HP 870 paper feeding

I've had an HP 870Cse printer for the past few years. Recently it's
had a problem pulling paper in, consistently trying, then giving
up -- ultimately requiring manual intervention to get each sheet
properly fed.

I've tried cleaning the rollers with some alcohol -- kind of difficult
given their accessibility. This helps somewhat, but then the same
problem comes back shortly.

Any suggestions/advice on how to fix the problem?

Thanks!

Jim