Climber - Crystal screen (cleaning)

As soon as this very special Game & Watch arrived, I immediately noticed a problem… the buttons didn’t work. 🙁

These now very old objects may have been exposed to humidity, liquids, dust and it is easy for the contacts inside them to oxidize.
One of the most frequent causes is the corrosion caused by the battery, in fact if these games are stored and forgotten with the battery, over the years this could leak acid and ruin the contacts on the battery holder, but in the worst cases the damage could also extend inside of.

The keys on these objects are almost all membrane and their operation is very simple, there is a contact on the board, usually in the shape of a comb (it could be covered by a conductive material or only exposed copper).to), where a rubber is placed on top with a layer of conductive material in the center (the part that will make contact). The shape of the button is made in such a way that the conductive pad does not touch the underlying board and with pressure this closes the circuit so as to read the pressed button (as happens for TV remote controls).

It is easy for these contacts to get dirty or worn out over time, losing their characteristics, at the beginning the key will have to be pressed more forcefully until it no longer works.

To solve this problem, it is necessary to clean both the contact on the board and that of the rubber button.
The contact on the PCB can be cleaned with alcohol (isopropyl would be better), while the rubber can be washed with soap and water.
If even after cleaning the contact is not good, you can use a conductive paste (usually in graphite or other material) to be applied under the rubber key to give better conduction. Some time ago they used the tip of a pencil to spread the graphite on the key, the problem with this method is that in a short time the graphite will wear out and the key will no longer work, as well as dirtying the contact on the base.