Fried an Atari 800

[JonnyBritish]

Evening

 

This evening i decided to open up a working Atari 800 to see how it was put together and to see how to swap out the keyboard with a new one i bought. Sounds easy huh and indeed i thought it was until i put it all back together and now only get a green screen with no text. I have rechecked everything and all connectors are in place etc. Sort of thinking I may have blown a chip somewhere. Any thoughts on what to do to fix this or troubleshoot? Would a SALT II cartridge help identify failure?

 

After this experience I will leave my working 800xl and 130xe well alone :-)

[Rybags]

A Diag cartridge might provoke a different reaction... Star Raiders runs as one so you could try it if you have one.

 

Maybe try it again with the top shielding off... try with only first RAM slot occupied, try turning off and reseating the CPU board, OS board etc.

[the.golden.ax]

Hmn... fried it and then put salt on it... sounds like you need some toast and orange juice to make it part of this complete breakfast.

 

AX

[MEtalGuy66]

You didn't fry it..

 

Atari chips are TOUGH... unless you overvoltaged it, you didn't fry it..

 

Check all your plug-in cards.. make sure the contacts are clean, and the cards are socketed correctly.

 

Alot of those cards on the 800s exhibit some "manufacturing shift".. In otherwords, the allignment isnt perfect on the contacts.. You may experiment with loosening mounting screws and shifting stuff slightly left or right until the cards plug in easily..

 

If you didn't take any chips out of their sockets, and the thing was working before, it will work again.. You've just got an assembly issue and for some reason, the thing has an open circuit (or bad connection) somewhere on the bus.. Just be patient and play around with it.. you'll get it going again..

[JonnyBritish]

A Diag cartridge might provoke a different reaction... Star Raiders runs as one so you could try it if you have one.

 

Maybe try it again with the top shielding off... try with only first RAM slot occupied, try turning off and reseating the CPU board, OS board etc.

 

What do you mean star raiders runs as one? I have star raiders

[JonnyBritish]

Also noticed when i firststart the computer the screen is blue but then after a minute or two its green. need to read the service manual

[atariksi]

Also noticed when i firststart the computer the screen is blue but then after a minute or two its green. need to read the service manual

 

I once had a blue screen (with cursor in UL) on A400 and then it would turn black/brown on boot up. I found out it was the POKEY chip that was bad. I replaced it from an A5200 and it's been working since then. (A400 is similar to A800.)

[Rybags]

"Diag cartridges" means they have the relevant flag set so they get almost immediate control.

 

Some games run as such - they can come in handy for testing dodgy machines if the Operating System ROM/s are somehow partially corrupted to the point that the machine starts up to a point but then crashes because the ROM isn't being read properly.

 

Diag carts bypass most of the startup process, so you'll often get a different looking screen - in all likelyhood it'll still crash but it can help with the process of working out what part of the machine isn't working properly.