7075 vs 7085: When black is black enough?

[mrwho]

I'm at a customer who owns both 7075 and 7085 and I've been strugling with a 7085 whose blacks come "less black" than the ones on the 7075.

Is it me or is the 7085 less capable of printing pitch-black as the 7075 is?

The machines in question are 100k past the last PM, everything's been changed then, I've checked the sofware dipswitches, cleaned the drum shaft at the back, and still the blacks come out dark grey.

Should I leave it as it is or is there something else I can do?

Cheers!

[Albonline]

	Quote:			Originally Posted by mrwho
	I'm at a customer who owns both 7075 and 7085 and I've been strugling with a 7085 whose blacks come "less black" than the ones on the 7075. Is it me or is the 7085 less capable of printing pitch-black as the 7075 is? The machines in question are 100k past the last PM, everything's been changed then, I've checked the sofware dipswitches, cleaned the drum shaft at the back, and still the blacks come out dark grey. Should I leave it as it is or is there something else I can do? Cheers!

with new supplys in both units they will look pretty close on single sided copies,( 2nd side on 85 looks weak) the 85 cq will go down hill much faster than the 75. a few questions though how old are the drums? charge units? t/s units? developer units? do the copies seem to have trouble seperating from the drum on the 85?

[mrwho]

	Quote:			Originally Posted by Albonline
	a few questions though how old are the drums? charge units? t/s units? developer units? do the copies seem to have trouble seperating from the drum on the 85?

The regular supplies (drum, dev, pm kit) have around 100k. Coronas, although not brand new, are fairly shiny and look quite good (better than the 7075s even). The developing unit is the only one older than the rest of the stuff, but since it's not dumping developer and, appart from the blacks, the copies have a good quality, I'm assuming it's alright.
The machine has 5M copies on it, with the developing unit apparently with the same copy count (unless it has been swapped without the counter being reset, wich is fairly common, actually, at least for the parts that are less prone to be replaced. Techs around here are usually careful to reset the parts counter when doing PM).

[Albonline]

i assume that the drum adjustments were reset and adjusted? if so and you have repacked drum and developer bearings with conductive grease. then suspect hv2. we used to have a large fleet of the 85s that replaced 75s. a good percentage of them needed hv2 replaced. this said be aware that a 85 will never macth a 75 on solid black fills. (and run clean that is) you can tweek them but you will pay for it. ps check the H cut should be loose on 5 sheets of 20lb bond thight on 6. ck middle and ends as developer wears the blade open.

[mjunkaged]

I'd try a newer dev. unit if you have a spare. You may have worn hit rollers, or the magnet inside the dev. sleeve may be 'dying' of old age.

Gotta perm. rare earth mag., and not one of the new cheap 'rubber+magnet-powder' new cheap types!! I had Tosh. analogs that wouldn't keep a field past 4 years!

[HuronMan]

	Quote:			Originally Posted by mrwho
	Is it me or is the 7085 less capable of printing pitch-black as the 7075 is?

In my opinion, YES!!! Albonline has some solid tips. The only thing to add maybe to try tweekin the dip sw settings (5-0, 1) like the 7155-65's, but you risk misting. I have never been able to get comparable solids from the 85. I only have 1 left, but back in the day, customers drove me nuts with the light copy complaints.