HP LaserJet 3600n Printer "13 20 00 error" Questions

...13-20-00 Jam in top cover or duplex area" when there is no paper jam anywhere in the printer. What causes this error message when there is no paper jam? Is there a fix for this? There is either a ...

...13 Turn the printer power off, then on. Error 20 Remove and re-install the Imaging Unit (make sure that Imaging Unit is locked in place). Turn the printer off, then on. Remove and re-install the Main ...

...13 16 Grayscales (Vertical) 14 16 Grayscales (Vert./Hor.) 15 16 Grayscales (Vert./Hor Overlay) 16 Not used 17 Horizontal Line (1-dot) 18 Grid Pattern (Single-dot) 19 Grid Pattern (Double-dot) 20 ...

13:IC(BK=00000 C=00000 M=00000 Y=00000) 14:Power(SON=00009 SOFF=00009) 15:REG=0 16:UR(A(BKoe)=+01 B(Coe)=-01 C(Moe)=+01 D(SCoe)=-01 E(SMoe)=+01 F(BKbi)=+01 G(CLbi)=+01 H(BK-CL)=+01 I(SCLbi)=+01 J(C-SC

...13) Feed the new wire through the opening in the right hand side of the printer (through which the old wire ran) 14) Following the wire harness, pull the new wire to the terminal on the circuit board ...

...13.20.00 on HP LaserJet P3015 My printer displays the error 13:20:00, which was jammed in the fuser, but there is no paper jam and apparently the fuser sensor also has no problem. It is most likely ...