematic is drawn wrong. It doesn't make any
sense to have pin 13 driving the base of a transistor.- Hide quoted
text
-

- Show quoted text -

The schematic is drawn correctly. This mode of operation is described
on p.6 of the datasheet (link is given in my post from July 3). I
removed the board and re-soldered R1 and R2, and the supply is now
working properly again. A rather boring fix, but if it works long term
I won't complain... If anyone else is having trouble with this supply,
I can send you waveforms captured with FlukeView from the working
unit. Thanks for the suggestions everyone.
Click to expand...
I'd like to see them. Do you have them in a format you can easily email?
 
"EADGBE" <hwbosshoss@comcast.net> wrote in message
news:b187f3aa-2038-40ff-b7ef-a4fd19966e55@25g2000hsx.googlegroups.com...
OK, I remembered that one of my other CD players--a Magnavox CDB650--
also has a digital output.

I patched it into the Yamaha preamp and got the same results--no right
channel sound.

I also tried another cable (dumb, I know--I'm still thinking
"analog"!) and got the same results.

I also tried using another one of the preamp's digital inputs and got
the same results.

So I can safely say that the fault lies somewhere inside the preamp.

Time to get out the hammer and duct tape......
Click to expand...


Far be it from me to say I told you so, so I won't.


Actually your original instincts were right. Digital either works or it
doesn't.



Gareth.
 
Father Guido <FG@no.where> wrote in message
news:5jao74t8016moovuv4ktn1auupemv3aa65@4ax.com...
I have an IR operated garbage can, trouble is the sensor is too
sensitive and it opens whenever you walk by. How can I reduce the
sensitivity of the IR receiver so I have to put my hand very close to
the sensor before the lid opens?

tia
Click to expand...

Try various thicknesses of different plastics , clear or opaque, but not
polythene, over the sensor


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
"N_Cook" <diverse@tcp.co.uk> wrote in message
news:g5hfte$q2a$1@registered.motzarella.org...
Father Guido <FG@no.where> wrote in message
news:5jao74t8016moovuv4ktn1auupemv3aa65@4ax.com...
I have an IR operated garbage can, trouble is the sensor is too
sensitive and it opens whenever you walk by. How can I reduce the
sensitivity of the IR receiver so I have to put my hand very close to
the sensor before the lid opens?

tia


Try various thicknesses of different plastics , clear or opaque, but not
polythene, over the sensor


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
Click to expand...
Or different colours of electricians' self-adhesive PVC tape.

Arfa
 
"Gareth Magennis" <gareth.magennis@ntlworld.com> wrote in message
news:63Rek.26925$E41.9858@text.news.virginmedia.com...
"EADGBE" <hwbosshoss@comcast.net> wrote in message
news:b187f3aa-2038-40ff-b7ef-a4fd19966e55@25g2000hsx.googlegroups.com...

OK, I remembered that one of my other CD players--a Magnavox CDB650--
also has a digital output.

I patched it into the Yamaha preamp and got the same results--no right
channel sound.

I also tried another cable (dumb, I know--I'm still thinking
"analog"!) and got the same results.

I also tried using another one of the preamp's digital inputs and got
the same results.

So I can safely say that the fault lies somewhere inside the preamp.

Time to get out the hammer and duct tape......



Far be it from me to say I told you so, so I won't.


Actually your original instincts were right. Digital either works or it
doesn't.



Gareth.
Click to expand...

As for the cause of the problem in tha pre-amp, one can only speculate even
more, we know how much fun that is. If you have a scope you can just follow
the signals from the D/A converter output onwards until one dissapears.

Could be anything at all really. It might be worth tapping and banging
things to see if it's a mechanical intermittent, other than that it's just
plain fault tracing. Could just be a selector switch. But I'm just
speculating again aren't I. Tch.




Gareth.
 
As Bob mentions, this is most likely to be caused by a microwave oven,
especially if it continues for a few minutes then stops completely. There's
nothing you can do except change the channel used for your video sender to
try and minimise it, use more directional aerials, or use a video sender
that uses a different band.

Regards,
Gary
 
"Don Pearce" <nospam@nospam.com> wrote in message
news:LuydnbbIeOKpDOHVnZ2dnUVZ8gydnZ2d@posted.plusnet...
Gareth Magennis wrote:
"EADGBE" <hwbosshoss@comcast.net> wrote in message
news:b187f3aa-2038-40ff-b7ef-a4fd19966e55@25g2000hsx.googlegroups.com...
OK, I remembered that one of my other CD players--a Magnavox CDB650--
also has a digital output.

I patched it into the Yamaha preamp and got the same results--no right
channel sound.

I also tried another cable (dumb, I know--I'm still thinking
"analog"!) and got the same results.

I also tried using another one of the preamp's digital inputs and got
the same results.

So I can safely say that the fault lies somewhere inside the preamp.

Time to get out the hammer and duct tape......



Far be it from me to say I told you so, so I won't.


Actually your original instincts were right. Digital either works or it
doesn't.



Gareth.

Ah, you don't have a DAB radio then? The background sound of boiling mud
in low signal conditions is a joy.

d
Click to expand...
LOL !!

Arfa
 
"Don Pearce" wrote ...
Gareth Magennis wrote:
Actually your original instincts were right. Digital either works or it
doesn't.

Ah, you don't have a DAB radio then? The background sound of boiling mud
in low signal conditions is a joy.
Click to expand...
But that IS "working" according to the people who specified
and designed the system. The low-level hash was determined to
be an acceptable tradeoff in the overall scheme. (Compare the
performance of MP3, etc.)
 
In article <3juo74hdntjnc2u5gul0280hioiqpr9hp0@4ax.com>,
Thor <Thor@nospam.net> wrote:

On Mon, 14 Jul 2008 12:26:21 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:


Thor wrote:

I am now in the belief that I do not need antistatic tape. I saw on, of
all
placec, Youtube a fellow take apart and repair an ipod. He used or he said
he
used antistatic tap to tape down the ribbon cable on the LCD. I don't see
why I
can't use a good quality black electrical tape, I have some very good 3M
tape
here.
I think this ends my hunt for something rather expensive that I really
don't
need.

Thanks to everyone for helping.


That tape won't hold very well. It is designed to stick to itself,
and the adhesive tends to bleed and dry out, over time. The proper tape
will hold tighter and longer.


This is the problem, I do not know what "the proper tape" is exactly. I am
completly open to suggestions if you have any, a link or two would be great.
I
did sit on search engines for several hours searching, I just don't know what
I
am looking for.


Thor
Click to expand...
You might try Kapton tape. But it seems to me that your biggest problem
is you don't want to pay for shipping. So it's unlikely that you're
going to be able to proceed with the adventure at all.

Personally, I appreciate the internet for worldwide access to things. A
couple of dollars for shipping is nothing compared to hours of driving
around town, burning up gas at $4.79/gallon, talking to the retarded
high school students employed at local stores, and coming home either
empty-handed or with the wrong stuff.

If the tape costs $10, and the shipping is $8, then the tape costs $18.
If it's 18 yards, then that's less than 3 cents per inch. How much are
you going to use on an ipod? An inch? So that's 3 cents. Too pricey for
you? Then cross "entrepreneur" off your vocabulary list.
 
"EADGBE" <hwbosshoss@comcast.net> wrote in message
news:0ea36639-9961-4315-a328-e06b4f5fbcfa@y21g2000hsf.googlegroups.com...
On Jul 14, 7:12 pm, "Gareth Magennis" <gareth.magen...@ntlworld.com>
wrote:
Far be it from me to say I told you so, so I won't.

Actually your original instincts were right. Digital either works or it
doesn't.

Gareth.

Gareth:

Oh, I never doubted your assessment.
Click to expand...
<snip>

In reality, none of us did really. We wuz jus' messin' wiv ya and adding a
bit of interesting debate to the issue ... d;~}

Arfa
 
That is a common problem with large screen crt sets, the east west
correction circuit has failed but some times caused by dry joints on the
circuit board.
If not DJ's you need a circuit diagram to be able to fix it as Sony uses
sometimes an unusual way to achieve east west correction.

Will
<sidneybek@yahoo.com> wrote in message
news:aa0e81a9-e570-4300-9aaf-2f7ea30091ed@m3g2000hsc.googlegroups.com...
36" sony HDTV tv model:KV-36XBR400,chassis:SCC-S48B-A (Canadian) or
SCC-S47B (USA),chassis: DX-1A,year:Sept 2000,flat screen
crt.Problem:according to customer intermittently the sides of the
picture (left & right) are bowed in (hourglass effect). Anyone have
any common repair tips?.Thanks in advance.

Sidney
E-mail: sidneybek(at)yahoo.com
Dartmouth,Nova Scotia
Canada
Click to expand...
 
"Don Pearce" <nospam@nospam.com> wrote in message
news:lZidnS_hQbHwOODVnZ2dnUVZ8vydnZ2d@posted.plusnet...
Richard Crowley wrote:
"Don Pearce" wrote ...
Gareth Magennis wrote:
Actually your original instincts were right. Digital either works or
it doesn't.
Ah, you don't have a DAB radio then? The background sound of boiling mud
in low signal conditions is a joy.

But that IS "working" according to the people who specified
and designed the system. The low-level hash was determined to
be an acceptable tradeoff in the overall scheme. (Compare the
performance of MP3, etc.)

I don't mean that, I mean this - what happens when there isn't enough
signal strength.

http://81.174.169.10/odds/baddab.mp3

d
Click to expand...

That sounds like John Humphrys pretending to be a Dalek.
I think its slightly less annoying than FM radio on the edge of reception,
where it would sound like he was pretending to be a force 9 gale in mono.



Gareth.
 
"Don Pearce" <nospam@nospam.com> wrote in message
news:zKKdneOVGaFCMODVnZ2dnUVZ8sednZ2d@posted.plusnet...
Gareth Magennis wrote:
"Don Pearce" <nospam@nospam.com> wrote in message
news:lZidnS_hQbHwOODVnZ2dnUVZ8vydnZ2d@posted.plusnet...
Richard Crowley wrote:
"Don Pearce" wrote ...
Gareth Magennis wrote:
Actually your original instincts were right. Digital either works or
it doesn't.
Ah, you don't have a DAB radio then? The background sound of boiling
mud in low signal conditions is a joy.
But that IS "working" according to the people who specified
and designed the system. The low-level hash was determined to
be an acceptable tradeoff in the overall scheme. (Compare the
performance of MP3, etc.)
I don't mean that, I mean this - what happens when there isn't enough
signal strength.

http://81.174.169.10/odds/baddab.mp3

d


That sounds like John Humphrys pretending to be a Dalek.
I think its slightly less annoying than FM radio on the edge of
reception, where it would sound like he was pretending to be a force 9
gale in mono.



Gareth.

Yes, but there is an important difference - the FM signal drops into noise
gracefully and slowly. That DAB signal is only 1dB or so bigger than one
that is not received at all, and 1dB bigger again would be received
cleanly.

d
Click to expand...
I think that when push comes to shove, a lot of the 'digital revolution',
including DAB, is about money, not any advantage to the consumer. DTTV
clearly shows this where, despite the limited bandwidth available for
transmissions, government and the regulators, continue to sell licences to
every little tinpot Tom Dick and Harry station, which then get crammed into
yet another multiplex, until there's no longer enough space left there for
everyone to get in a decent bitrate, whereupon it's discretely downed, and
stations start to get on the edge of Dalekism. Likewise, TV stations start
to have objectionable motion artifacts to the point of area blocking on some
of the worst affected ones.

That's not to say that digital transmissions *can't* be good in terms of
viewability and listenability. A 'good' full bitrate DAB transmission, or
better yet a radio or full bitrate satellite channel, can be excellent and
at least up to, if not exceeding a comparable analogue transmission of full
quality. It's just a shame that no matter how good the starting point, a
coupla dB is the difference between reception and digital cliff. Personally,
I'm with Don on that one, and I'd rather see the picture or hear the sound,
gradually deteriorate, as the signal level falls off.

So, is Freesat going to knock Freeview on the head ? I can't see any reason
why not, and can see one very good reason why it might.

HD

And that brings us back to the bandwidth issue ...

Arfa
 
In article <i49r7456tdd0ec8qeuabktm7klftgchqse@4ax.com>,
Thor <Thor@nospam.net> wrote:

On Tue, 15 Jul 2008 08:24:11 -0700, Smitty Two <prestwhich@earthlink.net
wrote:

In article <3juo74hdntjnc2u5gul0280hioiqpr9hp0@4ax.com>,
Thor <Thor@nospam.net> wrote:

On Mon, 14 Jul 2008 12:26:21 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:


Thor wrote:

I am now in the belief that I do not need antistatic tape. I saw on, of
all
placec, Youtube a fellow take apart and repair an ipod. He used or he
said
he
used antistatic tap to tape down the ribbon cable on the LCD. I don't
see
why I
can't use a good quality black electrical tape, I have some very good
3M
tape
here.
I think this ends my hunt for something rather expensive that I really
don't
need.

Thanks to everyone for helping.


That tape won't hold very well. It is designed to stick to itself,
and the adhesive tends to bleed and dry out, over time. The proper tape
will hold tighter and longer.


This is the problem, I do not know what "the proper tape" is exactly. I am
completly open to suggestions if you have any, a link or two would be
great.
I
did sit on search engines for several hours searching, I just don't know
what
I
am looking for.


Thor

You might try Kapton tape. But it seems to me that your biggest problem
is you don't want to pay for shipping. So it's unlikely that you're
going to be able to proceed with the adventure at all.

Personally, I appreciate the internet for worldwide access to things. A
couple of dollars for shipping is nothing compared to hours of driving
around town, burning up gas at $4.79/gallon, talking to the retarded
high school students employed at local stores, and coming home either
empty-handed or with the wrong stuff.

If the tape costs $10, and the shipping is $8, then the tape costs $18.
If it's 18 yards, then that's less than 3 cents per inch. How much are
you going to use on an ipod? An inch? So that's 3 cents. Too pricey for
you? Then cross "entrepreneur" off your vocabulary list.

Thanks for the Kapton tape tip.

I am taking Michaels advice , instead of email I am using the telephone.

I am doing this for my self and have no plans of ever doing this for anyone
else. I am not an "entrepreneur" and the word "entrepreneur" is only in my
vocabulary for reference. I do not have a business, never have wanted a
business
and never will.

I am just looking for an inexpensive roll of antistatic tape.


Thank you for your efforts,
Thor
Click to expand...
You wrote:

"It is going to be used to hold down LCD displays and lithium
batteries....

At this point in time I will be using the tape doing Ipod repairs. I
don't want a mess to deal with when I get back into them at a later
date."

That sure makes it sound like multiple units, to be taken apart multiple
times. Pardon me for assuming you were going into the ipod repair
business.
 
In article <i49r7456tdd0ec8qeuabktm7klftgchqse@4ax.com>, thor@nospam.net wrote:
On Tue, 15 Jul 2008 08:24:11 -0700, Smitty Two <prestwhich@earthlink.net
wrote:

In article <3juo74hdntjnc2u5gul0280hioiqpr9hp0@4ax.com>,
Thor <Thor@nospam.net> wrote:

On Mon, 14 Jul 2008 12:26:21 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:


Thor wrote:

I am now in the belief that I do not need antistatic tape. I saw on, of
all
placec, Youtube a fellow take apart and repair an ipod. He used or he
said
he
used antistatic tap to tape down the ribbon cable on the LCD. I don't see

why I
can't use a good quality black electrical tape, I have some very good 3M
tape
here.
I think this ends my hunt for something rather expensive that I really
don't
need.

Thanks to everyone for helping.


That tape won't hold very well. It is designed to stick to itself,
and the adhesive tends to bleed and dry out, over time. The proper tape
will hold tighter and longer.


This is the problem, I do not know what "the proper tape" is exactly. I am
completly open to suggestions if you have any, a link or two would be great.

I
did sit on search engines for several hours searching, I just don't know
what
I
am looking for.


Thor

You might try Kapton tape. But it seems to me that your biggest problem
is you don't want to pay for shipping. So it's unlikely that you're
going to be able to proceed with the adventure at all.

Personally, I appreciate the internet for worldwide access to things. A
couple of dollars for shipping is nothing compared to hours of driving
around town, burning up gas at $4.79/gallon, talking to the retarded
high school students employed at local stores, and coming home either
empty-handed or with the wrong stuff.

If the tape costs $10, and the shipping is $8, then the tape costs $18.
If it's 18 yards, then that's less than 3 cents per inch. How much are
you going to use on an ipod? An inch? So that's 3 cents. Too pricey for
you? Then cross "entrepreneur" off your vocabulary list.

Thanks for the Kapton tape tip.

I am taking Michaels advice , instead of email I am using the telephone.

I am doing this for my self and have no plans of ever doing this for anyone
else. I am not an "entrepreneur" and the word "entrepreneur" is only in my
vocabulary for reference. I do not have a business, never have wanted a
business
and never will.

I am just looking for an inexpensive roll of antistatic tape.


Thank you for your efforts,
Thor
Click to expand...
Many antistatic things are conductive. Putting amy tape on just requires care
and a long lasting adhesive. Interesting many tapes are charged so the adhesive
stays on.

greg
 
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