Printer help?

From: der Mouse <mouse_at_Rodents.Montreal.QC.CA>
Date: Thu Sep 9 15:43:53 2004

[, there's a note addressed to you some 2/3 of the way
through, in case you'd otherwise not read the whole thing]

[msokolov_at_ivan.Harhan.ORG (Michael Sokolov), two different messages,
both replies to me]

>> Duh, I forgot to say: I've more than removed the dead cap.
> Where was it? I thought it was on one of the PSU boards, but you now
> seem to imply it's on the DC controller.

Based on your description of what's what, I think so: the board it's on
matches your description of the DC controller.

> The control panels lights and LCD are controlled by the formatter
> board. That's the ... the ribbon cable from the control panel plugs into. :-)

> The fact that it walks the lights, enters the self-test and knows
> about PS indicates that the formatted board is probably OK.

This is no surprise to me, since the trouble appears to have been
entirely elsewhere.

> The formatter board throws up a 55 error if it can't talk to the DC
> controller. If the board you are having woes with, the one damaged
> by the blown cap, is indeed the DC controller board, then it's
> probably the culprit.

Then it seems likely to me that a main power supply line got shorted
and decided to play fuse, and the DC controller is now getting no power
at all. I need to sic a voltmeter on some of those connections and see
what it can tell me. [But see below.]

> If you take a close look at the front cover between the tray openings
> and the font cartridge slots, you'll see a small hole. This hole
> provides access to the engine test button on the DC controller board.

Okay, it's definitely the DC controller board, then. I saw that switch
and wondered what it was for; I couldn't see anything that would push
it, but the presence of a plastic extension to make it pushable clearly
indicated it was deliberate.

> If you push this button, the DC controller will print an engine test
> page independently of the formatter, i.e., it'll forcibly override
> whatever the formatter is directing it to do and will work even if
> the formatter is missing or dead. Try it. But it looks like your
> problem is the opposite, good formatter and bad DC controller.

I went to do this, but when I put it all back together and turned it
on, all armed with a voltmeter to check power, when I turned it on one
of the LEDs on the DC controller board came on, something I cannot
recall happening before. So I just let it sit, and darned if it
doesn't work fine - all sprawled all over the table, but working.

However, the selftest button does not work; as far as I can tell it
does nothing at all. I even tried holding it in for some 15-20 seconds
and it still did nothing, despite printing working normally from the
network and printing a selftest page when told to do so using the
front-panel buttons.

> Someone just posted about having a bad HP 4SiMX for free for the
> taking. He said it jams, so that's probably a mechanical problem and
> the electronics is probably OK. [...] You'll need both boards and
> the cable between them since it's a 4Si. Since the two printers are
> otherwise identical, swapping those two boards will turn your IIISi
> into a 4Si, i.e., you'll get 600 DPI and PostScript Level 2.

Now _that_ would be nice (both of those).

I think this was Peter Wallace, Peter, might you be
willing to do that? I'd be happy to snail you a cheque for postage and
a bit on top of it for your time.

> And if you two do work out that arrangement, I could take the rest
> for spare parts next time I'm in the Bay Area. (I'm in Southern
> Calif.)

If nobody takes it before then, and Peter isn't willing/able to, might
_you_ be willing to extract those and send them to me?

>> (There are two sockets with no cables to plug into them as far as I
>> can tell; I don't _think_ I have any cable ends hiding, but....)
> The big cavity clearly visible from the rear with the covers off is
> for the duplexer. The socket in the corner of this cavity [...]

> The other socket is on the front directly above the upper tray [...]

No, neither of those. I refer to two sockets on the DC controller
board. One is a two-pin socket in the upper right (looking from the
right side of the printer at the board mounted in place), the rightmost
socket on the top edge of the board; the other is a socket of, if I
counted right, 30 pins in a 2x15 array, on the left edge of the board;
the bottom edge of this socket is immediately above the self-test
switch you describe (but on the other side of the board). The former
is marked as J005, the latter J014.

Since it works apparently fine as it is, and I can't see any cables to
plug into either, I'm inclined to ignore them. (I really should have
been taking better notes when dissecting it originally....)

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Received on Thu Sep 09 2004 - 15:43:53 BST

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