unknown

asked Oct 4, 2001 at 1:27pm
Hp HP LaserJet 4

HP4 Control panel button

I bought a second hand HP LaserJet 4. All seemed fine for a while, until I wanted to reprogram. The menu button does not respond. There is a faint noise like a ball-bearing shifting when I press it, but no response on the led display (which also is a bit patchy). Any ideas on how I might check out what is the problem? PS: There is smudgy carbon on interior surfaces and I wonder if this is simply toner residue or if the printer was part of equipment in a fire clearance.