Editing Sinclair ZX Spectrum+ Troubleshooting Guide (section)

=== Spectrum+ specific keyboard fixes ===

Two faults belong to the Spectrum+ keyboard assembly in particular:<ref name="ian" />

* '''Some keys not working, especially on the bottom row.''' Both ribbon cables are clamped to the keyboard case. Remove the clamps and carefully clean between the layers of each ribbon — around the clamped area — using a cotton bud and WD-40. When re-clamping, add extra packing between the ribbon and the clamp. This often avoids a membrane replacement entirely.
* '''A character printing repeatedly.''' This is caused by the keyboard membrane backing plate being clamped too tightly. Remove the keyboard top to expose the plate and its nine screws, then '''slacken by a quarter turn the screw or screws nearest the offending key'''.

When handling the tails, insert them with a slight side-to-side movement while easing the ribbon gently down into the connector. If the ends are crinkled, creased or cracked, you can trim back up to about an inch — but strip the insulated part an extra quarter inch or the keyboard will stop working entirely.<ref name="ian" />