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Hopefully a simple TV repair fix

K

Kash

Jan 1, 1970
0
Hi

I have a Goodmans 205N TV with CP-775 board. I have moved from the UK
to Australia and unfortunately found that I could only get picture and
no proper sound when connecting my UK TV to the Australian system (UK
is PAL-I and Aust PAL-B/G).

I thought there might be a switch or something obvious that I could
replace to fix the problem so I opened up the TV and took the board
out. Unfortunately I found nothing. I then read a post somewhere else
that worked around this problem by connecting an Austrlian Video
player via a SCART to the TV. I then reconnected the board back into
the TV and switched it on. Everything started as normal except I now
get no picture. Just a blank tube. However sound plays and functions
like channel up etc all work. I can tell that I am changing channels
because there's a pauise and then static agsin :)

Any ideas??? One of the areas I looked at was the connector to the
back of the tube via a sucker. What's that for and can it be causing
the problem (i.e. incorrect re-connection).

Alternatively if you have a time machine ...

Cheers
Kash
 
A

Arthur Jernberg

Jan 1, 1970
0
Suction Cup thingy is the insulator for the hv connection: in the centre of
the suction cup is a metal connector that must be placed within the divit on
the picture tube otherwise the hv will not conduct properly to the inside of
the tube and you may have and arc generated or even a shutdown. Also the
neck of the picture tube contains elements that also have filaments within
it, when in operation the filaments will glow a warm red colour indicating
that ther is curent at least getting to that area of the tube. Without
having these 2 important facets operational you will have a dark screen.
Have another go at it but leave the Fosters alone until done, Cheers
 
K

Kash

Jan 1, 1970
0
ok Fosters is back in the fridge.

I've tried the suction thing back on with teh connectors in teh divit
and no joy. However teh filament is not glowing. Could the filament
have got damaged (even though I didn't touch it, just removed the
board from it) or something else?

Cheers
Kash
 
A

Arthur Jernberg

Jan 1, 1970
0
Loss of filament may be caused by lack of horiz output from the main board.
The horiz circuit must be operational including the hv section to produce
the required currents to make the crt function. Having the function
previously I'd suspect probably a poor connection or even a cracked circuit
board. Recheck all the connections from the main to the crt neck board on
the rear of the crt. Sounds as if you may need to have a tech have a go at
your tele.Cheers
 
B

Borg

Jan 1, 1970
0
That suction cup thingy can have up to about 27000 volts behind it even when
the TV is off so you might want to discharge the tube first
 
T

TV Fixer1

Jan 1, 1970
0
don't overlook the possibility you've bent one of the CRT pins, and it's not
seated in the socket correctly; beer will cause this.
 
R

Roy J. Tellason

Jan 1, 1970
0
TV said:
don't overlook the possibility you've bent one of the CRT pins, and it's
not seated in the socket correctly; beer will cause this.

Heh, this reminds me of one (now gone) tv repair shop I worked at for a
short time, the soda machine had a button labeled "out of order" but
selecting that one after putting your money in got you a can of beer. I
never saw such a byzantine setup for which portions of doing things was
allocated to who, and I think the only person in the place who made any
money was the gofer...

My biggest problem there was a great dane (named "yagi") that had some sort
of a digestive problem that gave it gas. Kinda hard to deal with...
 
F

Franc Zabkar

Jan 1, 1970
0
I have a Goodmans 205N TV with CP-775 board. I have moved from the UK
to Australia and unfortunately found that I could only get picture and
no proper sound when connecting my UK TV to the Australian system (UK
is PAL-I and Aust PAL-B/G).

If you ever get picture again, then you may need to change all the
6.5MHz (?) parts in the IF stage to 5.5MHz. That's the difference in
frequency between the sound and vision carriers for the UK and
Australia.


- Franc Zabkar
 
K

Kash

Jan 1, 1970
0
All fixed :)

I took it to a repairer and after a bit of fiddling and Umming he
asked me if I had touched some screws at the side of the board. I had.
They turned out to be voltage setters for the tube. A quick turn and
my picture came back.

He also pointed out that he was surprised I hadn;t been flung across
the room when disconnecting the suction thingy. so moral of the story
always earth yourself to a fosters when working on high voltage items
;-)

PS. Sound cannot be sorted as it's Nicam TV and it's on a chip.
However I've just purchased an Ozzy video player which will input via
Scart to the TV to give sound and vision.

Thanks everyone.
 
A

Art

Jan 1, 1970
0
IMHO if one is ignorant per specific service procedures it may be best to
have more than one investigate failure and repair modes, preferably the
other being a certified tech. Glad tele is rectifiec for your use. Cheers
 
A

Andre

Jan 1, 1970
0
All fixed :)

I took it to a repairer and after a bit of fiddling and Umming he
asked me if I had touched some screws at the side of the board. I had.
They turned out to be voltage setters for the tube. A quick turn and
my picture came back.

He also pointed out that he was surprised I hadn;t been flung across
the room when disconnecting the suction thingy. so moral of the story
always earth yourself to a fosters when working on high voltage items
;-)

PS. Sound cannot be sorted as it's Nicam TV and it's on a chip.
However I've just purchased an Ozzy video player which will input via
Scart to the TV to give sound and vision.

Hmm - the chip's probably fried. Those things are easy enough to
repair if you know how, Telepart (www.telepart.co.uk) do nearly every
video and TV IC known to man.

I've had the best success by using solder wick on all the pins then
installing a socket (you really don't want to lift tracks if the chip
fails again) - this is always advisable with any unit where practical.

I might have a NICAM chip someplace, please post the chip's part
number.

-A
 
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