Encad novajet 700-42 PH issue

[ABStech]

we have a used Encad NovaJet 700-42 wideformat printer. as the name would indicate, its an ink jet (yay). we're currently having issues keeping the black printhead primed.

we don't actually use the machine, its a used machine we're holding onto for rental and potential sales. but as there are a host of known issues with the ink feed system connected to disuse, we do check out the machine once a month and put it through its paces.

the black print head has been a problem. earlier this year it started requiring a 'warm up' print where it would start printing partway through the job. now we are unable to make it print consistantly (if at all).

attempts to prime the PHm, at best, result in temporary function, but the prime runs out after a very short time.

the problem is specific to the black PH itself, as we can swap the Cyan and black PHs and the subsequent test print will have cyan in the black areas and will be black in the black areas (versus full color and blank for black)

anybody have any good suggestions other than replacing the printhead or re-attempting to prime it? have been working on this off and on for several days and am getting a bit frustrated. new printhead is not an option as management doesn't want to put money into parts without a client lined up?

[ExOceMan]

I have worked on these units many years ago, and recall that the heads would require priming very regularly. Sadly it was one of the worst ink jet machines I have ever dealt with. The bulk ink tanks and such on some of these machines were nice, but really who wants to toy around with a 10+ year old ink jet printer. As far as getting your hear revived here is a good trick:
1. Get some de-ionized water (If you don't have it, bottled water should work)
2. Put a very small amount maybe 2mm deep in a cup, or container that will hold the head.
3. Soak the bad head overnight.
4. Get a lint free cloth and blot (don't rub) the print head surface.
5. Install the head back in the machine.
6. Test
7. If no luck tell them they should buy a head. (If there is one available they should buy whatever they can as these are the worst heads around.)