Hi everybody,

First post here so be gentle.

I'm currently busy resurrecting a Teleng TCS... I've very nearly got it working now, but the video signal isn't good enough yet. To be more precise, the vertical hold appears to be wrong on certain colour screens.  Playing the sports game (pong) when the screen is one colour, I can get a good display. When the game number changes (the select button), the screen colour changes - some screens disappear completely as the TV can't sync; other screens the screen flashes horribly as though it can't sync properly but can display.

I'm using a Sony Trinitron 14" which is quite good for old machines. I also tried it on my Sony Bravia TFT and no joy. I tried it using RF out and composite video (disconnect the audio from the audio modulator and stick the video input to the video modulator through an NPN transistor to get the composite), same applies either way.

I've tried twiddling the knob next to the PE1X chip a lot, and it changes the signal but I can't get a good signal. My Acetronic MPU-1000 seems a lot better.

Can anyone suggest anything? I've also changed the two 47uF caps near the video circuitry.

Thanks for any help!

Ian Gledhill