Printer Faults - Dropouts In Black Areas

Areas of dropout in areas that should be a solid black are most likely to be a lower than needed developer voltage. Try turning the print density up a bit.

Use a manufacturers original cartridge. Differences in toner type and wear on precharge, developer and OPC rollers could cause this kind of fault.

There could possibly be a voltage issue. Try cleaning the cartridge contacts and make sure the transfer roller and its area are clean.

The transfer roller and OPC have to be prime suspect in this kind of fault. Do either show any kind of problem?

Some printers, especially older models and those at the lower end of the price spectrum aren't entirely capable of a really solid black print.

In the end analysis why do you want a really black page? There is a reason why solid black areas are unusual in computer printing - it's because white print on a black background costs 20 times as much as white on black.

Dropout Flecks in Black

Little flecks of dropout and small lumps in black areas might be due to the wrong type of toner. Small dropout flecks in black on a large copier often result from a strange user habit of pouring waste toner back into the toner hopper. Waste toner isn't just toner powder; it's toner powder with electrostatic properties that have changed by passing through the print process, mixed with paper and other dust.