Atari 600 fault

[Pagger29]

Atariage forum,

 

I have a nice looking Atari 600 which I think has had a hard life at some point.

 

It wasn't doing anything until I bought a new cpu for it.  With this installed in get the output attached... Does anyone have any guidance? It starts with the blue screen, then goes to the yellow

 

The computer itself has everything socketed, however I have no Spares so keen not to have to buy loads!

 

 

[Pagger29]

Is anyone able to help?

 

Thanks, 

[+kheller2]

You used a SALLY CPU right?

Turning it on with OPTION down doesn't take you to self tests?

W/o extra chips, it could be hard to diagnose.

 

[+bob1200xl]

'A hard life' for your system may include a shorted power supply, which puts >8 volts on your m/b. Did it come with a power supply? What does it look like? (picture?)

 

I could send you a m/b with good chips in it, but plugging it into a bad supply would just blow it up.

 

Bob

 

[Sugarland]

Yes test the voltage coming off the PSU. Should be close to 5v. Don't use the 'ingot' power supply. If you don't have a voltage meter just get a USB power adapter cord from The Brewing Academy.  Also reseating all the chips can help and deoxit will remove corrosion. Photos of the motherboard and PSU will help.

[+hloberg]

wow, there are so many things that could be. as every one said, start with the power. the old Atari power supplies had lots of reliability problems. testing can be a problem as you really need to test with a load. be sure you still have +5 with in the machine as it's on. or just replace it with a modern one anyway. they're cheap these days. then things get complicated. it could be a capacitor gone bad. which? best to check them all for bloating or leakage. Capacitors are the next problem area as they tend to wear out. Some people just replace all of them as it's not that expensive. next, check the memory chips. that doesn't look like a memory chip problem, but you never know. lastly the various VLSI chips like GITA and ANTIC.  

[Rybags]

Pic 1 looks like the Self Test background colour.

 

Pic 2 looks like the distortion you can get by building a 320 mode screen that's too tall.

 

But anyway... without proper display you'd want to rely on sounds.  Like do you get a click when it powers on or if you press Reset?  And what does the screen do.