Weird problems

[homr836]

Hi everyone.

 

I've recently added an after market power supply for my brother in laws CV. Picture is OK (using rf as I can't find a pal av mod board) and everything seems fine. However, when I play donkey Kong, if I lose a life, the controls don't work and I have to reset to get them working again.

 

Additionally, using the atari adaptor only displays B&W and not colour. The switch makes no difference. I've stripped it open and the board looks pristine so I'm out of ideas.

 

Any suggestions please?

[ChildOfCv]

Did the controls work with the original power supply?  That seems more like a software bug though.  Do you see problems with other games too?

 

Could the Atari module be NTSC?  Is there a crystal on the Atari Module, and a chip near it?  On NTSC boards those places are blank.  Otherwise, just like with the real Atari, there's a pot that adjusts color shifting, and if it's turned down too much or not working at all, you get no color output.

[homr836]

Thanks for the reply.

The controls work fine until you lose a life. The only other game is turbo but that uses the steering wheel which is OK.

I've also noticed that you have to cycle the power switch a few times or change the channel a few times before you get a picture (I've replaced the caps and cleaned the power switch, so I don't know what's happening there).

The atari add on was bought with the console in 1983 and ended up stored in his parents loft until  recently. I did read that there is a pot that might sort the b&w picture.

Thank you for the suggestions.

[ChildOfCv]

Does the console have a channel switch on the back?  If so, then the switch might also need to be cleaned.

[homr836]

It doesn't, no. I wish it was that simple.....

[ChildOfCv]

It might be worth checking if your replacement power supply is doing its job.  Check the voltages at both of those choke coils next to the power switch.  One should be 5V and the other should be 12V.