asked Feb 12, 2004 at 7:46pm
Apple Apple StyleWriter II

LaserWriter II Fuser Problem

Greetings to all!

I recently aquired a nice Apple LaserWriter II Printer. The unit was working just fine until the owner recently replaced the Toner cartridge, upon which the Fuser apparently died. The two Paper Jam and Paper Out lights flash at me after about 1 minute warmup.

I've stripped down the entire bloody printer, and it wasn't that fun to do. I've tested the Thermistor in the Fuser Assembly, the Fuser Lamp (2ohms across its 2 120v plugs), all seems good. The Engine Test button has no effect.

I just replaced the infamous Q101 in the AC Module (more fun there!), with a NTE5609, which supported the 120v AC and 8 Amps. Afterwards, I sat there watching it come on, and, nothing. Same two lights of death blinking at me. I measured the voltage across the fuser lamp's plug (tripping the switch for the case so it thinks the case was closed as I had my DMM sitting there), and the measurement was around 0.157v, it never even once hit 120v AC as I think it should.

AFAIK, the unit "just stopped" working when the toner was changed. Its a 10 year old printer in simply incredable shape, they've never had any problems with it before (except the odd alignment problem).

I am prepared to purchase a new AC module. But I must know- what else can I do to make sure that it IS the AC module and not the DC controller?

Its a Canon SX based machine. I'd love to use it in the future, the ability to use SCSI HD's for font storage is really cool :).

Is there any way to test the DC Controller, or, is it forsure probobly the AC module? Do they just "die" like this all of a sudden (instantly?)?
First I would like to thank you for pointing me in the right direction. I was experiexing a similar problem with my HP Laser JetII. It was working OK before it went into semi-retirement when I replaced it with a HP R40 color/printer/copier. The R40 has stoped working with a "fake" paper jam, so in the mean time I conected the HP II. It would warmup, go normal and then go in an error 50.I checked the fuser lamp and sensor resistance - OK. Power supply voltages looked OK as far as I could tell. Your tip led me into the AC unit. Q101 looked OK.(by the way my ECG book lists ECG5645 600V 10A as a replacement). Checking further in the AC unit I found C153 22uf 25V capacitor on the PC board that is directly below the fan on the AC unit. Replaced the cap. and all 7000~ screws and the printer is happy. Hope this helps you!! Now if I can get lucky with my R40 Office Jet problem.
by Bob on Feb 15, 2004 at 3:35pm Add comment