Minolta DI551 printer - not dark enough on print

Try a sheet through then invert it and pass through again. If a marked improvement second time put the ream of paper in a very low oven for a few hours

Humidity or damp paper is not the problem...plus the machine has three stacks of different sized paper to draw on and all behave the same.

It is quite consistent in the print quality - grey instead of black. I'm going to dig in the developer section next, I understand there is a gear that gets stripped and may lead to this sort of result.

John :-#(#

From my days (15 years ago) as a copier repair dispatcher I would say that you need to clean the corona wire. I have no idea whether your modern printer even has a corona wire anymore, but if it does, then there will usually be a little sliding button on the side of the toner/drum cartridge. You slide that back and forth a few times to clean the wire. Good luck!

Copiers and laser printers haven't used corona wires for about 15 years. The problem is that the air gap and high voltage between the corona wire and the drum would produce ozone, which is deemed hazardous to humans and rubber parts in sufficient concentrations. These daze, there is a "charge roller" inside the cartridge that servers the same purpose (scrape off residual charge from the drum).

Thank you mentioning the model number. That's always helpful. It would also helpful if you would do a better job of describing the symtoms in terms of whether you're using it as a printer, copier, B&W only, color copier, etc. For example, when you say that the scanner function works fine, does that mean it works to an image on a computer screen, or a printed paper image reproduced on copier?

The DI551 is a color copier. What do the other colors produce? Each color has its own drum. If only black is printing badly, then look around the black toner bin or drum for oddities. If all the colors are printing equally dim, then I would suspect the high voltage power supply is either misadjusted, or fried, since they all share the same power supply. You might also check the optics. Crud or evaporated volatiles splattered on the lenses or rotating prismatic mirror can produce light output.

Also, having plenty of toner is quite different from having the toner actually delivered to the drum. It doesn't take much to clog the feed mechanism. You'll find plenty of toner in the reservoir, but because the flow is obstructed, little of it makes it to the drum and printed page. If you suspect this might be the problem (especially if ONLY black is printing too lightly), then keep your fingers out of the toner bin. The slightest amount of sweat or hand oil will cause the toner to stick, clot, and eventually clog the mechanism. Rubber gloves are a good idea, but you also don't want to be eating potatoe chips while wearing them.

Another forum where you might get some more specific answers:

Good luck.

John Robertson Inscribed thus:

Could be dirty corona wires !

The scan (B&W) has good density, and prints out just fine through another of my printers.

Actually the Di551 is B&W only, no colours - if it was colour I'd be more willing to sink some $$ into it.

Joined them last night, but - see below.

Hi Jeff,

Turns out he machine hasn't had the 'kit' installed for perhaps 300K+ copies and so I can either sink $795 into an old B&W printer/copier or get a much newer machine for $1500 that does colour and will even do banners (up to 17" X 49").

I've decided to replace the machine...

Thanks for the suggestions though!

John :-#)#

How does it print on the DI551 when you use the *COPY* button?

Sorry. I thought is was a color copier.

The $800 kit is probably a new drum, some rubber parts, a tech visit, and LOTS of cleaning. Did you shop around for the rebuild kit? Here's one for $390.

Here's one marginal kit for $175

Several more found with Google around $300-$400.

Such copiers should run for well over 1 million copies. 300K pages is not old. If the overpriced $800 kit is your only option, I agree with getting the Oki printer. $1500 is cheap for color. You might want to calculate your operating costs per page as a sanity check. I smell something fishy, but I can't tell what is odd.

As I said, the print on the DI551 is poor quality, but the scan works fine.

My printer had something like 1M5 copies over its' lifetime...one of the main reasons to retire it after all.

John :-#)#