HP IIP/IIIP 52 Service

A service error 52: (Apple Personal LW series indicate this error with the two lower lights flashing, QMS PS410 printers with the error light being lit) indicates incorrect scanner speed and is generally the same as an error 51. This is a very common failure on the laserjet IIP/IIIP, Apple Personal Laserwriter, QMS PS410 and other Canon LX engine printers. This error can begin as an intermittent error 51 which can be corrected by pressing Alt- continue (on HP printers) but it's only a matter of time until you can no longer correct it this way. Early models of these machines had a scanner assembly which contained a manufacturing problem causing the scanner speed control IC to overheat and burn out. This is sometimes indicated by the very distinct and pungent smell of a printed circuit board burning. When the defective part is removed, the board material under the speed control IC is usually burned.

The upgraded assembly part number is RG1-1771-030 available for $69.95, and includes step by step replacement instructions. The scanner motor assembly on this machine is buried deep in the center of the printer, and takes about three quarters of an hour to change.

We have seen this failure on machines with either very low page counts - 2-3K pages or between 8-12K pages. Of course it can happen at any page count. On the HP IIP you can get the page count by holding down the "ONLINE, MENU, and ENTER" keys while turning the printer on. Then press the "FORM FEED" key and then the "ENTER" key. You will see "00 SMODE" in the display, then "05 WARM UP" and finally the page count will be displayed. On the HP IIIP the page count is given on the test page and on the Apple Personal LaserWriter it's on the start up page (except the LS). Heat and moisture are likely to aggravate the problem and induce failure. The replacement parts which are made for Canon by Toshiba, do not have the manufacturing problem. In very rare instances, the laser diode itself will be the cause of failure, usually resulting in an error 51. Listen to the scanner motor, it should have a distinct "whirring" sound as the printer prepares to print. Once the proper speed is reached, it should stabilize and the printer should print. If you don't hear the motor at all, usually accompanied by an error 52 indication, the scanner motor is defective.

If you hear the motor spin but not stabilize and you get an error 52 the scanner motor is most likely defective. If you do hear the motor reach speed and then you receive and error 51 you may have a defective laser diode although this is fairly rare. We also have this part available, RG1-1769.

On the LJII/III and the Apple LaserWriter II series, this error is generally caused by loose connectors and may be indicated by an error 51 message. Many times the scanner motor will rev up and fail to stabilize - indicated by a whining motor sound. A common solution: Is to tighten the connectors at both the scanner assembly and the DC controller. This is accomplished by removing the connector from it's mate and tweaking or bending in slightly on the connector tabs. When reseating the connector, use a small flat blade screwdriver to fully seat the female connector ends. You may also find the tie wraps on the wire harness are to tight, pinching the wires and causing an open or short. Simply cut these off. Occasionally, the scanner motor will fail in which case it must be replaced. The part is in available on our parts page. Replacement is fairly straight forward requiring removal of the cover assembly, fiber optic cable, two connectors and four screws. We have found it is highly beneficial to replace the wire harness assembly and fiber optic cable when replacing the scanner since by this time you have probably already tried tweaking the connectors. While this involves more disassembly, our experience has shown it to be a worthwhile effort. These parts are also available on our parts page. Important: On the LaserJet 4 Series, an ERROR 51/52 is usually an indication of a defective scanner assembly. You should check for loose connections first of course. Color LaserJet 4500/4550 - 52 SCANNER ERROR (4500) or 52 PRINTER ERROR (4550) 1. Power Cycle the printer 2. Verify connectors J551 on the beam detect PWB, J1103 on the scanner motor, and J1006 on the DC controller are fully seated and connected correctly. 3. Replace the laser/scanner unit.

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