TV fading in and out (AKAI)

A

amstereo

Guest
Hi,
Got a older akai (~6 - 8 yrs)

the other day, it started to fade to black then back to normal,

Its like power to the tube is failing - just a guess cause the brightness
goes to complete darkness, and when i press a button on the tele of remote,
the OSD fades as well so it's not the actual brightness control activating
it (i know this cause when youset the brightness level (using the remote)
the picture will fade to black but the OSD is still visible.

any idea what the cause is? i can place the problem back to when the
heatwave was on in brisbane - the actual problem began then and hasn't gone
away. Takes about an hour before the problem starts - then its continuous
until the tele cools down again.

heat related - just where the issue is, i dunno.
 
Probably a dry joint somewhere in the heater circuit to the CRT; probably on
the neck board itself. The gentle fade-out is the dead give-away; the
picture fades out as the heaters cool down, and fades in as they warm up
again, in respose to the dry joint opening and closing.

Usual disclaimer: Tying to fix a TV yourself can Kill or seriously injure
you. Picture tubes produce dangerous X-Ray radiation if incorrectly adjusted
and aligned. Unless you know precisely what you are doing, get it fixed
profesionally.


"amstereo" <amstereo@optushomeDOTcompanyDOTaustralia> wrote in message
news:4045a4b8$0$3953$afc38c87@news.optusnet.com.au...
Hi,
Got a older akai (~6 - 8 yrs)

the other day, it started to fade to black then back to normal,

Its like power to the tube is failing - just a guess cause the brightness
goes to complete darkness, and when i press a button on the tele of
remote,
the OSD fades as well so it's not the actual brightness control activating
it (i know this cause when youset the brightness level (using the remote)
the picture will fade to black but the OSD is still visible.

any idea what the cause is? i can place the problem back to when the
heatwave was on in brisbane - the actual problem began then and hasn't
gone
away. Takes about an hour before the problem starts - then its continuous
until the tele cools down again.

heat related - just where the issue is, i dunno.
Click to expand...
 
thanks fo the info-we have shock protection installed, i don't touch any
trim pots on the bnoard, and only power up when i'm not gonna touch it
(remote:) -

-thats an easy thing to rectify anyway, after this fix thats it, the tele's
done a frame chip, and a deflection coil since i've had it, after this, its
out.

any pointers af to where i mighth get hold of video screens (the type used
in video walls? i only ever use the tele as a monitor - vcr does tuning
cause its a stereo unit and its fed to the hi-fi for the audio.

i can fit a bigger unit in with one of these - less bulk
 
"amstereo" <amstereo@optushomeDOTcompanyDOTaustralia> wrote in message news:<4045cf48$0$14970$afc38c87@news.optusnet.com.au>...
thanks fo the info-we have shock protection installed, i don't touch any
trim pots on the bnoard, and only power up when i'm not gonna touch it
(remote:) -
Click to expand...
'Shock protection' will NOT stop you getting electrocuted mucking
around inside a TV set.

It MIGHT not even stop you getting electrocuted mucking around with
the mains, but that's another story.

Live long and keep out of it.

Mark
 
On 3 Mar 2004 14:55:07 -0800, mvandere@iprimus.com.au (Mark van der
Eynden) wrote:

"amstereo" <amstereo@optushomeDOTcompanyDOTaustralia> wrote in message news:<4045cf48$0$14970$afc38c87@news.optusnet.com.au>...
thanks fo the info-we have shock protection installed, i don't touch any
trim pots on the bnoard, and only power up when i'm not gonna touch it
(remote:) -


'Shock protection' will NOT stop you getting electrocuted mucking
around inside a TV set.

It MIGHT not even stop you getting electrocuted mucking around with
the mains, but that's another story.

Live long and keep out of it.

Mark
Click to expand...
Hello Mark,
I don't understand this attitude
"Live long and keep out of it."
I can understand your concern if this was a
basket weaving group and Mr Amstereo
mentioned his TV problem.

This is an electronics group for technically minded people
with an interest in electronics. I say to Mr Amstereo,
"get stuck into it, try and find out what is wrong with it"
I am sure Mr Amstereo is a grown up who understands
the dangers. He has been posting here for yonks.

I see more danger driving to the local shops than in the
back of a TV set. Watching young kids play on grassed
areas in a park or the beach scares me because of
syringes lying around or buried in the sand. I could
go on to other dangers, drinking, smoking etc, but you
get my drift.

Anyway, Mr Amstereo, check the things suggested
by others, give it a good eyeballing with a magnifying glass,
obtain the circuit if you can and have a bit of fun
searching for the faults and enjoy the satisfaction of fixing
it yourself.

Regards,
John Crighton
Hornsby
 
Hi John,
I agree with Mark, where or not Mr Amstereo uses this group a lot or not,
his use of whets wrong with his TV does ring warning bells that he may not
know how dangerous the inside of a TV set is,
and may think that his ELCB will protect him from electrocution, which we
all know it wont,
DON'T WE??
It he touches the EHT or anywhere in the Switch mode he can get a belt and
not trip the ELCB.
By all means learn as you go, but the info is TAKE CARE..
TVs kill... and Iam sure that no one would want to lose someone just because
everyone assumed he knew what he was doing..
Allan




"John Crighton" <john_c@tpg.com.au> wrote in message
news:4046cae4.7845187@News.individual.net...
On 3 Mar 2004 14:55:07 -0800, mvandere@iprimus.com.au (Mark van der
Eynden) wrote:

"amstereo" <amstereo@optushomeDOTcompanyDOTaustralia> wrote in message
news:<4045cf48$0$14970$afc38c87@news.optusnet.com.au>...
thanks fo the info-we have shock protection installed, i don't touch
any
trim pots on the bnoard, and only power up when i'm not gonna touch it
(remote:) -


'Shock protection' will NOT stop you getting electrocuted mucking
around inside a TV set.

It MIGHT not even stop you getting electrocuted mucking around with
the mains, but that's another story.

Live long and keep out of it.

Mark

Hello Mark,
I don't understand this attitude
"Live long and keep out of it."
I can understand your concern if this was a
basket weaving group and Mr Amstereo
mentioned his TV problem.

This is an electronics group for technically minded people
with an interest in electronics. I say to Mr Amstereo,
"get stuck into it, try and find out what is wrong with it"
I am sure Mr Amstereo is a grown up who understands
the dangers. He has been posting here for yonks.

I see more danger driving to the local shops than in the
back of a TV set. Watching young kids play on grassed
areas in a park or the beach scares me because of
syringes lying around or buried in the sand. I could
go on to other dangers, drinking, smoking etc, but you
get my drift.

Anyway, Mr Amstereo, check the things suggested
by others, give it a good eyeballing with a magnifying glass,
obtain the circuit if you can and have a bit of fun
searching for the faults and enjoy the satisfaction of fixing
it yourself.

Regards,
John Crighton
Hornsby
Click to expand...
 
yeah bud, I thank you for ou concern. I understand fully the dangers of the
inside of a tele, The flyback tranny, the connections to the actual tube,
the secondary side of the switch mode power supply, and (where existant) the
injuries a charged capacitor can inflict on ones person.

the ELCB's purpose (to me) is to prevent shocks from the primary side of the
switch mode power supply (primary in the iron core tranny reasoning).
ITs only to protect me from the power point side.

poking around inside the unit with a soldering iron touhning up frosties
should help a bit, and whats the worse that could happen? a dead tele? no
biggie, wasn't planning on getting it looked at AGAIN, $400 for a new 68cm
isn't that much considering the warranty you get with it.

This things already cost me about $300 (in repairs) the set cost nothing -
scored it because of a pulsating picture (during high brightness frames) -
after whichn the frame chip went.
 
On Wed, 3 Mar 2004 19:26:33 +1000, "amstereo"
<amstereo@optushomeDOTcompanyDOTaustralia> wrote:

Hi,
Got a older akai (~6 - 8 yrs)

the other day, it started to fade to black then back to normal,

Its like power to the tube is failing - just a guess cause the brightness
goes to complete darkness, and when i press a button on the tele of remote,
the OSD fades as well so it's not the actual brightness control activating
it (i know this cause when youset the brightness level (using the remote)
the picture will fade to black but the OSD is still visible.

any idea what the cause is? i can place the problem back to when the
heatwave was on in brisbane - the actual problem began then and hasn't gone
away. Takes about an hour before the problem starts - then its continuous
until the tele cools down again.

heat related - just where the issue is, i dunno.


agreed on comments on dry joints on tube neck heater pins. USually
Click to expand...
sets have a 5w resistor in the heater circuit as well - often on the
main board. obviously this is another culprit for dry joints.

also check electrolytics generally - these AKAI ones tend to fail and
produce strange faults.

Power supply would be a good starting point.
 
john_c@tpg.com.au (John Crighton) wrote in message news:<4046cae4.7845187@News.individual.net>...
On 3 Mar 2004 14:55:07 -0800, mvandere@iprimus.com.au (Mark van der
Eynden) wrote:

"amstereo" <amstereo@optushomeDOTcompanyDOTaustralia> wrote in message news:<4045cf48$0$14970$afc38c87@news.optusnet.com.au>...

Hello Mark,
I don't understand this attitude
"Live long and keep out of it."
I can understand your concern if this was a
basket weaving group and Mr Amstereo
mentioned his TV problem.
Click to expand...
John,

I am fairly certain, from his previous posts in this forum, that Mr
Amstereo has a reasonable idea of the dangers involved in mucking
around inside a TV. However, I felt the inaccuracies in the
information contained warranted a comment for the casual searcher who
comes to this particular thread looking for a cure to his TV problem.

Mark
 
too true, anything with mains connections or big capacitors can easily give
you a good beating/death meating. Youngsters and those who are thinking
about touching stuff like this, REMEMBER - its your funeral, tred
carefully - if the set is powered up always keep a hand behind your back. if
you get belted in one arm, its less likely to stop your heart, If your
hearth stops, (and theres no one around) your as good as dead.

Play it safe, Stick to 12V
 
On Thu, 04 Mar 2004 09:05:35 GMT, john_c@tpg.com.au (John Crighton)
wrote:

This is an electronics group for technically minded people
with an interest in electronics. I say to Mr Amstereo,
Click to expand...
And people who don't know what an elcb is for or how it is designed to
work.
 
<David Sauer> wrote

This is an electronics group for technically minded people
with an interest in electronics. I say to Mr Amstereo,
Click to expand...
And people who don't know what an elcb is for or how it is designed to
work.


*** Er,not suprising as the equipment in question has not been referred
to as elcbs for many years.
They are now RCDs (Residual Current Devices).

Brian Goldsmith.
 
Hi, thank for the pointers, I ran round the board attached to the neck of
the tube with a soldering iron, and, It is now perfecto. I'm impressed,
saved me a trip down to the repair guy.

And the only casualty out of the whole job?
The front power LED (3mm oldschool red) Which doesn't bother me any. I'll
just replace it with a blue or white one. Just to be different.

Thanks again guys.
 
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