NODEraser

asked Jun 15, 2011 at 6:56pm
Apple Apple StyleWriter II

Apple LaserWriter II Kludging

I don't know how many of you have even seen one of these printers in the last 10 years, let alone worked on one, but I thought I'd give it a shot. I have a total of 5 Apple LaserWriter II's (Canon SX) on my bench. Two of them work perfectly fine, but are kind of picky about their operating temperature--I assume the rollers are just old and need to be within a certain temp range to grab paper properly. When they are cold (ambient temp less than 60F), they sort of groan/grind when picking up paper and jam. When the ambient temp is higher than approx. 65F they print just fine.

The other three are in nonfunctional status, and I figure I can kludge at least one more functional printer together from these parts. The one I have selected to be the recipient of the swapped parts has the lowest page count of them all, so I'm assuming (hoping?) that the mechanical parts are in better condition than the others. There are two main issues I'm experiencing, which I will address in order:

1. One of the first things I came across, was that the main DC stepper motor doesn't turn when the printer is first powered on. So, I replaced the motor and the DC Controller Board. While testing and reassembling, I don't think there was actually anything wrong with either part because as soon as I had the bottom cover back on the motors stopped working again. Turns out that the motor will not run with the Cover Interlock Switch Actuator assembled/installed and depressed either manually or by the bottom cover. Is that indicative of a particular problem, and why the heck is there a cover interlock on the bottom of the printer, in an area only accessible by removing screws and the I/O Board?

2. Bypassing the problem addressed above, I got the printer in a state that would appear to be mechanically functional. Using the IINT board that came with this particular unit, it powers up and starts to print the initial test page, then has a sizeable delay after picking up paper (fuser warmup?) and then proceeds to eject a blank page with no visible attempt at creating an image. The IINT board will then display solid paper/jam lights and do nothing further until a power cycle. Just for kicks, I threw in a IIf board from my workhorse printer and it won't even get to the startup sequence and displays solid power/paper lights and a flashing jam light. The fuser doesn't appear to be heating up, despite trying a number of fuser/AC Power Supply combos, including a known good fuser and a factory AC Power Supply that I acquired with some other Apple New Old-Stock parts a while ago.

Parts Swapped/Replaced in Desparation:
-I/O Board (IIf Known Good)
-Fuser (Known Good)
-AC Power Supply (At least one better be good)
-DC Power Supply
-DC Controller Board
-Main Motor Assembly (Known Good)
-Laser/Scanner Assembly

Also, aside from the page in the manual that addresses the IIf/g diagnostic lights (which require some special adapter that probably hasn't existed in 20 years) is there a document somewhere that will convert the LWII's status lights into error codes or some other useful form of information?

I have a copy of the old AppleService manual that has been a help with swapping out parts, but like the version hosted here the troubleshooting flowcharts are missing. If I had access to that invaluable resource, I could probably get these things going on my own. Lacking that, any assistance would be greatly appreciated.
That switch on the DC controller board was not used in later models. It's something like males having nipples. Neither serves a useful function. I break them off the board.
Motors never go bad on that model, and I mean never. There are replacement pickup rollers available, we carry them.
Laser scanner assemblies almost never go bad as I've only seen 2 or 3 fail. Your problem points at a laser scanner issue. That would cause exactly the issue you're having where it pauses at registration, doesn't see the beam detect signal and ejects a blank paper and flashes lights. Did I mention that laser scanners almost never go bad? That's why you should try tweaking the connectors which do lose connectivity. Refer to this page and do both ends of both scanner connectors to DC controller board. http://www.fixyourownprinter.com/reference/guides/misc/tweak
by moe on Jun 15, 2011 at 8:59pm Add comment
Tweaking the connectors to the laser/scanner assembly did the trick, printing is now successful. However, I had to leave the interlock switch out... If that's a part that wasn't used, why would it prevent the motor from engaging?
by NODEraser on Jun 18, 2011 at 3:44pm Add comment
Guess I spoke too soon... The cable tweaking solved the image problem, but now the fuser won't heat. I tried a known-good fuser, it was still warm when I swapped it from another printer. Could that have something to do with the weird switch issue?
by NODEraser on Jun 18, 2011 at 5:48pm Add comment
That switch cuts off the power to the fuser. Like I told you, just grab hold of it and break it off the board. Without it, the fuser always heats up. Make sure any leftover metal pieces don't touch. Printer is better off without it. Have no idea why they wanted the heat to the fuser cut off without the bottom metal pan. What a totally useless function.
by moe on Jun 18, 2011 at 6:45pm Add comment
This has the same effect as leaving the actuator arm off; the main motor doesn't move at all during startup, and after the power light stops flashing I get flashing paper/jam lights.
by NODEraser on Jun 20, 2011 at 6:35pm Add comment
I'm thinking that when you put the fuser in, you missed getting the pins seated correctly in the connector. The connector floats and it's easy to get the fuser in 1 pin off. Remove the fuser and push the connector with your finger and drop the fuser down. That should align the pins correctly. With the fuser in wrong, you'll get the exact symptoms you're having. No heat, no motor movement and paper jam.
by moe on Jun 20, 2011 at 7:47pm Add comment