HP LaserJet 4250 Service Manual - Page 388

Jams in the paper path NOTE Avoid using odd-sized media. Odd-sized media might not travel between the transfer roller and the fuser without getting jammed. Avoid using short-grain paper. Short-grain paper might curl excessively and become jammed. This type of jam is often found between the fuser and the output destination or in the duplexer. Table 7-12 Causes of paper-path jams Cause Solution The cartridge shutter open/close mechanism is damaged. The shutter in the print cartridge should open as you insert the print cartridge. If the shutter does not open, replace the print cartridge. The registration roller is dirty, worn, or damaged. (This applies to jams that occur before the media reaches the registration rollers.) Clean the registration roller assembly if it is dirty. If it is dirty after cleaning, or if it is worn or damaged, replace the registration assembly. See Registration assembly. The paper-feed assembly (including clutch CL101) might be damaged. (This applies to jams that occur before the the media reaches the registration rollers.) Replace the paper-feed assembly. See Paper-feed assembly. The drive gears are damaged. (This can cause jams that occur before the media reaches the registration rollers.) Check the drive gears in the paper pickup and main drive assemblies. Replace the pickup or main drive assemblies if the gears are damaged. See Paper-pickup drive assembly or Main drive assembly. The pre-feed (PS102), top-of-page (PS103), or fuserassembly (PS108) sensor is defective. The dc controller PCA is defective. Replace any defective sensors. See Printer switches and sensors. Replace the dc controller PCA. See Dc controller PCA. Jams in the duplex path Table 7-13 Causes of duplex path jams Cause The oblique rollers are worn or damaged. The oblique roller drive gears are worn or damaged. The reversing motor is defective. The duplex feed guide is damaged. The duplexing unit feed belt is cut or sagged. The duplex sensors are defective. Foreign materials or burrs are present on the reversing or feed guide. The dc controller PCA is defective. Solution Replace the duplexer. Replace the duplexer. Replace the reversing motor. Replace the duplexer. If the duplexing-unit feed belt is cut or sagging, replace the belt. Replace the duplexer. If foreign materials are present on the reversing or feed guide, remove them. Replace the guide if it has burrs. Replace the dc controller PCA. See Dc controller PCA. 374 7 Troubleshooting