I recently purchased a Commodore 64 breadbin style from ebay.co.uk.
When I fired up the machine, initially all looked good but the keyboard did not work. There were junk characters on the screen and if you used the keyboard it kept typing random characters.
Usually when this happens the keyboard simply needs a clean. It’s quite easy to clean a a Commodore 64 keyboard.
It should not take more than 30 mins to do this job.
You will need the following tools.
- A small Philips style screw driver.
- A soldering iron
- A pair of tweezers.
- alcohol wipes for cleaning the contacts. (i used glasses cleaning wipes)
Ok so you have everything you need.
Step 1: Open the case.
In order to open the case you simple need to remove 3 screws which are located along the underside on the Commodore 64 at the front. It was a shame, i needed to punch a hole in the warranty seal sticker on my c64 to do the job. While it clearly does not have a warranty, being 33 years old it sort of seemed a shame. Anyway that is essential in order to gain access.
Step 2: Inside the case.
Once inside you will see the underside of the keyboard, attached to the upper part of the case. This is attached to the base by two sets of wires.
The bigger bunch of cables on the left is used to connect the keyboard to the motherboard. Then there is the LED wire on the right.
My C64 has the flexible cardboard / foil RF shield. Later models have a metal shield.
Gently unclip this where it is attached on the right and fold back to reveal the motherboard.
Step 3 : detach the keyboard from the base.
It will be easier to work on the keyboard if you detach it from the base. You simply need to unplug the two cables. I like to photograph the connectors in order that I do not put them back on back to front if I forget which way around then go.
Gently pull both of these connectors upwards.
Step 4: Remove the PCB from the back of the keyboard.
In order to get access to clean the inside of the keyboard you will need to separate the PCB from the actual buttons / keys. There are 23 tiny screws. You need to remove them all. There are a couple that are under the tape over the wires. I chose not to remove the tape. I just made a small hole and removed the screw through it.
Step 5: Unsolder the shift lock key.
The little square with two wires on the underside is the bottom of the shift lock key. The two wires need to be unsoldered in order to remove the PCB.
I used my tweezers to hold the wire, and then heated the solder on the other side and then allowed me to pull the wire free.
Now this is done the PCB can be separated from the keys / c64 beadbin case lid.
This image shows the underside of the keys.
This images shows the contacts on the PCB.
Step 6 : Cleaning.
Now you simply need to clean the contacts to remove ay dirt of grime. I used alcohol based wipes for cleaning glasses, although you should probably use proper contact cleaner. Throughly but gently clean all of the contacts.
You also need to clean the little rubber bits on the bottom of each key. (sorry for the blurry photo)
Step 7: Reassemble everything.
- re position the PCB back on the keyboard.
- replace all 23 screws.
- re solder the shift lock key. (i used the tweezers to push the wire back in to the hole and then reheated. Once hot it just slipped back in to position and connected correctly)
- re attach the keyboard and LCD cables.
- replace the RF shield.
- re position the case back together.
- replace the 3 screws.