800XL - B&W output:

[Muzz73]

Hello all!

 

My 800XL has recently gone to B&W output only and I was wondering if anyone could give me some pointers.

 

First, I have tried different monitor cables with no luck.

 

Next, I tried a spare motherboard with said cables and got a full color output without any problems. I'd still like to get this other one working at 100% functionality if I'm going to put it away as a spare.

 

Disclaimer - I have no appreciable knowledge of electronics and am not particularly skilled with a soldering iron.

 

Before I begin switching GTIA's around, can anyone tell me if there is something else I should be looking out for?

 

Many thanks in advance!

 

Louis

[tjlazer]

Try moving the potentiometer on the bottom of the case. Sometimes those need to be readjusted.

[Muzz73]

Many thanks! I'll give it a go tonight!

[+DrVenkman]

Hello all!

 

My 800XL has recently gone to B&W output only and I was wondering if anyone could give me some pointers.

 

First, I have tried different monitor cables with no luck.

 

Next, I tried a spare motherboard with said cables and got a full color output without any problems. I'd still like to get this other one working at 100% functionality if I'm going to put it away as a spare.

 

Disclaimer - I have no appreciable knowledge of electronics and am not particularly skilled with a soldering iron.

 

Before I begin switching GTIA's around, can anyone tell me if there is something else I should be looking out for?

 

Many thanks in advance!

 

Louis

 

Look at the tiny capacitor the left and slightly below (to the front) of the 4050. I had one leak and it resulted in a black and white image. If that looks okay, try swapping the 4050 hex buffer chip. The video signals from the GTIA all go there on their way out the system to the RF modulator and video jack. If one of the internal buffer circuits in the IC goes bad, it might be depriving the output signal of Chroma, resulting in a monochrome image.