Old style telly (tube), colour gone a pink hue!

Betsy Og

anyone had this before (yes, yes, I know you havent had a telly like that in a decade or so), and if so was it terminal??

Dave_Dublin

Was there a magnet near it ???


I did that to my parents TV years ago when I noticed a magnet sticks to the screen . . .

Only thing was, the colour went pink / green for a few weeks in the spot where I put the magnet -- corrected itself gradually.

( I was only 5 or 6 at the time )

Ronnie Raygun

If you're watching via a separate receiver using a scart lead, check the connections.

Sam Russell

Also, if it is not the scart, then turn the set off at the mains and back on a few times, leaving it on for several minutes, like 15, each time. This will cause the degause circuit to work which will eventually demagnetise the screen.

The phosphors become magnetised over time which changes the colour they give off, and so CRT TVs have a circuit to demagnetise the screen. This circuit operates for a few seconds when the TV is powered on.

tadgh

Had this problem with a 28" CRT TV before. The DeGauss wasn't working.
Solved it by holding an old CRT computer monitor adjacent to TV (TV switched on) & switching on the monitor.
Repeat if necessary until normal colours achieved.

BostonB

tadgh wrote: »

Had this problem with a 28" CRT TV before. The DeGauss wasn't working.
Solved it by holding an old CRT computer monitor adjacent to TV (TV switched on) & switching on the monitor.
Repeat if necessary until normal colours achieved.

Can you you explain how that worked?

winston_1

Most probably the green RGB driver circuit. Could be the driver transistor or the adjustment pot gone dodgy.

tadgh

BostonB wrote: »

Can you you explain how that worked?

The DeGauss from the CRT monitor is transmitted to the TV (If it is held close to the telly)

Frynge

tadgh wrote: »

The DeGauss from the CRT monitor is transmitted to the TV (If it is held close to the telly)

Quite frankly, that is genius.

Antenna

Sam Russell wrote: »

The phosphors become magnetised over time which changes the colour they give off, and so CRT TVs have a circuit to demagnetise the screen. This circuit operates for a few seconds when the TV is powered on.

Phosphors do not get magnetised,
It is the shadow mask (metal plate with lots of holes behind the front of the screen) present in colour CRTs that does

http://en.wikipedia.org/wiki/Cathode_ray_tube

**
BTW failure of the degauss in the TV wouldn't lead to the whole screen being evenly affected by the above problem, it would be uneven . It's an electronic problem as Winston_1 suggests.

Betsy Og

Folks, I'm seriously impressed, I didnt really think anyone would have seen this before/that it could be solveable.

Must try out these cures tonight.

Thanks for all your help.:)