Atari 800XL keyboard issue

[erichenneke]

Did you ever get the conductive paint and give it a try?

Sent from my KB2005 using Tapatalk

[kynikos]

15 minutes ago, erichenneke said:

Did you ever get the conductive paint and give it a try?

Sent from my KB2005 using Tapatalk
 

Just got it in the mail today but haven't had a chance to try it out yet. Hopefully will be able to give it a go this weekend if I can get away from the kids for a bit!

[kynikos]

Well, good news - the conductive paint worked! The top row of keys is now working and everything else seems to be fine. Once I got the keyboard out I could see more of the traces across the whole mylar had turned black, so I thought I was in for a bad time, but it worked with just a bit applied to the ribbon part sticking out. Thanks all for the help! I may order a new mylar as a backup just in case but for now everything seems to be working fine.

 

The only thing I couldn't figure out when putting the computer back together was the metal clip on the rear expansion port. It seems to ride under the RF shield tabs. There are two short screws that seem to not bite into anything. Anyone know how that fits together again?

Edited May 28, 2022 by kynikos

[Beeblebrox]

@kynikos well done re restoring the mylar.

 

Re the shield and pbi guard if you have shielding that doesn't have bolts but screws, in order to secure the guard it needs both the top side and underside parts of the shield if I recall. Bolts go through the underside of the pcb shield, through to the top side shield, and the guard is sandwiched in between.

[kynikos]

1 minute ago, Beeblebrox said:

@kynikos well done re restoring the mylar.

 

Re the shield and pbi guard if you have shielding that doesn't have bolts but screws, in order to secure the guard it needs both the top side and underside parts of the shield if I recall. Bolts go through the underside of the pcb shield, through to the top side shield, and the guard is sandwiched in between.

Thanks, I'll give that a go. They are just short bolts now that I looked at them again.

[Beeblebrox]

21 minutes ago, kynikos said:

Thanks, I'll give that a go. They are just short bolts now that I looked at them again.

@kynikos if there are no nuts and bolt combos involved it will be a set of short bolts/screws (let's call em bolts) with a wide slotted head that bites into the upper shielding from the underside of the pcb through the lower sheild part. (Just make sure the cardboard protector layer is installed between the underside shield and the underside of the pcb to avoid the shield shorting out components of course).

 

The two bolts for the pbi guard pass through the holes in the guard where the guard is placed so it's plate holes are under the top shield plate and pcb if I recall correctly. I am not able to check as away at the mo.

 

BTW its important you put the bolts in the original holes and don't put bolts in the two areas where the pcb is secured to the lower case.  If you do the pcb is pushed up 2-3mm by the bolt head and doesn't align with the lower case ports and connector holes, and stresses the board. 

 

I nearly always leave off the shielding once I've opened up an 800XL. I've a large pile of shields now heh heh. 

 

 

Edited May 28, 2022 by Beeblebrox

[erichenneke]

1 hour ago, kynikos said:

Well, good news - the conductive paint worked! The top row of keys is now working and everything else seems to be fine. Once I got the keyboard out I could see more of the traces across the whole mylar had turned black, so I thought I was in for a bad time, but it worked with just a bit applied to the ribbon part sticking out. Thanks all for the help! I may order a new mylar as a backup just in case but for now everything seems to be working fine.

 

The only thing I couldn't figure out when putting the computer back together was the metal clip on the rear expansion port. It seems to ride under the RF shield tabs. There are two short screws that seem to not bite into anything. Anyone know how that fits together again?

Another example... That fix works!!! ?

 

The pbi sheild can be left off honestly, but you have good advice from others here regarding how to reinstall. I've done some with and some without the shield.

 

[manterola]

Sometimes the problem is in the keyboard connector. So you need to test continuity from the mylar to the pcb motherboard. If the problem is there, you can cut with scissors a bit of the mylar, like 1cm or 1/2 inches or so. If it doesn't work, u might need to replace the connector itself.

But first, using a multitester you need to find the location of the problem.

 

Edit: I wrongly thought that the last post of page 1 was the latest post.  Now I can see that the problem was found and solved.

Edited May 29, 2022 by manterola

[erichenneke]

6 minutes ago, manterola said:

Sometimes the problem is in the keyboard connector. So you need to test continuity from the mylar to the pcb motherboard. If the problem is there, you can cut with scissors a bit of the mylar, like 1cm or 1/2 inches or so. If it doesn't work, u might need to replace the connector itself.

But first, using a multitester you need to find the location of the problem.

 

Edit: I wrongly thought that the last post of page 1 was the latest post.  Now I can see that the problem was found and solved.

Still good advice though! ?