HP3500 printers, color printing, normal black print out - Shenzhen drum manufacturers
phenomenon description: HP3500 printers, color printing, normal black print out.
failure analysis: to consider may be machines and drum unit contact contact dirty contact is not good, after cleaning problems unsolved. After consideration is the issue of black drum unit, after the replacement problem unsolved. And maybe laser shutter is not open, artificial card black laser shutter, after processing problem still unsolved.
after the analysis of the drum may not turn, make a mark in the side of the drum, after put into the boot, then observe the mark on the drum has moved, is given to illustrate the turn of the photosensitive drum.
and may be developing roller not turn. As shown in figure 5 - Shown in 52, M3 driving four photosensitive drum and the transfer printing belt. Three color normal photosensitive drum, transfer belt drive is normal, the M3 works well, and drive the three color development roller M4 working properly. M3 also electromagnetic clutch CL2 driven by black developing roller, now the color is normal, black out completely, after rule out other causes, judgment must be CL2 problems.
as shown in figure 5 - said power transmission 52 o compact power lose schematic
processing method: after the replacement of CL2 is normal.
note: this type of laser printer and HP1600 similar, is also a four laser head, two sets of scanner, so like this kind of monochromatic out fault, generally do not is a question of laser. But to consider laser is normal open the shutter.