On Fri, 29 Nov 2013 06:59:27 -0800, "William Sommerwerck"
wrote:
Yesterday, the 4M started acting naughty. It first began printing the source
file (rather than creating a document).
Data loss. Check your connecting cable.
Then it switched to simply
"swallowing" the input, without doing anything at all.
Data loss. Loose Centronics parallel connector is the most common
culprit. I double that you're using a serial or ADB connection. The
JetDirect cards are a different horror story, but since you didn't
mention it, I'll assume that you don't have one installed. That
leaves a parallel cable.
Following Sherlock's dictum, the only logical thing left was a problem with
the printer's firmware, a problem that the printer's self-test system couldn't
locate.
My version is "That which is most obviously correct, beyond any need
of checking, is usually the problem". Check the cable.
Being poor, I don't have the heat on. It's been quite cold in my condo for
several weeks, and the thought crossed my mind that maybe the printer didn't
like cold weather. Perhaps the memory chips (which include the firmware) had
gotten a bit loose.
Cold is usually not a problem. However, going from cold to warm will
cause moisture to condense on everything inside the printer. This is
very bad for the toner and optics. Some bigger HP LJ printers and all
Brother laser printers have moisture sensors.
I pulled the chips and reseated them. Bingo! Now it works. Of course, it could
be a coincidence...
My guess(tm) is you wiggled the parallel cable, or flexed the
formatter board. The only items in sockets on the formatter are the
RAM chips. Those will usually produce an error message on power on.
It might also be a crappy soldering job on the larger chips, but those
will also produce an error message. That leaves the parallel
connector, which will NOT produce an error message.
And I suspect
the service shop would have had more trouble finding the problem than I did.
It would have been working when you arrived at the repair shop. It
happens all the time.
I'm about to recycle all my HP LJ III and 4 parts because nobody has
wanted one repaired in about 3 years. Want a box of HP 4 maintenance
parts and pieces? You pay shipping.
"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land
Notice that he didn't say that we know the RIGHT answers. Knowing the
wrong answers does not help much.
Also, notice that he knows the right answers, as in plural. More than
one answer is what lawyers, doctors, and consultants do by habit. Give
the client more than one answer, and force them to make the final
decision. If they decide wrong, then it's the client's fault.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558