Trouble shooting an Atari 800. Powers up to blank blue screen.

[auto_cran]

Like the title says. Acquired an Atari 800. After cleaning it up, I plugged it into an old monitor - and all I get it s a blue screen. No Memo Pad. If I press the keys, nothing appears on the screen. The System Reset key (top right) seems to work as the screen flashes when I press it.

 

I have a few game cartridges (no BASIC) and when I turn on the 800 with one plugged in, it works fine (and the Options and Start keys work fine).

 

I also have an Atari 400 - and that seems to boot up to Memo Pad just fine.

 

Any ideas what's wrong with the 800? I'm not too familar with these Ataris.

 

thanks!

 

Chris

[RickR]

Take the top cover off. The first slot should have a 10K ROM card. I'd try pulling that out, gently cleaning the contacts with a rubber eraser, and then put it back.

[auto_cran]

Thanks Rick. Just tried it per your suggestion. I even took all the memory cartrs out and cleaned them. No luck. Same results.

 

Let me add a few more things...

 

When I turn on the power (or hit the System Reset button), it makes the "click" noise, which I assume is normal.

 

The screen looks great - nice clear blue with the cursor at the very top left corner. Nothing else. No words, nothing. Typing does nothing.

 

I don't have the BASIC cart, but I do have the AtariWriter cart - and when I power on the A800 with it inserted, I get the nice logo, but that's it - I can't get past that screen.

 

I'm starting to wonder if there is an issue with the keyboard???

 

Thanks in advance

 

Chris

[Rybags]

Keyboard will make no difference, it should have the Memo Pad text without a cart installed.

 

Try running with just 1 memory module in the frontmost slot, try each one in turn.

 

Chances are though it's a dodgy OS module, next up you might try opening it up then gently pry up the large chips and reseat them.

You don't have to pull them out, just levering up each side by about 1 mm is usually enough.

[RickR]

I doubt it's the keyboard. Probably one of the chips within. CTIA/GTIA most likely. Hopefully someone with more experience will chime in here to help. You'll probably want to open up the case and press down on all the socketed chips (just to make sure they are seated). But that is kind of a pain with the 800, as you have to take it apart quite a bit to get that far. Like I said, I hope an expert here has a better idea of what exactly it could be.

[Joey Z]

Thanks Rick. Just tried it per your suggestion. I even took all the memory cartrs out and cleaned them. No luck. Same results.

 

Let me add a few more things...

 

When I turn on the power (or hit the System Reset button), it makes the "click" noise, which I assume is normal.

 

The screen looks great - nice clear blue with the cursor at the very top left corner. Nothing else. No words, nothing. Typing does nothing.

 

I don't have the BASIC cart, but I do have the AtariWriter cart - and when I power on the A800 with it inserted, I get the nice logo, but that's it - I can't get past that screen.

 

I'm starting to wonder if there is an issue with the keyboard???

 

Thanks in advance

 

Chris

if it were the keyboard (alone) then the 'atari - memopad' message should still appear on the screen. chances are that the problem(s) lies elsewhere. (although that doesn't mean there aren't keyboard issues). I would try (if you are confident enough) to swap the OS ROMs out of the 400 and into the 800 (or vice versa) to see if anything changes. if you would like to try this, I could go into more detail with the process since the 400 and 800 differ a little in how they are setup internally and the positions of the ROMs themselves.

 

EDIT: and agreed with the others, you should try reseating various chips before you try that.

Edited December 10, 2013 by Joey Z

[Bryan]

The good news: It's partially working. You don't get to a blue screen with a cursor unless the OS has been running for a bit.

 

The bad news: Something is obviously wrong and the system is crashing. This is probably a good candidate for a diagnostic cart, though.

[ClausB]

I had one with the same symptoms, except that I had unplugged the speaker, so I didn't hear the cassette boot buzz. The START button was stuck on, so it was sitting at the blue screen waiting for the cassette boot. It turned out to be a faulty CTIA, but only its switch inputs. I replaced it with a spare GTIA and all was fine. Too bad, I really wanted a CTIA 800.

 

The speaker is driven by the same GTIA switch port, so if you don't hear the buzz, maybe your whole port is bad.

 

[auto_cran]

Thanks for all the tips!

 

This weekend I'll see about opening up the case and checking the chips and attempt to reseat them.

 

Once again, thanks - and I'll report back my findings/results.

 

Chris

[Rybags]

The OS chips I mentioned are on the 10K "Operating System" board - only need to open top cover to get to that.

 

Stuck Start key sounds feasible although that would affect games. You might want to try turning on and press a few keys after a couple of seconds.

 

If it's stuck start key then once a keypress gets registered, a BOOT ERROR should show up after about 30 seconds.

[auto_cran]

Quick update - opened up the 10K Operating System cart and reseated the chips in there (thanks for clarifying, Rybags) and cleaned the contacts better since having better access. Then once installed, I tried running it with just 1 memory cart. Same thing - no luck. Then I tried swapping memory carts / inserting them in different slots. Same thing. The only difference I noticed is if I didn't have a memory cart in the slot next to the OS cart( ie - OS cart, empty slot, memory cart) - I got nothing - no blue screen. I also tried just keeping it on for a few minutes to see if any error would appear. Nothing - just the blue screen with the solid cursor.... When I get more time I'll open it up and take a peek inside.

 

On a better note, included with the 800 was a 130XE - and it appears to be working fine - turning on to BASIC (although it scared me - when I first tried it, I got the same blue screen as the 800 - but after a few seconds it goes to the Ready prompt).

 

With the 130XE, I now have (working) an A400, A600XL, A800XL and now the A130XE. Hopefully I can get that A800 working!

 

thanks again

 

Chris

[SignGuy81]

http://atariage.com/forums/topic/271142-xegs-blue-screen-of-death-fixable/