LaserWriter problems? Might be the dreaded capacitors.

[Mike Richardson]

In the deep dark depths of my warehouse I found two lonely LaserWriter Pro 630s.

One would fire up and try to print the test page but would jam. Another one would turn on but sit there dumbly.

I took the formatter board from the one that printed and put it into the one that sat there dumbly, and now I have one functioning printer that successfully prints the test page.

Noticing the bad formatter board I saw the tell-tale surface mount capacitors and the magic goo leaking from within them. I know the working LaserWriter will succumb to this fate in due time.

So, to make a long story short, check your LaserWriter for leaking caps on the formatter board. Replace caps and try again. I'll give it a shot on the board I have here and report back. (in a few months - too busy right now)

 

[Unknown_K]

Never heard of that problem, but I am sure it can happen.

 

[MacJunky]

So, to make a long story short, check your LaserWriter for leaking caps on the formatter board.

I had my LWS360 open the other day and almost every capacitor in it was either leaking or bulging. Only a couple in the PSU had failed though.
We should compile a database of the rating of each cap in each of Apple's laser printers.

Just because we can.

 

[jwmcfarlin]

A little thread resurrection, but I'd rather not start a new thread when there's one already up.

So, my question, seeing as how I have a Laserwriter 360 in good cosmetic shape but which when turned on blinks the green light at me for a while and then nothing, would be how should I check the capacitors? I could just start undoing every screw in sight, but that might prove counterproductive.

Best,

John

 

[beachycove]

The first step in rehabilitation is to read the Service Manual, and pay attention to exactly what happens on startup. The behaviour of the lights in particular (time spent flashing, number of flashes, etc.) is often used for diagnostics, along with sounds if you know what you are doing. You can have everything from bad RAM, to motor failure, to stuck rollers or a bad fuser, to a small piece of paper stuck in the paper feed to contend with in a LaserWriter, and any one of them can cause malfunction. Much of the workings of a LaserWriter are purely mechanical, and sometimes all that is needed is lubrication.

No doubt the flashing lights were not designed to tell you that your caps are bad, but as your caps may effectively be fine, flashing lights are the place to begin.

To take a concrete example, my LW4/600 will not work if a single fragment of paper is left in the mechanism after a paper jam, no matter how small. Typically these are to be found hidden under a plate in the left front corner. You have to loosen a screw in order to flick the hidden little bit of paper out with a knife or some other tool and, and all is well again.

 

[jwmcfarlin]

Of course that's spot on advice. Is purchasing a PDF file from a seller like this:

http://www.smpcshop.com/LaserWriters-Printers-p-1-c-189.html

standard practice for getting that document?

Best,

John

 

[Gil]

Get it here:

http://www.retrocomputing.net/info/siti/apple_repair/www.whoopis.com/computer_repair/index-plain.html

 

[jwmcfarlin]

Of all the crappy luck, that file is unavailable.

Best,

John

 

[jwmcfarlin]

I got lucky. I received a new toner cartridge today, installed it, and bam: nice clean test page. So, looks like I am in business with that LaserWriter and don't need to go poking around inside.

Best,

John