You do not need to throw away your old calculator. It has served you well for close to 30 years, hasn't it? HP calculators of the past were generally well built, and most can be repaired with not too much difficulty. The functionality you can buy today is greater, but unless you are a student, it is likely that you don't use it. Instead, you switch on your Excel spreadsheet and do it with greater clarity. What you really need it what you were accustomed to.
Most of HP's old calculators were quite well built and can be successfully repaired. We offer a repair service for all HP calculators of the past (not the current line, which is better bought again than repaired). Due to the very different possible repairs, we can give you a quote depending on your problem. Please contact us at firstname.lastname@example.org with your problem