atari 400 Help me! I’m stuck! Atari 400 repair

[eegad]

This is what happened with my 400 when it stopped working.... Sometimes a black screen,  sometimes a green screen,  once or twice even a dark red screen.  Turned out to be a bad ram card.  I think i paid around $15 for a replacement on ebay.  Swapped the ram card and the 400 booted up fine. 

 

[Jonny swanny]

Ok, Update, just got the new RAM board in the mail, no help.  but when testing (and only with Star Raiders) I managed to get this screen. Any thoughts?

 

EDIT: I only managed to get this screen to appear twice

Edited October 20, 2020 by Jonny swanny

[+kheller2]

I'm bumping this thread for two reasons:

1) To see if any progress has been made on this wonderful 400 and 

2) I finally, finally own a 400!  It looks pretty dirty and beat up, not exactly as bad as the one in this thread but I hope to do it justice in restoring it. It was listed for parts.  I'll be going through a restoration and posting about it over the next few weeks.  So what do people use to attach the metal door shield when the foam is dust... and does anyone have a 400 door spring?  I might be able to restore this one but.. its pretty jacked.

[Paul Westphal]

It's either the GTIA,  ANTIC, or PIA in that order. You can either buy a new CPU card, or just the chips. I'd buy a new CPU card, then take out the old chips out of the old CPU card and test them individually, then toss the bad one. Extra chips for the future!

Eightbitfix.com

Edited December 20, 2020 by Paul Westphal

[+bob1200xl]

If you put up pictures of the cards, I will look for some that you can use.

 

Bob

 

[Jonny swanny]

It is fixed, and I can explain it all in the morning. it’s currently 22:30 (10:30 pm) where I live. As for the door spring, I replaced mine with one from an Atari 2600 cartridge with the legs cut down. It was a ROM chip. Not RAM, not CPU.  good luck!

[rchennau]

On 12/19/2020 at 8:31 PM, Jonny swanny said:

It is fixed, and I can explain it all in the morning. it’s currently 22:30 (10:30 pm) where I live. As for the door spring, I replaced mine with one from an Atari 2600 cartridge with the legs cut down. It was a ROM chip. Not RAM, not CPU.  good luck!

Please update with what you did to fix.  I have an Atari 400 that boots

to green screen 90% of the time.  I’ve swapped everything and am about to swap the power board to eliminate power issues. 

[Jonny swanny]

2 hours ago, rchennau said:

Please update with what you did to fix.  I have an Atari 400 that boots

to green screen 90% of the time.  I’ve swapped everything and am about to swap the power board to eliminate power issues. 

Second time writing this because I was stupid and accidentally deleted it all... anyways I keep it (relatively) brief.
 

I bought an untested machine for $20, swapped parts, and it was one of the ROM chips.
 

Unfortunately, I cannot remember which one it was, but it was certainly either A103, A104, or A105 below and to the left of the cartridge port. Ill look at my spare parts to see if I left out the bad part and can let you know the exact specs, but I probably stuck it back in my parts machine which is now unaccessible.

 

Keep in mind however, that this was just my fix, from my understanding, a green screen, from what Ive learned about it, can be caused by any number of different issues.

 

Have you tried using a different RAM board? Thats probably the most easy possibility on the wallet.

 

Good luck my man!

[rchennau]

4 hours ago, Jonny swanny said:

Second time writing this because I was stupid and accidentally deleted it all... anyways I keep it (relatively) brief.
 

I bought an untested machine for $20, swapped parts, and it was one of the ROM chips.
 

Unfortunately, I cannot remember which one it was, but it was certainly either A103, A104, or A105 below and to the left of the cartridge port. Ill look at my spare parts to see if I left out the bad part and can let you know the exact specs, but I probably stuck it back in my parts machine which is now unaccessible.

 

Keep in mind however, that this was just my fix, from my understanding, a green screen, from what Ive learned about it, can be caused by any number of different issues.

 

Have you tried using a different RAM board? Thats probably the most easy possibility on the wallet.

 

Good luck my man!

I swapped everything out except the main board.  I was about to give up in despair but I had one last idea.  What if the Atari power supply was bad?  Dig out another one I had and it works.  Boots consistently every time.  So you are right the color screens can be caused by a  number of things.  In this case it was a bad PSU.  
 

Now I have an Atari 400 with a UAV and a 48/52 RAM card paired with my FujiNet!