HP 33E Decimal point ignored

[Eddie W. Shore]

I have a 33E that the likes to ignore the decimal point sometimes. Is this common in 1970s HPs as they age?

[AndiGer]

Normally there is some dirt under the pad.
The decimal point pad is easy to reach without (partially) removing the plastic keypad, just carefully lift it to clean underneath.
Sure, you have to open the calc under unmount the interior part in whole.
Andi