Login
Back to forumReply to this topicGo to last reply

Posted By

register
on 2009-06-13
14:30:03
 Cleaning the plus 4 keyboard

Hi boys,
I need to verify and eventually clean the keyboard of a newly acquired plus4. This is the first time I open the beast so I would like some suggestion from someone with more experience than me. Basically after removing the first 5 screws I found another set of very small screws on the keyboard. After removing also them the keyboard is loose on one side but still it sticks on the side where there is the cable connecting the keyboard to the mainboard. Since I don't want to run the risk of breaking something I am waiting for your masterful instructions.

Thanks!!!!
Register

Posted By

TLC
on 2009-06-13
15:37:48
 Re: Cleaning the plus 4 keyboard

I'm writing from memory (I used to use a C-16 rather than a Plus/4; I only made this procedure on Plus/4 keyboards for few times and pretty long ago).

The flat cable connects to a socket on the mainboard; you can pull it off safely (putting it back will need more attention).

You can then separate the keyboard block from the top cover (also a matter of removing some screws).

To disassemble the keyboard,

1.) desolder, or cut wires that connect the shift lock key to the board (I'm not sure, but as I remember, even the Plus/4 keyboard has a shift lock switch connected to the board by wires),

2.) remove the screws that hold the board to the keyboard block,

3.) carefully remove the board -- you'll especially have to keep attention on not losing 1.) a small gold coated coil spring (about the size of the screws) somewhere in one of the corners. 2.) a couple of rubber bells (contacts) under the F and the cursor keys, at this point.

You can use domestic (neutral-ish) cleaning supplies to clean both the keyboard and the printed circuit board. This is to remove most of the dust and fat (which you'll find plenty of around and on the keys). Then dry them.

Clean all rubber gold plated contacts using alcohol. This ensures that all dust and fat is removed, whilst not dissolving the contacts wink.

Carefully reassemble the keyboard. You might want to take pictures of the unit while disassembling, so that you'd have less doubts at this part wink. (Also, don't forget to put the small copper sheet spring, which is held by one of the screws, back to its place. The wires connecting shift lock will need to be soldered back (as far as I remember).

Thats's probably all...

Posted By

TLC
on 2009-06-13
15:39:22
 Re: Cleaning the plus 4 keyboard

Eh...

I meant... "rubber, _and_ gold plated contacts", of course :-/ .

Posted By

register
on 2009-06-13
16:16:43
 Re: Cleaning the plus 4 keyboard

Yes there is a shift lock and it happens that the keyboard is stucked right there....
Another question: following your instructions I will break this key right? Because the keyboard still works even if it is a little bit unresponsive, so maybe breaking one key isn't worth the effort....
Thanks,
Reg

Posted By

TLC
on 2009-06-13
17:14:35
 Re: Cleaning the plus 4 keyboard

Hmmm, I of course missed the simple fact that you were already far beyond the point of disassembling the keyboard to parts. I'm sorry.

I took a Plus/4 apart now (so that I could inspect how the shift lock is mounted). Disconnecting these two wires here needs (de)soldering. Without that capability, the most that you can do is to cut them, and either leave them as they are (no shift lock anymore), or twist the respective wire ends together as you can, after having reassembled the keyboard (which is an ugly hack, and might even be impossible in that particular case, but anyway... ).

I can't judge if it's worth or not worth the effort for you happy. I could live without a shift lock, but obviously wouldn't want to do that wink)). I also won't want to keep cursing about an irresponsive keyboard... wink) So neither one would be the answer for me.

Obtaining a cheap soldering iron from a local electronic store or eBay might be an option; this is an easy part to solder and you also can't really break anything, as long as you keep the keyboard disconnected from the motherboard.

One final note: be careful with the red power LED, when you make an attempt to reassemble the keyboard... they're fragile.



Back to topReply to this topic


Copyright © Plus/4 World Team, 2001-2024