HP Laserjet 4, Paper jam error

[Civilian_Target]

I've recently got my hands on a second hand laserjet 4 printer, but it
keeps giving me paper jam errors, even when there's no paper jamming
in it, or when there's no paper at all. In the upper feeder, it simply
makes the paper shake a bit, in the lower feeder it crinkles the
edges, but fails to pick the paper up. The problem seems to be
reasonably well documented on HP's website, but unfortunately most of
the knobs, levers and sensors it refers to aren't on the printer.

The paper I'm using is A4, new, 80g/m^2

Civilian_Target
"To truly know a man, they say you must walk a mile in his shoes. That way, if you don't like him, you're a mile away from him... and you've got his shoes!"

 

[Civilian_Target]

I've recently got my hands on a second hand laserjet 4 printer, but it
keeps giving me paper jam errors, even when there's no paper jamming
in it, or when there's no paper at all. In the upper feeder, it simply
makes the paper shake a bit, in the lower feeder it crinkles the
edges, but fails to pick the paper up. The problem seems to be
reasonably well documented on HP's website, but unfortunately most of
the knobs, levers and sensors it refers to aren't on the printer.

The paper I'm using is A4, new, 80g/m^2

Civilian_Target
"To truly know a man, they say you must walk a mile in his shoes. That way, if you don't like him, you're a mile away from him... and you've got his shoes!"

Solved. The plastic paper guide in the lower casette was bend up and
out, which was causing the paper jams from both trays. Turned the
printer upside down, found it, and had it sorted with a pair of pliers
in 15 mins.

Civilian_Target
In the ongoing battle between objects made of aluminum going hundreds of miles per hour and the ground going zero miles per hour, the ground has yet to lose. - The alt.games.battlefield1942 flight manual