Hitachi TV Takes 10 Minutes to Work !
 

I have a Hitachi colour tv which is 20+ years old, it is not a "warm
up" tv, it usually switches on immediately.

Just recently, when switching it on it has a very thin horizontal line,
the rest of the screen remaining black.

After leaving it on for about 10 minutes the whole picture immediately
reappears. Sound is unaffected.

Would anyone have any ideas as to what might be wrong...?

"Mike" wrote in message
ups.com...

I have a Hitachi colour tv which is 20+ years old, it is not a "warm
up" tv, it usually switches on immediately.

Just recently, when switching it on it has a very thin horizontal line,
the rest of the screen remaining black.

After leaving it on for about 10 minutes the whole picture immediately
reappears. Sound is unaffected.

Would anyone have any ideas as to what might be wrong...?

Apart from the line now burned into the screen?

N

Mike wrote:

I have a Hitachi colour tv which is 20+ years old, it is not a "warm
up" tv, it usually switches on immediately.

Just recently, when switching it on it has a very thin horizontal line,
the rest of the screen remaining black.

After leaving it on for about 10 minutes the whole picture immediately
reappears. Sound is unaffected.

Would anyone have any ideas as to what might be wrong...?

vertical output section
check for solder joint cracks
around the vertical section.
also, spraying component cooler
on said components after which
the TV has started to work may
help in finding a bad semiconductor.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Thanks Jamie!

I'll check for that... thanks

The line does not appear to have burned into the screen. It's just a
thin line of white light. Though you can see movement in the light, as
if the tv picture is still being shown on the thin horizontal line.

Though as the line is so thin, it's not possible to see any picture,
just the movement of the light.

Once the picture reappears after 10 minutes, there is no line visible.
The picture is normal.

On 10 Jul 2005 04:20:18 -0700, "Mike"
wrote:

Thanks Jamie!

I'll check for that... thanks

As long as you continue to use it that way, turn the brightness down
every time before shutting it off. If it is digital on-screen menu
controls you'll have to remember how many key strokes to get to
brightness.

Tom

"Mike" wrote in message
ups.com...
The line does not appear to have burned into the screen. It's just a
thin line of white light. Though you can see movement in the light, as
if the tv picture is still being shown on the thin horizontal line.

Though as the line is so thin, it's not possible to see any picture,
just the movement of the light.

Once the picture reappears after 10 minutes, there is no line visible.
The picture is normal.


It'll burn into the phosphor pretty quickly if you use it like that, I would
recommend unplugging the set immediately until the fault has been repaired,
it's a simple fix so far.

Thanks Tom,

no there's no on-screen menu as the tv is over 20 years old. No remote
control either...

Shows how good Hitachi tv's are, as it's never given any problems
before!

Is there any easy way of knowing where the vertical output section is?
I took the back off the tv, and was hoping it would be marked "vertical
output", but it doesn't appear to be...

It's a Hitachi CPT 2224

There's a small circuit board attached to the very centre of the back
of the screen, there's two solder joints that look as if there's a hole
going through them. They're marked GND and K1.

Thanks!

Hello, Mike!
You wrote on 11 Jul 2005 04:40:13 -0700:

M It's a Hitachi CPT 2224

M There's a small circuit board attached to the very centre of the back
M of the screen, there's two solder joints that look as if there's a hole
M going through them. They're marked GND and K1.

Don't think that's it Mike, your looking at the CRT pins. The vertical
oscillator section will be on the mainboard. I don't really recommend you
try to fix this yourself, as you really need access to the solder side of
the main chassis, and there are potential (no pun intended) problems
concerning dismantling reassembly and safety that call for a bit of
experience. Take it to a repair shop, at this point the repair is likely to
be an easy one, but an inexperienced repairer could soon fix that. :^)
Best of luck.



With best regards, 3T39. E-mail:

Thanks 3T39

I was about to contact a repair shop, when I managed to find the
vertical section on the motherboard.

I gave it a clean with a cotton bud, as it was thick with dust. The
tv's over 20 years old.

Anyhow, it seems to be working now...!

It was mentioned above about spraying component cooler on the
components after the TV has started to work which may help in finding a
bad semiconductor.

Out of curiosity, what is this component cooler? Is it something like
WD40? Or something completely different?

Mike ha escrito:
Thanks 3T39

I was about to contact a repair shop, when I managed to find the
vertical section on the motherboard.

I gave it a clean with a cotton bud, as it was thick with dust. The
tv's over 20 years old.

Anyhow, it seems to be working now...!

There is no way on earth that dusting the set will bring about a repair
to this sort of problem. You have treated the symptom not the cause. If
you are serious about getting this eert working `properly, *Take the
advice given you and get the set in to a tech who will do the necessary
simple soldering*.
-B.

Mike wrote:
Thanks 3T39

I was about to contact a repair shop, when I managed to find the
vertical section on the motherboard.

I gave it a clean with a cotton bud, as it was thick with dust. The
tv's over 20 years old.

Anyhow, it seems to be working now...!

There is no way on earth that dusting the set will bring about a repair
to this sort of problem. You have treated the symptom not the cause. If
you are serious about getting this unit working properly, *Take the
advice given you and get the set in to a tech who will do the necessary
simple soldering*. It sounds like you may be out of your depth here.
-B.

Hello, Mike!
You wrote on 11 Jul 2005 07:58:10 -0700:

M I was about to contact a repair shop, when I managed to find the
M vertical section on the motherboard.

M I gave it a clean with a cotton bud, as it was thick with dust. The
M tv's over 20 years old.

M Anyhow, it seems to be working now...!

M It was mentioned above about spraying component cooler on the
M components after the TV has started to work which may help in finding a
M bad semiconductor.
Out of curiosity, what is this component cooler? Is it something like
WD40? Or something completely different?


It's possible that your probing with a cotton bud has moved the faulty joint
and caused it to connect a little better, but I'm in no doubt It's still
there. I say joint, because reading your posts, I think on balance it's a
little more likely to be a bad, thermal sensitive, joint than a faulty
component. But of course I could be wrong here. It's the solder side of
this mainboard around the vertical oscillator that you need the magnifier,
reflow any bad or cracked joints. Concentrate on the items that use most
power ( big stuff, and anything fastened to a lump of aluminum) as these
will fail first. The cooler mentioned earlier is basically a chemical with a
very rapid evaporation rate in a spray can, so when a component is sprayed
the evaporation carries away huge chunks of heat.

With best regards, 3T39. E-mail:

Hello, 3T39!
You wrote to Mike on Tue, 12 Jul 2005 14:10:36 +0100:

M I was about to contact a repair shop, when I managed to find the
M vertical section on the motherboard.

M I gave it a clean with a cotton bud, as it was thick with dust. The
M tv's over 20 years old.

M Anyhow, it seems to be working now...!

M It was mentioned above about spraying component cooler on the
M components after the TV has started to work which may help in finding a
M bad semiconductor.
T Out of curiosity, what is this component cooler? Is it something like
T WD40? Or something completely different?

T It's possible that your probing with a cotton bud has moved the faulty
T joint and caused it to connect a little better, but I'm in no doubt It's
T still there. I say joint, because reading your posts, I think on balance
T it's a little more likely to be a bad, thermal sensitive, joint than a
T faulty component. But of course I could be wrong here. It's the solder
T side of this mainboard around the vertical oscillator that you need the
T magnifier, reflow any bad or cracked joints. Concentrate on the items
T that use most power ( big stuff, and anything fastened to a lump of
T aluminum) as these will fail first. The cooler mentioned earlier is
T basically a chemical with a very rapid evaporation rate in a spray can,
T so when a component is sprayed the evaporation carries away huge chunks
T of heat.

Meant to mention as well, there four coloured, fairly heavy wires going to
the scan coils which plug into a socket on the mainboard. check the joints
of the socket

With best regards, 3T39. E-mail:

Ok thanks very much for the info 3T39. Much appreciated!

I'll take it apart again and have a check for that. The tv has been
working away ever since with no problems...!

Thanks again.

M It was mentioned above about spraying component cooler on the
M components after the TV has started to work which may help in finding
a
M bad semiconductor.
Out of curiosity, what is this component cooler? Is it something like
WD40? Or something completely different?



It's refrigerant, used to be R-12 Freon, now it's R-134.

"James Sweet" wrote in message
news:Nl%Ae.12458$Ll6.9924@trnddc06...

It's refrigerant, used to be R-12 Freon, now it's R-134.

Sure it's not a butane type product? What does the label say about
flammability?

N

Sure it's not a butane type product? What does the label say about
flammability?



The can I have says Contains Tetrafluoroethane, that's R-134a. It doesn't
explicitly say that it's pure R-134 but I'm sure if it contained butane it
would say so. Of course it's possible that the substance in the can varies
by brand, I dunno.