Keyboard - some keys stop working - T540 hardware problem

[Snowflake]

The T540 keyboard has about 7 of its keys, stopped working. The seven keys are usually on the right hand side and in a group, but could be in any row, and within 1 or 2 columns of each other. Pressing the key does nothing, not even the click in click mode. I am convinced this is not a software problem as I have tried all possible software remedies. I am sure it is due to the keyboard or connection itself.

First time this happened after a year of use, I lost 'P' and '0' among others, and I had to replace the keyboard. A year later on the new keyboard it happened again, but came back after two days. 3rd time was four months later, and I have lost '-', '=', '5', '6', delete, and others. I remapped these. Then again now I lost another bunch including '\', backspace, enter, and space.

The original keyboard is a backlit keyboard FRU 04Y2387, ID# 48L16M, Parts # 0C44952, Model # KM BL-105US . Replacement keyboard also backlit and exact replacement.

Short of replacing the keyboard, or resetting the keyboard connection and cleaning the contacts, (all tried) what is there to do?

Is this a contact problem or keyboard problem? Has happened with two different keyboards. Is this a common problem?

Any help will be of great assistance and will be greatly appreciated.