Toshiba TV29C90 problem; Image fades to black...

[xray]

On Tue, 03 Jan 2006 21:03:29 GMT, Ignoramus29795
<ignoramus29795@NOSPAM.29795.invalid> wrote:

I changed my mind. I will not sell my 475.

Now... I have little interest in homemade radio or audio stuff. So far
my little forays into electronics centered around power electronics.
Given that... Is there any possible reason to keep a spectrum
analyzer?

Sorry, I'm late to this thread but thought I'd add an opinion.

No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

What are the specifications of the one you have? Maybe I can save you
grief by taking it off your hands with a preimuim bid since it is just a
glorified scope?

P.s. You never answered if the Motorcycle engine you are selling is the
one that came by accident.

 

[Paul Burridge]

On Sat, 07 Jan 2006 04:38:08 -0800, xray <notreally@hotmail.invalid>
wrote:

Sorry, I'm late to this thread but thought I'd add an opinion.

No one can stop you doing that.

No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

What are the specifications of the one you have? Maybe I can save you
grief by taking it off your hands with a preimuim bid since it is just a
glorified scope?

It's a different thing altogether!

Barely a week went by before I deeply regretted parting with my
spectrum analyser. :-(
--

"What is now proved was once only imagin'd" - William Blake

 

[Jim Yanik]

"Ancient_Hacker" <grg2@comcast.net> wrote in
news:1136587491.782445.289920@g43g2000cwa.googlegroups.com:

I have several Tek 485's on the to-repair shelf. IIRC they have about
six power supply voltages and if any one of them gets out of spec the
whole thing shuts down. Then it's kinda hard to figure out which one
went blooey first. Grrr....

Access to the PS for troubleshooting and repair is terrible,too.
That HV assy is buried in the middle of the scope,and it has a sense
line,too!

--
Jim Yanik
jyanik
at
kua.net

 

[Rich Grise, but drunk]

On Sat, 07 Jan 2006 16:55:00 +0100, Paul Burridge wrote:

On Sat, 07 Jan 2006 04:38:08 -0800, xray <notreally@hotmail.invalid
wrote:

Sorry, I'm late to this thread but thought I'd add an opinion.

No one can stop you doing that.

No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

Not to mention incredible amounts of fun! (look at a pulse's
spectrum sometime, and twirl the PRF and PW knobs and watch the pretty
pictures dance...)

What are the specifications of the one you have? Maybe I can save you
grief by taking it off your hands with a preimuim bid since it is just a
glorified scope?

It's a different thing altogether!

Barely a week went by before I deeply regretted parting with my
spectrum analyser. :-(

Not only that, but its very name is ripe for _so_ many play-on-words
jokes! "rectum analyzer?" "spectrum ANAL-izer?" etc.... ;-)

Cheers!
Rich

 

[clifto]

Paul Burridge wrote:

xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

No, they're garbage.

I have a really nice garbage can in case anyone wants.

--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.

 

[maxfoo]

On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com> wrote:

Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

No, they're garbage.

I have a really nice garbage can in case anyone wants.

Will it do phase noise measurements for me?

 

[clifto]

maxfoo wrote:

On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com> wrote:
Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

No, they're garbage.

I have a really nice garbage can in case anyone wants.

Will it do phase noise measurements for me?

Only if someone sends me the right kind of garbage.

--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.

 

[Franc Zabkar]

On 7 Jan 2006 19:52:47 -0800, "larry moe 'n curly"
<larrymoencurly@my-deja.com> put finger to keyboard and composed:

I have some 350W Fortron-Sparkle model FSP-350BU PSUs with empty spots
where a thermistor and fixed resistor would normally be connected in
series, and I'd like to know their purpose. I think that they connect
this way:

http://static.flickr.com/39/83308555_59e5e557a6_o.jpg

Capacitor C10 and pin 18 are on the small vertical circuit board
(beneath the removed fan controller board in the photo below) housing
the Fairchild KA3511DS PSU controller chip, and according to the
datasheet at

www.ortodoxism.ro/datasheets/fairchild/KA3511.pdf

pin 18 is the Extra Protection (EP) input, which, when its voltage goes
high enough, is supposed to shut down the PSU. In other words, this
seems to rule out the thermistor being used as a overheat sensor
because the pin 18 is low anyway in normal operation.

Here are where the missing resistor and thermistor are located (circled
in red):

http://static.flickr.com/39/83310554_91d773cf62.jpg

This thermistor is not for fan speed control -- that's handled by
another thermistor (next to the screw on the heatsink, higher up in the
picture).

I suspect the PT (extra protection) input may be a current sensing
input. I don't understand the purpose of the thermistor, though,
unless it is there to derate the PSU at higher temperatures.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Arfa Daily]

"Goldenshuttle" <goldenshuttle@hotmail.com> wrote in message
news:1136960343.628929.319950@o13g2000cwo.googlegroups.com...

Hi Guys
If we add a bridge rectifier to the output of light Dimmer to make a DC
motor control.....would it work ? did any of U pals try it ???

In principle, depending on the motor type and loading, it might. Possible
issues are noisy mechanical operation of the motor, particularly at low
speed, and interference pushed back up the power lines. Being an inductive
load, for which the dimmer is not designed, it may fail to work completely,
even though the motor is ' isolated ' by the bridge. Would have thought that
a better alternative would be to build or buy a proper motor controller ...

Arfa

 

[tekamn]

Agreed. No component level repair, no schematics. Custom ordered smps
power supplies.

The power supplies have sometimes nasty field failures. I remmeber a
few TDS3xx series scopes I had to repair. Always a burned out start-up
resistor to replace. Hard to discover, but after doing this once:
repair of the othe scopes was quickly to be done ;-)

Andreas

 

[tekamn]

For history, check www.tektronix.com, and do a search for "7000".
Worked well last time I tried, and gives a little bit of history and
price info. Better: The site at rutgers.edu , link is mentioned below
by another poster.

hth,
Andreas

 

[Mark D. Zacharias]

Samsung's quality and customer service have been improving - but your friend
should not expect any of the newer high-tech type displays to be absolutely
trouble-free. LCD, DLP, Plasma - they all have issues and potential issues.

Mark Z.


"Bob Kos" <see@text.for.eddress> wrote in message
news:kjZwf.3798$WY5.911@newsread2.news.pas.earthlink.net...

Hi All:

I have a friend who is looking at a Samsung HCR-4755WX TV for purchase.
Sam's club is selling them for around $1000. He likes the picture and
features. He is unfamiliar with Samsung TV products as far as reliability
and serviceability. Me too. Are there any opinions or experiences from
the
group regarding this particular model or Samsung HT RP TVs in general?
All
advice appreciated

 

[Leonard Caillouet]

Post the brand, model, and chassis. Post the info that others have asked
for, too. More info yields better advice. Less info yields guesses, except
from the true psychics on this group. Actually, I guess a true psychic
would not need to read the group at all. Maybe phychos is more likely on
usenet...

Most likely thing would be an open resistor, but with HV arcing things can
get unpredictable.

Could be unrelated to the arcing, if the arcing was caused by a coolant leak
like we see on some of the RCA sets. Could also be that the CRT was
damaged.

Leonard

"Charon" <ebauld@gmail.com> wrote in message
news:1136957481.699654.195640@g44g2000cwa.googlegroups.com...

I have an older crt projection big screen and I now have retrace lines
that appeared after turnning the set on a few times and hearing a arc
immediatly when turnning on. I waited too long to fix the arc and it
has affected something else.

The arcing was comming from the Red CRT from under the node and arcing
to the chassis, I have since fixed this but have been unable to track
down what is causing the retrace lines. The B+ voltage appears correct
but I do not have an oscilloscope to test ripple in any of the parts.
Any one know what the arcing may have effected ? The blanking circut or
perhaps from the flyback backwards ?

 

[geno419@yahoo.com]

Charon wrote:

I have an older crt projection big screen and I now have retrace lines
that appeared after turnning the set on a few times and hearing a arc
immediatly when turnning on. I waited too long to fix the arc and it
has affected something else.

The arcing was comming from the Red CRT from under the node and arcing
to the chassis, I have since fixed this but have been unable to track
down what is causing the retrace lines. The B+ voltage appears correct
but I do not have an oscilloscope to test ripple in any of the parts.
Any one know what the arcing may have effected ? The blanking circut or
perhaps from the flyback backwards ?

It's usually a driver or output filter circuit resistor/capacitor open
or change in value,
guess you will have to test by substitution. Could also be crt did you
try swapping the
crt drive boards? If the lines go away its in the drive circuit if
they stay then it probably the
red crt.

 

[Asimov]

"Goldenshuttle" bravely wrote to "All" (10 Jan 06 22:19:03)
--- on the heady topic of "DC motor Control"

Go> From: "Goldenshuttle" <goldenshuttle@hotmail.com>
Go> Xref: core-easynews sci.electronics.repair:354800

Go> Hi Guys
Go> If we add a bridge rectifier to the output of light Dimmer to make a
Go> DC motor control.....would it work ? did any of U pals try it ???


Should work fine but use some type of filtering to keep the rfi hash
down. If you use a filter cap the motor will see only a constant DC
that you can vary. The control will feel rubbery however.

For example when the motor is stopped the control will have to be
turned up a lot before the motor starts to rotate and then the motor
will speed up far more than expected so the control has to be turned
back down a lot.

One way around this is to make the control dependant on motor current.
For instance an optical feedback of motor current. This way the
position of the control will become almost equal to motor speed. In
other words the circuit automatically applies a greater voltage to get
the motor started and then the motor current turns back the voltage.
It does however require more circuitry than just a simple dimmer.

A*s*i*m*o*v

 

[Mike Berger]

It's not just Thomsen. Other manufacturers have different problems
with the same cause (depending on how they handle the two ambiguous
bits). This will have to be fixed by the broadcasters, or this
generation of tv's will have many problems.

Dani wrote:

This trouble is caused by a defective data packet broadcast from a
local TV station. The data packet is located in
the VBI (Vertical Retrace Interval). It's purpose is for XDS (Extended
Data Services) that is used by the GemStar
circuitry. The condition is very intermittent and not much is known to
the average TV technician because Thomson

 

[floss]

b Wrote:

Hello everybody. I have a problem connecting my TV/VCR combo to my
new
DVD recorder.
Basically I have my combo TV and a freeview box which I'd like to
connect to the DVD recorder.
If anyone knows of a way around the problem I would be very pleased
to
hear from you. I'm getting disheartened!!

B wrote:
Try this:
1.connect the aerial to the freeview box.
2. connect the freeview box via scart to the dvd recorder. This will
allow you to record in better quality from freeview - just select
the
dvd's 'AV' /'ext' input.
3. connect an rf cable from the freeview's output to the dvd aerial
input.(this will allow you to record from normal analogue tv
channels).

4. connect another rf cable from the dvd 's RFoutput to the aerial
socket on the combo.

5. Finally, tune the combo Tv in to the dvd recorder. (before
starting
the tuning process, play a disc you know well so you know when you
find
the signal from the dvd unit) .
hope this helps, B.

Hi B

Thanks so much for taking the time to reply. I will definitely give
this a try. However I have more questions.... Is an RF cable the same
as a 'coaxial' cable?? Also I have two scart points on the DVDR, will
the scart lead from the freeview box go into the in or out scart? Sorry
if I'm asking silly questions. Just desperate get it right!!

Floss.


--
floss

 

[simon hanlon]

On further inspection it seems the brightness has gone strange, when you
turn it down on the remote it is still bright but stops the cycling of
colour tints. It is still slightly out of focus also

"JANA" <jana@ca.inter.net> wrote in message
news:42j6piF1j5b6lU2@uni-berlin.de...

This could be a cold solder on the CRT socket assembly, bad connection
between the focus grid of the CRT back to the focus supply, or a defect in
the high voltage multiplier, and or the CRT may be failing.

If you are not experienced in TV servicing and equipped to do so, it is
best
to give the set out for proper service. There are some serious safety
issues
with working inside of TV sets.

--

JANA
_____


"simon hanlon" <simonjhanlon@btopenworld.com> wrote in message
news:dq1ftk$lk8$1@news8.svr.pol.co.uk...
Model number 284248WNS
Powers up ok then immediately the screen has a yellow tint then changes to
red then blue...goes out of focus and back to normal..cycles like this
.takes about 6 seconds to go through a complete cycle.
any ideas

 

[floss]

Hi B,

Well, I tried your suggestions... I've made progress but I'm not there
yet.
When I first connected everything up, I had no picture or sound on my
TV. I then added the scart lead from my VCR port on the freeview box to
the scart on the TV. This gave me all the channels on freeview through
channel E1 on my TV. However the AV channel remains blank. When I
switch on the DVDR it plays the DVD but there is nothing playing on the
screen. I retuned my TV to see if it picks up the DVD but it did not. I
was also able to 'record' from the scart channel on the DVD but I am
unable to play whats recorded, just like the ordinary DVD.
What is channel E1? How can I move the cables round to record from
this, or make the channels appear on the AV channel?
Any ideas?

Floss.


--
floss

 

Try to tweak the G2 pot : you will see a fine and bright line across
the screen.
Turn off the set, and turn down G2 pot.
You have a fault in the vertical deflection!