Panasonic MX10A ch. - Grey onscreen display.

[rg26ce1991@hotmail.com]

Greetings group.
I have a Panasonic ctv model TX-68X02A (MX10A chassis) with a random
fault.

The onscreen display sometimes looses colour, everything displays in
grey. At the same time, the tv station program and AV program picture
seems to increase in brightness, but it still has colour.
The brightness/contrast controls do not return the picture to normal.

One time, it did stop showing a off air picture completely.

When no station is tuned, the screen should be blue, but when the fault
is present, the screen is grey.

The picture can sometimes also reduce in height.
And at times, all the stations have been lost.

All caps have been tested with an ESR meter.
I first suspected a dry joint, but vibration does not seem to have any
effect.

I have a copy of the schematic.
All settings in the "Market Mode" are o.k.

Can anyone please assist?

Thanks,
Russell Griffiths.

 

[rg26ce1991@hotmail.com]

Problem fixed.
Thankyou to Silicon Magazine and the "Serviceman".
He tells a very similar story in 09/05 issue.

The faulty part is IC884 PQ05RD1B 5Volt regulator.

The output voltage was varying, sometimes it was under 5v,
sometimes it was up to 7v.

Russell Griffiths.