Cleaning an Atari 800XL

[doncleth]

Hi all,

 

I bought this 800XL advertised in eBay as non-working . After vacuuming the insides and re-attaching the cable from the keyboard, it suddenly worked!

 

Anyways, I still have a couple of problems:

 

First, some of the keys are sticky and no matter how many times or how hard I press them, they don't register on the screen. How do you fix this?

 

Secondly, the metal cover that covers up the ICs and the circuit board have signs of rusting. Is it still possible to revive this like sanding it and repainting it?

 

Also the red LED doesn't light up. But that's not a big deal.

 

Any tips like DOs and DONTs will be appreciated.

 

TIA,

Don

[bjk7382]

First, some of the keys are sticky and no matter how many times or how hard I press them, they don't register on the screen. How do you fix this?

 

When you open it up you need to make sure to get the ribbon cable for the keyboard all the way down in the connector.

 

Secondly, the metal cover that covers up the ICs and the circuit board have signs of rusting. Is it still possible to revive this like sanding it and repainting it?

 

you shouldn't have any problems sanding and repainting it

 

Also the red LED doesn't light up. But that's not a big deal.

measure the output on the two legs of the led and go to radio shack and pick one up that is the same voltage and solder it in place.

[Bryan]

First, some of the keys are sticky and no matter how many times or how hard I press them, they don't register on the screen. How do you fix this?

 

It depends. There are at least 5 different keyboards used in the 800XL. Sometimes they can be fixed, and sometimes they need new parts. Does this one use a clear plastic ribbon connector with painted on conductors, or something with real wires in it.

 

Secondly, the metal cover that covers up the ICs and the circuit board have signs of rusting. Is it still possible to revive this like sanding it and repainting it?

 

Also the red LED doesn't light up. But that's not a big deal.

 

Don't worry too much about the rust (it won't hurt). Sanding/Painting will take care of the cosmetics, just be sure to allow a good ground connection at the crimps/screws.

 

I am now guessing you have a keyboard with a plastic membrane (the LED connection often goes out in these). You can try removing the back and cleaning the plastic sheet, but you'll probably need to order a new one, as the conductive paint doesn't last forever.

 

-Bry

[doncleth]

Hi Bry,

 

My keyboard connector has the clear plastic ribbon connector with painted on conductors. I will try to push it all the way tonight like what bjk7382 suggested.

 

I opened the back of the keyboard (by removing the small screws) and it has the plastic sheet with all the connectors in there. How does it work anyway? The plastic sheet is folded into two then the spring pushes one side to the other sheet and that causes a signal to be sent? I will try re-opening it again, give it a more thorough clean (I would assume a damp cloth is OK with the plastic sheet?).

 

I will probably work on the rust once I'm happy that all the keys are working.

 

Thanks for the fast replies,

Don

[Bryan]

Yes, the contact on the top sheet is pressed into the one on the bottom sheet by a spring under the key. These traces are originally white, but turn a nasty gray/black as they oxidize. You can gently use a pencil eraser to polish areas that need to make contact (the insertion edge, flaky keys, and the LED contact squares). If that doesn't work, Best Electronics sells the sheet for (hold on...) well, it says "CALL". The best long term solution is to get a better keyboard. There were ones made by Mitsumi and Alps that used a circuit board instead of Mylar sheets. The Alps is the best in my opinion and is easy to spot because the lettering on the keys is so small.

 

Here are some pics:

 

The one with the brown/orange circuit board is the Alps model. The one with the green circuit board is the Mitsumi, and then there's a mylar one (not sure who makes it).

 

-Bry

[doncleth]

Thanks Bry.

 

The keyboard that I have is the second one (the mylar).

 

I'll give it the eraser treatment soon. If all else fails, I hope that new sheet from Best Electronics is not that expensive. Getting a spare 800XL is a bit tricky if you live in Australia.

 

Cheers,

Don

[Bryan]

Don,

 

How did it turn out?

 

-Bry

[doncleth]

Hi Bry,

 

I got the keybord to work by cutting a strip in the keyboard connector. I noticed one of the strips was broken (maybe from being folded too much).

 

But then my problem when I cut a portion of the connector was it was not long enough to reach the socket so I took a plier to bend the metal (at the edge of the RESET button) a little bit.

 

Now my only problem is the LED not working. Can't seem to find a way to remove it.

 

Also thanks for the tutorial on cleaning an 800XL keyboard.

 

Beleted Merry X-mas!

Don

[deathtrappomegranate]

You should be able to remove it with a pair of snips or a soldering iron.

[Bryan]

Actually the LED just pushes into a couple holes (it's not soldered on the mylar keyboards), but if it's not lighting, there's probably paint-trace damage.

 

Don, I have an extra mylar keyboard I could clean up and send you. If you want it, PM me.

 

-Bry

[doncleth]

Hi Bry,

 

PM sent.

 

Cheers,

Don