Texas TI-58: Repairing the keyboard bounce and miss to register keystrokes

[circuityrboy]

This might be of interest:
I acquired an LED TI Programmer on eBay. In fair condition, it ran when rechargeable power pack was replaced with a PP3.
However, it proved almost useless owing to frequent keyboard bounce/non-entry. This was worst in Hex mode down the F to 3 column of keys. Gentle 'key exercising' didn't help.
At that time I had not seen anything online about dismantling so I inspected inside the battery compartment to see how things went together.
With keys down and supported at edges on my fingertips, I pressed with thumbs on the white back of the keyboard to see if there was any movement. Mainly at the edges, but also flexing the centre of the white panel.
I didn't learn enough to attempt dismantling, but I then found that the keyboard was restored to clean key action.
Obviously, I recommend trying this before undertaking any TI surgery.