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SONY LCD TV problem kdl-22BX200
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Bob Minchin
Jan 11, 2012, 6:40:57 AM1/11/12
to
This TV has sound but no picture. A couple of seconds after switch on,
the fluorescent tubes strike but then go out a second or so later.
Power light flashes about 8 times and then stays solid green.
So far I have not found a source of a manual despite a fairly thorough
search.
In the event of some sort of picture failure, is it normal for the tubes
to switch off or is the main problem that they won't stay on eg excess
current or maybe over voltage?
I have found 3 surface mount fuses and each is intact
voltages at those point s seems to be 1.25v 3.5v and nearly 13v which
could be a rather high 12v.
Voltage drops across the 1.25v and 3.5v fuses are a few 10s of mV but
the drop across the 12-13v fuse is only 1-2mV suggesting low current
draw at 12v.
Has any one got any related Sony LCD TV experience or a source of
manuals please.
TIA
Bob
the fluorescent tubes strike but then go out a second or so later.
Power light flashes about 8 times and then stays solid green.
So far I have not found a source of a manual despite a fairly thorough
search.
In the event of some sort of picture failure, is it normal for the tubes
to switch off or is the main problem that they won't stay on eg excess
current or maybe over voltage?
I have found 3 surface mount fuses and each is intact
voltages at those point s seems to be 1.25v 3.5v and nearly 13v which
could be a rather high 12v.
Voltage drops across the 1.25v and 3.5v fuses are a few 10s of mV but
the drop across the 12-13v fuse is only 1-2mV suggesting low current
draw at 12v.
Has any one got any related Sony LCD TV experience or a source of
manuals please.
TIA
Bob
Andy Burns
Jan 11, 2012, 6:44:40 AM1/11/12
to
Bob Minchin wrote:
> This TV has sound but no picture. A couple of seconds after switch on,
> the fluorescent tubes strike but then go out a second or so later.
If you shine a bright torch on the screen from various angles can you
> This TV has sound but no picture. A couple of seconds after switch on,
> the fluorescent tubes strike but then go out a second or so later.
see any semblance of a picture? i.e. is it just the lack of backlight
causing lack of visible picture?
Message has been deleted
Bob Minchin
Jan 11, 2012, 7:51:40 AM1/11/12
to
Yes I can see a faint picture. So I guess it is a backlight problem?
So if the tubes strike but draw too much current they would behave like
this?
Bob
Bob Minchin
Jan 11, 2012, 8:03:13 AM1/11/12
to
Martin wrote:
> In general Sony TV manuals are at Sony support.
> http://www.sony.co.uk/support/en
>
> http://www.sony.co.uk/support/en/product/KDL-22BX200
>
> For what it is worth -
> http://pdf.crse.com/manuals/419304112X.pdf
Thanks Martin,
I should have been clearer, I need a service manual. I have found one
paid for service manual which I ordered but the seller informed me that
it had no circuits so I've cancelled that one.
Bob
> http://www.sony.co.uk/support/en
>
> http://www.sony.co.uk/support/en/product/KDL-22BX200
>
> For what it is worth -
> http://pdf.crse.com/manuals/419304112X.pdf
Thanks Martin,
I should have been clearer, I need a service manual. I have found one
paid for service manual which I ordered but the seller informed me that
it had no circuits so I've cancelled that one.
Bob
Andy Burns
Jan 11, 2012, 8:26:19 AM1/11/12
to
Bob Minchin wrote:
> Yes I can see a faint picture. So I guess it is a backlight problem?
> So if the tubes strike but draw too much current they would behave like
> this?
I don't know. There are replacement CCFL and/or inverter kits available
> Yes I can see a faint picture. So I guess it is a backlight problem?
> So if the tubes strike but draw too much current they would behave like
> this?
(ebay etc) for laptop sized screens, not sure if they're easily
available for TVs ...
fred
Jan 11, 2012, 8:36:39 AM1/11/12
to
In article <jek0l5$o4k$1...@dont-email.me>, Bob Minchin
<bob.minc...@YOURHATntlworld.com> writes
That's certainly the case on inverters for cold cathode backlight lamps
on monitors, the they monitor the tube current and if the lamp doesn't
strike within 2s or so then they shut the inverter down to avoid damage
(to both). During the strike phase they output voltages in the 1kV or so
range which folds back to a lower level when running.
A monitor that I had used 4 tubes, 2 top, 2 bottom with 4 separate feeds
to the lamps split off 2 transformers, drivers and a dual channel
controller chip. The chip controlled the shut down and if a single tube
failed to strike then all lamps where turned off.
If you don't mind dismantling the screen to get direct sight on the
tubes then you can usually spot what is going on. Replacement lamps can
be obtained at reasonable cost but if one set stays off altogether then
it might be an inverter problem and they aren't so cheap. Pink or
obviously dim tubes are on the way out. Alternatively, connecting just
one tube at a time to the inverter would give you a chance to look at
each tube in isolation to see if one is out completely or dim during the
2s blink and it could be done before dismantling.
In the end, mine was an inverter fault following a tube failure (common)
so I disabled one side of the controller (surface mount bodgery) and ran
the 2 good tubes (1 top, 1 bottom) off the other inverter channel.
--
fred
it's a ba-na-na . . . .
<bob.minc...@YOURHATntlworld.com> writes
on monitors, the they monitor the tube current and if the lamp doesn't
strike within 2s or so then they shut the inverter down to avoid damage
(to both). During the strike phase they output voltages in the 1kV or so
range which folds back to a lower level when running.
A monitor that I had used 4 tubes, 2 top, 2 bottom with 4 separate feeds
to the lamps split off 2 transformers, drivers and a dual channel
controller chip. The chip controlled the shut down and if a single tube
failed to strike then all lamps where turned off.
If you don't mind dismantling the screen to get direct sight on the
tubes then you can usually spot what is going on. Replacement lamps can
be obtained at reasonable cost but if one set stays off altogether then
it might be an inverter problem and they aren't so cheap. Pink or
obviously dim tubes are on the way out. Alternatively, connecting just
one tube at a time to the inverter would give you a chance to look at
each tube in isolation to see if one is out completely or dim during the
2s blink and it could be done before dismantling.
In the end, mine was an inverter fault following a tube failure (common)
so I disabled one side of the controller (surface mount bodgery) and ran
the 2 good tubes (1 top, 1 bottom) off the other inverter channel.
--
fred
it's a ba-na-na . . . .
Bob Minchin
Jan 11, 2012, 8:40:44 AM1/11/12
to
not all would fail at once or if the PSU is knackered or what.
Seems a shame to toss it away but possible not worth spending much money
or time on it.
Bob
John Williamson
Jan 11, 2012, 8:53:46 AM1/11/12
to
better cassette recorders, I found them very helpful until the spares
stock ran out about 15 years after they stopped making them. As were my
local Sony approved repairers.
--
Tciao for Now!
John.
Dave Plowman (News)
Jan 11, 2012, 9:06:53 AM1/11/12
to
In article <9n5ija...@mid.individual.net>,
reasonable.
--
*A snooze button is a poor substitute for no alarm clock at all *
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
John Williamson <johnwil...@btinternet.com> wrote:
> You could always send Sony UK support an e-mail. When I had one of their
> better cassette recorders, I found them very helpful until the spares
> stock ran out about 15 years after they stopped making them. As were my
> local Sony approved repairers.
Last time I used them they new how to charge for spares. Made Philips seem
> You could always send Sony UK support an e-mail. When I had one of their
> better cassette recorders, I found them very helpful until the spares
> stock ran out about 15 years after they stopped making them. As were my
> local Sony approved repairers.
reasonable.
--
*A snooze button is a poor substitute for no alarm clock at all *
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Bob Minchin
Jan 11, 2012, 12:02:07 PM1/11/12
to
I've not got to the taking it apart stage yet - I did that with a laptop
once to change the tube - horrible job - everything is so flimsy once apart!
Pulling off the 4 inverter connections in turn has not given any clues
as the unplugged ones over-volt immediately. I might try loading them
with a resistor but the circuit might be looking for the non linear
resistance curve of a tube if it is really clever.
Not sure what the power for each tube would be - got to be a few watts
and a few hundred volts once struck. So maybe 40kohms ish??
Total power consumption is 43watts according to the label so maybe half
that for the screen?
Maybe I'll have a play when I've more time.
I only got the TV off freecycle last night as a "spares or repair" so it
might go back that way.
Bob
fred
Jan 11, 2012, 3:25:22 PM1/11/12
to
In article <jekfar$cu8$1...@dont-email.me>, Bob Minchin
<bob.minc...@YOURHATntlworld.com> writes
>
a run voltage of 600V (quick look, maybe check data) which suggests a
resistance of 120k but at 3W so better use a chain of resistors to
survive volts and power. No need to go daft though if it's only on for a
second or 2.
Insulate and keep the hands well clear though.
True recycling/DIY, good luck!
<bob.minc...@YOURHATntlworld.com> writes
>
>I've not got to the taking it apart stage yet - I did that with a laptop
>once to change the tube - horrible job - everything is so flimsy once apart!
>Pulling off the 4 inverter connections in turn has not given any clues
>as the unplugged ones over-volt immediately. I might try loading them
>with a resistor but the circuit might be looking for the non linear
>resistance curve of a tube if it is really clever.
>Not sure what the power for each tube would be - got to be a few watts
>and a few hundred volts once struck. So maybe 40kohms ish??
>Total power consumption is 43watts according to the label so maybe half
>that for the screen?
>Maybe I'll have a play when I've more time.
>I only got the TV off freecycle last night as a "spares or repair" so it
>might go back that way.
>
The tubes I've looked at were 5mA or so and I am guessing they will have
>once to change the tube - horrible job - everything is so flimsy once apart!
>Pulling off the 4 inverter connections in turn has not given any clues
>as the unplugged ones over-volt immediately. I might try loading them
>with a resistor but the circuit might be looking for the non linear
>resistance curve of a tube if it is really clever.
>Not sure what the power for each tube would be - got to be a few watts
>and a few hundred volts once struck. So maybe 40kohms ish??
>Total power consumption is 43watts according to the label so maybe half
>that for the screen?
>Maybe I'll have a play when I've more time.
>I only got the TV off freecycle last night as a "spares or repair" so it
>might go back that way.
>
a run voltage of 600V (quick look, maybe check data) which suggests a
resistance of 120k but at 3W so better use a chain of resistors to
survive volts and power. No need to go daft though if it's only on for a
second or 2.
Insulate and keep the hands well clear though.
True recycling/DIY, good luck!
Lee
Jan 12, 2012, 6:14:43 AM1/12/12
to
On 11/01/2012 11:40, Bob Minchin wrote:
> So far I have not found a source of a manual despite a fairly thorough
> search.
>
That TV seems to have an AZ1K-5-3 chassis. I can't find anything much on
> So far I have not found a source of a manual despite a fairly thorough
> search.
>
that variant either, I wonder how many basic design features it shares
with the more common AZ1K chassis?
Although that is a big screen chassis so the actual inverters are
probably very different.
As usual I'd esr the caps before condemning the inverters, although the
inverters do seem to fail on Sony sets...
Lee
Jan 12, 2012, 6:24:01 AM1/12/12
to
After some searching I found a manual for the later KDL-22BX300 which
uses the AZ1-FK chassis, it may have enough common features to be
useful.Plus it's the same size screen so may use similar inverters:
http://elektrotanya.com/sony_kdl-22bx300_32bx300_chassis_az1-fk_level-3_confidental_sm.pdf/download.html
Lee
uses the AZ1-FK chassis, it may have enough common features to be
useful.Plus it's the same size screen so may use similar inverters:
http://elektrotanya.com/sony_kdl-22bx300_32bx300_chassis_az1-fk_level-3_confidental_sm.pdf/download.html
Lee
Bob Minchin
Jan 12, 2012, 12:22:02 PM1/12/12
to
Thank you very much for taking the trouble to post a link to that manual.
The model is different and the inverter is different but it does give me
some ideas for the sort of circuitry they use.
I've also used the site to get a manual for our main Bravia TV
No problems with that yet but good insurance to have the manual just in
case.
Much appreciated
Bob
Lee
Jan 12, 2012, 2:11:08 PM1/12/12
to
On 12/01/2012 17:22, Bob Minchin wrote:
>
> Much appreciated
>
> Bob
No probs :)
I still reckon it's caps though! :)
Lee
>
> Much appreciated
>
> Bob
No probs :)
I still reckon it's caps though! :)
Lee
Bob Minchin
Jan 12, 2012, 3:27:55 PM1/12/12
to
The main PSU is fine. The inverter in your service sheet only has small
value caps in the inverter and the tubes are run on AC.
Cheers
Bob
Lee
Jan 12, 2012, 4:04:30 PM1/12/12
to
common cause of backlight/inverter failure. Even if the rails appear to
measure correctly.
I take it you've 'scoped the PSU rails to check for noise?
Lee
Lee
Jan 12, 2012, 6:41:11 PM1/12/12
to
Doh! while I did mean *the* low esr caps give trouble I *meant* to say
by drifting high esr.
But you all knew what I meant ;)
Lee
by drifting high esr.
But you all knew what I meant ;)
Lee
loz...@hotmail.com
Oct 23, 2013, 2:26:59 PM10/23/13
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