NeXT Computers

NeXT Computer, Inc. => Black Hardware => Topic started by: bobo68 on February 24, 2016, 08:51:35 pm

Title: Diagnose a NeXT 400dpi Laser Printer
Post by: bobo68 on February 24, 2016, 08:51:35 pm
Hi,

I have NeXT 400dpi laser printer that looks very good from the outside. When I print something the job lands in the PrintManager which says "printing". But the printer never starts printing. The printer starts up together with the NeXTstation and its fan is blowing. When I take out the paper tray the NeXTstation tells me that paper is needed.

So the computer and the printer are connected and can communicate.

What can be done to diagnose the problem? Where can I see the status of the printer and error messages?

TIA
bobo68
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: bobo68 on February 26, 2016, 01:59:56 pm
I did more analysis but the printer would still not print. :-/

The printer reacts to nppower on/off commands. It also is able to communicate back its status (dialog saying no paper or hood open).

I disassebled it and found the "magic" test print button (it is on the pcb on the underside). Although the service manual says it would print a test page if you press the button, it does not. :-(

I'm still searching for a way to get a more expressive status from the printer. Do I have to hack a C program do get it?
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: NeXTnewbe on February 26, 2016, 07:21:39 pm
Quote from: "bobo68"I did more analysis but the printer would still not print. :-/

The printer reacts to nppower on/off commands. It also is able to communicate back its status (dialog saying no paper or hood open).

I disassebled it and found the "magic" test print button (it is on the pcb on the underside). Although the service manual says it would print a test page if you press the button, it does not. :-(

I'm still searching for a way to get a more expressive status from the printer. Do I have to hack a C program do get it?


can you share the service manual, please
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: bobo68 on February 26, 2016, 09:29:04 pm
It is right around the corner: http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXT%20400%20DPI%20Laser%20Printer%20Complete_OCR.pdf. Keep in mind that this is for LBP-UX engine printers, there are some differences to the NeXT laser. E.g. 2 compared to 3 screws holding the upper cover and the front cover assembly.

Then there are http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXT_Laser_Printer_Service.pdf and http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXT_Laser_Printer_Tricks.pdf.
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: bobo68 on February 27, 2016, 08:31:23 pm
I had some success. Found a utility named printer preferences ("PP") on a NeXT PD-CD. It show the status of the printer and allows to make some settings.

After I fed the printer with fresh paper it started to print but would not be able to pull the paper through (exept for one time).

Here is an interesting maintenance video for the printer: https://dl.dropboxusercontent.com/u/1429222/Videos/nextprinter.mov (can somebody copy it to the file area?).
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: Rob Blessin Black Hole on February 28, 2016, 11:56:33 pm
Quote from: "bobo68"I had some success. Found a utility named printer preferences ("PP") on a NeXT PD-CD. It show the status of the printer and allows to make some settings.

After I fed the printer with fresh paper it started to print but would not be able to pull the paper through (exept for one time).

Here is an interesting maintenance video for the printer: https://dl.dropboxusercontent.com/u/1429222/Videos/nextprinter.mov (can somebody copy it to the file area?).


Hello : I just uploaded it here :  http://www.nextcomputers.org/NeXTfiles/Videos/   Best Regards Rob Blessin 8)
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: pentium on March 01, 2016, 05:13:45 am
QuoteAfter I fed the printer with fresh paper it started to print but would not be able to pull the paper through (exept for one time).


It's quite normal for the intake rollers to lose their ability to grip the paper. I believe Rob still has a stock of replacement rollers.
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: Rob Blessin Black Hole on March 02, 2016, 06:14:16 am
Quote from: "pentium"
QuoteAfter I fed the printer with fresh paper it started to print but would not be able to pull the paper through (exept for one time).


It's quite normal for the intake rollers to lose their ability to grip the paper. I believe Rob still has a stock of replacement rollers.


The 2 most common failures are the intake roller , yes I have new ones Intake roller $15 and exit gears loosing teeth so paper doesn't go all the way through exit gear $10 ,  Also have plenty of new old stock intake paper trays both regular and legal size $20 or used $15 and exit trays $15 new or $10 used also NeXT Logo printer data cables $15 , Shipping on any of above is $7 US and $20 First Class international, they just raised USPS priority small box rates to the $33.95  .... they have been raising rates almost weekly lately.  Best Regards Rob
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: rockus on April 12, 2016, 08:43:39 am
Greetings,

I recently acquired a NeXTlaser for my TurboColor and it had the same symptoms:
- starting up when a print job was placed in the queue
- the queue saying Printing...
- but never doing anything
- not even with the infamous test button on the bottom side

Over the last couple weeks I worked on the problem on and off and dug deep into the electronics and test modi and even built myself a diagnostic unit that could be connected to the diagnostic port on the underside.

So, what was the culprit? It's the 210degC thermo safety switch that's failed open. I could revive the original one by freezing it for 2 days. But then it only worked once.

So I sourced around and found replacement parts and yesterday night I replaced it - together with a bit of patching the mounting, though.

I put in this one:
Honeywell 3450RC 80040501
(e.g. Mouser 785-3450RC-80040501)

If wanted, I can post photos of how I mounted this in the printer. The original mounting can't easily be used. But the most imporant part: it's printing again!

[Since the printer hadn't been used for months at least, I still need to do cleaning, though]

---

I also had then the problems of the paper not being pulled in properly. This was simple: the little switch, that detects if paper is in the tray, sometimes was stuck in the down position and prevented the paper from being pushed up completely against the intake roller. Once I made sure to always push that little switch up, the intake was fine.

Hope that helps,
Oliver
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: Rob Blessin Black Hole on April 12, 2016, 08:04:43 pm
Quote from: "rockus"Greetings,

I recently acquired a NeXTlaser for my TurboColor and it had the same symptoms:
- starting up when a print job was placed in the queue
- the queue saying Printing...
- but never doing anything
- not even with the infamous test button on the bottom side

Over the last couple weeks I worked on the problem on and off and dug deep into the electronics and test modi and even built myself a diagnostic unit that could be connected to the diagnostic port on the underside.

So, what was the culprit? It's the 210degC thermo safety switch that's failed open. I could revive the original one by freezing it for 2 days. But then it only worked once.

So I sourced around and found replacement parts and yesterday night I replaced it - together with a bit of patching the mounting, though.

I put in this one:
Honeywell 3450RC 80040501
(e.g. Mouser 785-3450RC-80040501)

If wanted, I can post photos of how I mounted this in the printer. The original mounting can't easily be used. But the most imporant part: it's printing again!

[Since the printer hadn't been used for months at least, I still need to do cleaning, though]

---

I also had then the problems of the paper not being pulled in properly. This was simple: the little switch, that detects if paper is in the tray, sometimes was stuck in the down position and prevented the paper from being pushed up completely against the intake roller. Once I made sure to always push that little switch up, the intake was fine.

Hope that helps,
Oliver
Very cool, yes pictures would be great ! .... the little switch.... is this on the paper try or internal  a photo of this would help !  Best Regards Rob Blessin
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: rockus on April 12, 2016, 10:31:44 pm
These are the photos of the thermo switch and my mounting. It's intended as preliminary. But as things go, it'll probably stay that way...

Ideally, from a historian's point of view, I would find out how to get the original mounting out of the point-welded assembly so I can re-use it...

(http://rockus.at/NeXT/IMG_2203.jpg)
(http://rockus.at/NeXT/IMG_2204.jpg)
(http://rockus.at/NeXT/IMG_2205.jpg)

Oliver
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: rockus on April 12, 2016, 10:43:02 pm
With "little switch" I meant the paper sensing switch on the tray side of the printer. The one, that's in focus on this picture, looking into where the tray slides in (is this the "tray bay", then? ;) ):

(http://rockus.at/NeXT/IMG_2212.jpg)

Oliver
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: barcher174 on April 12, 2016, 11:03:58 pm
I'm curious about this diagnostic unit you connected. Can you share more details?

Thanks,
Brian
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: Rob Blessin Black Hole on April 13, 2016, 06:36:02 am
Quote from: "rockus"With "little switch" I meant the paper sensing switch on the tray side of the printer. The one, that's in focus on this picture, looking into where the tray slides in (is this the "tray bay", then? ;) ):

(http://rockus.at/NeXT/IMG_2212.jpg)

Oliver
Great work Oliver, this may have been one of the main causes of the last 20 year of the NeXT laser printer apocalypse   ,may be you pulled the sword from the stone of sorts.

At any rate, I'll give it a go .... for many moons we have been driven nuts by the paper is jammed in your printer .   Replacing intake rollers often didn't seem to resolve this even with some pristine printers so I gather if I make sure that level is open or flipped back toward me,  I may be in business at least on some of these printers.   In reading through the factory Laser docs below page 2-27

D . Paper Jam Detection
The delivery unit paper sensor (PS331) detects whether paper s feeding normally
.
The microprocessor
(M- CPU)
determines
wheth~r paper is jammed by checking whether paper
1s present or absent
at the sensor at times stored in memory
.
.
1)
Paper does not reach
_the delivery un1t
paper sensor by the required time
.(Delivery unit delay jam)

........

Here is the Laser Printer doc in full http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/  

Thank you !

:D
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: rockus on April 13, 2016, 05:40:00 pm
Hi Rob,

Quote from: "Rob Blessin Black Hole"Replacing intake rollers often didn't seem to resolve this even with some pristine printers so I gather if I make sure that level is open or flipped back toward me,  I may be in business at least on some of these printers


That lever needs to be rotated up/inwards into the printer. I don't quite get if that is what you meant with "flipped back towards me".

Oliver
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: rockus on April 13, 2016, 05:42:33 pm
Quote from: "barcher174"I'm curious about this diagnostic unit you connected. Can you share more details?


Hi Brain,

it's mainly cabling, a PCB and some jumpers so I could connect various signals to either supply or GND. Nothing fancy. I'll post a picture tonight.

When I was in the middle of diagnosing the unresponsive printer, I was contemplating to make a real diagnostic unit out of it, just for the heck of it - but then the thermo switch revealed itself before...

Oliver
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: rockus on April 13, 2016, 05:45:23 pm
Quote from: "Rob Blessin Black Hole"
Here is the Laser Printer doc in full http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/  
Thank you !


Actually I really have to thank you for providing all these scans and other files!

Some nights, I went to sleep with a printout of the service manual in hand. And it was an unbound printout, so in the morning there was a sorting job to do :)

Oliver
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: NeXTnewbe on January 07, 2019, 02:01:22 pm
Quote from: "bobo68"I had some success. Found a utility named printer preferences ("PP") on a NeXT PD-CD. It show the status of the printer and allows to make some settings.

After I fed the printer with fresh paper it started to print but would not be able to pull the paper through (exept for one time).

Here is an interesting maintenance video for the printer: https://dl.dropboxusercontent.com/u/1429222/Videos/nextprinter.mov (can somebody copy it to the file area?).


Hi

where can I find the  utility named printer preferences ("PP"), please help
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: Rob Blessin Black Hole on February 07, 2019, 09:58:12 pm
Quote from: "rockus"These are the photos of the thermo switch and my mounting. It's intended as preliminary. But as things go, it'll probably stay that way...

Ideally, from a historian's point of view, I would find out how to get the original mounting out of the point-welded assembly so I can re-use it...

(http://rockus.at/NeXT/IMG_2203.jpg)
(http://rockus.at/NeXT/IMG_2204.jpg)
(http://rockus.at/NeXT/IMG_2205.jpg)

Oliver
Hello NeXT Community:  I have gone through 2 stacks of NeXT laser printers 20 total.   My findings are most of them will initially power up , if you can position your self to look in through the crack by the exit tray , you should also see an orange glow .

I noticed if that does not happen than logging in and using print manager , opening the cue and choosing test print will just sit at idle.  In looking at this post (thanks Oliver) , is this a symptom of the thermo switch being toast?

If it does glow and you log in and run a test print , it should glow again my guess is it is getting things up to temperature to print so then you hear the intake drive motor start up.

Then another issue crops up Paper jams: A few things can cause this:
1) Paper
Thick laser printer paper is recommended also microwaving a small stack for 15 to 20 seconds draws the moisture out
2) Intake roller
Chances are the intake roller has shrunk overtime and I've had limited success cleaning the intake roller and 5 smaller rollers and 1 longer roller
with Rubber Rejuevenator , in the example they use acetone.

http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXT_Laser_Printer_Tricks.pdf

Still doesn't work I did this for the first time ,lol after all these years , replaced the feeder roller , so there are 3 deck lid screws and then seven internal screws but the catch is the ones that hold the assembly to the case are cheap and easily strip if off center , it seems like 1 in 4 is torqued way down  so care ful right sized philip's screw driver is important .
taking the assembly out tight tolerances but she comes out and clips to remove old roller and put in new one .... took me twenty minutes.
and it worked with a catch ,

3)  the bloody expeller year on the printer is worn out ...

so I switch plans  surely I can just swap out this know good working new intake roller into a printer   that lights up and tries to pull paper in.

Thought I had one #20 finally  but started to strip the screw on the surface mount and I am being really careful. I need a reverse bit to back it out.  

I had success with 4 printers in the last few month's  but this whole batch has me rethinking everything, They can't all be bad as a few of these are in nice cosmetic condition and I suspect replacing the thermo switch and intake roller should have me back up and running.

The expeller gear replacement looks complicated  at any rate , I'm recycling a bunch of them that I think look ridden hard and put home wet, extracting the logo's , logic and emulator boards which we can use to make non adb sound boxes and will save few spare parts..... usually if your printer latches are broken and the deck lid pops up tis a sign of previous anger with the paper jam problem. I'm being patient so Matt hopefully i'll have a working one for you today.   I'm evaluating is it worth it for me to try and repair these I have a few listed for sale as props on eBay for $59.95 , if you are serious about repairing one , I will sell you one of the nicer ones it includes trays and cable and I also have cartridges for cheap $20 and I will tell you what I think is probably wrong with it , heck buy 2 for $100 for spare parts, new intake roller $15 , I may even order a couple thermo switches and take a shot at repairing a few ,

As I've used the same mono turbo system to test  all of these, so I'm going to make a fresh DD of the SD card  to make sure there is nothing corrupt in the printer spool files or  cache .

It would be nice to have software diagnostic that may point to the failed component , Brian any thoughts?

wish me luck I just need one working one to fill the order onto printer 21.

http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXT_Laser_Printer_Service.pdf[/url]
Title: Diagnose a NeXT 400dpi Laser Printer
Post by: Rob Blessin Black Hole on February 08, 2019, 05:11:07 pm
in addition to above blast , I also found this which should prove useful in Troubleshooting .

   Printer Troubleshooting
      If you have trouble with your printer, the most common causes are:

      Defining the wrong baud rate between your NeXT computer and the printer (see "Attaching a Printer" earlier in this chapter).
      Using a Macintosh serial cable. These cables are incompatible with 68040-based NeXT computers, and are usually incompatible with 68030-based NeXT computers.
      Using a serial cable designed for a 68030-based NeXT computer on a 68040-based NeXT computer. They're incompatible.

   For help in diagnosing printer problems, the file /usr/adm/lpd-errs might contain some helpful information. This file contains a log of any errors that occur during the printing process.

You can get further help in diagnosing printer problems by downloading the program ehandler.ps, located in /usr/lib/transcript (this is for PostScript printers only). This program makes the printer print a page listing any errors after each job is printed.

To download ehandler.ps, enter the following in a shell window:

lpr -Pprintername ehandler.ps

   Once downloaded, ehandler.ps continues to follow each failed job with an error sheet until the printer is reset or turned off.