Laser Diode for Panasonic Copier

Dario wrote in news:446b4a6d$0$47023$ snipped-for-privacy@dread15.news.tele.dk:

Got any part numbers or specifications?

Dario wrote in news:446b524d$0$47073$ snipped-for-privacy@dread15.news.tele.dk:

Diodes at intellite.com and roithner-laser.com might fill the need, but there are many things to watch for. One of the easiest is solving different pinouts, but you'll need to know if there is an internal photodiode that is wired for in your circuit, and also things like the mode, (and if multimode, the 'stripe width'). By far the easiest way to be sure is to identify the diodes and get specs for them. Replacing laser diodes with a near-equivalent is a far more risky business than doing it for transistors. What you need most is probably a way to convince Panasonic to tell you. Maybe you can get a schematic for the assembly that directly connects to the diodes, and that might tell you.

You might get some help from online references to the way the copier uses lasers. I had a quick look but didn't find much. I also don't know enough about the machine to know how to narrow the search usefully.

Thank you so much, We bought the serice manual, it has all the schematic diagrams (almost

Lostgallifreyan wrote:

Dario wrote in news:446d963d$0$46984$ snipped-for-privacy@dread15.news.tele.dk:

One way is to post in alt.lasers as you'll probably find someone there who has serviced them before. I think you're right about single mode, at that power range, and the wavelength might not be critical. If you can look closely at the front of one, see if it looks like a simple 0.3 mm thick window with a tiny chip behind it, or if there is any kind of microlens or other optic as part of the canned diode assembly. The more detail you can give of anything like that, the better, and other detail of the optics path might help too, what sort of optics, etc... I think you'll be ok with a simple and cheap diode though, but my thoughts aren't as useful as what alt.lasers might offer.

One good possibility is that many of the likely diodes are cheap, and you could maybe afford to try a few. The photodiode should have survived, and you can test for that as for any photodiode, if you know the existing diode is dead, there's no risk in trying less than careful tests on that. That would give you the right pin for ground and photodiode, plus polarity, narrowing the search for a right diode a lot. Even a dead LD might also give you the polarity to give the exact pinout. If you find you've got an unusual pinout, the chances of identifying the diode improve hugely.

Just curious, how do you know that the diodes are the root cause of the problem and not the driver circuits burning out the diodes? Replacing them might just result in another burned out diode...