Recently my HP48GX calculator decided to not turn on anymore.  At first I thought time to change the batteries.  To my horror putting new batteries in the calculator did nothing.  Then I thought to myself oh no the screen finally bit the dust.  After searching Google I came to the conclusion that the screen was most likely fine, but the contacts on the motherboard because of age have somehow fallen apart.  I was able to finally hit the calculator enough and was able to use it once again.  Whacking the ON button or slamming the case against a desk didn’t seem like a very good fix.

Read more http://bwengr.com/hp48gx-caclulator-button-workaround/