How to stop misc diagnostic printing from my Hp Printers running on a jetdirect?

I think that you'll may need to explain what you mean by "misc diagnostic printing", and whether you are referring to LaserJet or DeskJet printers, before you get any meaningful responses.

If you just mean that the printer(s) is/are printing pages and pages of what appear to be random characters, then this is a symptom of the incoming (binary) print stream being corrupted; the printer can then lose its way, and doesn't know whether the data it is acting on is a control sequence, or text to be printed, so just assumes the latter and prints it.

If so, possibly a driver problem, but more likely to be random corruption of the print stream by hardware glitches (e.g. bad cable, connector, NIC, port, etc.), or even the printer formatter itself.

Diagnose by a process of elmination, replacing one component (e.g. cable) at a time.

The Diagnostic Page that I was refering is as follows:
JetDirect Diagnostic Page
An event has occurred that has caused the JetDirect to reset.

Product Number J2591A
Firmare Rev. E.08.40
S/W Exception 0007
PC: 11cd4

then list the Resisters: Stack: Call Chain: With lots of numbers and letters.
This looks like a memory problem or a memory dump etc.
IF you need the report let me know hopfully this is enough info the help fix the problem

Thanks

I'm sorry, but I can't help with JetDirect and/or communications problem diagnosis - not my area of expertise.

But, hopefully, someone else may be able to offer some advice.

Try doing a cold reset on the JetDirect. If this is an external JD, use these steps:

1. Remove all cables.
2. Press & hold the Test button while powering on & continue to hold the buttons for 10 seconds, then release it for 10 seconds, then power off again.
3. Connect all cables & power it back up.
4. Set the JD's IP address details to the correct values.

If it's an internal JD, tell us the model of the printer.

In general, try giving as many details as possible with a question. The more info you provide, the less we have to guess.

This problem is for several customers and the errors veryfrom customer to customer.
1) This error happen with a new JD install
2) This error was a install that failed after being in place for 1 year, then started to give an error for no apparent reason.
Thanks for the advice I will try and reset the JD.