AOM driver repair - question for laser experts - Page 1
Forum section: electronics / repair

author: Redcat
author_rank: Regular Contributor
timestamp: December 12, 2013, 09:22:26 pm
content: Hi I'm looking for an expert who knows about AOM drivers from a minilab / photolab printer (like AGFA D-lab/Netlab, Durst Zeta,Kodak RP...).These AOM drivers control the AOM crystals ( simple said for laser beam modulation) in many of our lab machines.They now reach the end of their working life and many of them are already defective and I have no more spare to change.Sadly they are hard to get and very expensive, so we decided to try to repair them (desoldering and soldering is no problem, have done a lot).And here is where my question starts:All our AOM drivers are from "Crystal Technology" and are Type "207" or "407" (only one 407 - the 207 have sadly an older chip which is obsolete, maybe there is also an "307" laying around).I expect the amplifier chip Philips BGD714 (different number in Type 207 or 307) to be defective (but I am not sure).A friend of me is doctor of chemestry and worked some years ago with laser technology and I spoke with a friend of him from the laser technology center, but both could not really help me.--> The BGD714 is rated from 40 to 750MHz, would it be possible to exchange it with another chip (different part number BGDxxx) which is higher rated (and easier to get) to 800+ MHz?--> Can I put the BGD714 (or similar BGDxxx) into the Type 207?--> Would you, if you know these AOM drivers, also expect that the BGD714 is defective (these AOM drivers get very hot during operation, even with the whole case beeing metal with a big cooler). Or could it be something else?There is a 200 MHz oscilator inside, so I think it runs at 200MHz.I would have a scope that is capable to measure at this frequency, but I won't need to (and I don't want to blow my 475 to the moon), because I can clearly see in the printer maintanance software if the AOM diver works (and how good), because of the rising response curve it shows me (the 407 in the picture shows nearly a flatline).Have often changed the gas laser and plenty of AOM drivers and laser recorders in the last years, so I know my printers well, but I'm not an electronics engineer.It would be very nice, if someone could help me.Here are some pictures of the "407" Type:If you need more informations, I will try to give you.Nice greetings, Tom

author: yy482
author_rank: Newbie
timestamp: August 21, 2014, 01:40:20 am
content: we are using fuji and noritsu machine,we buy aom driver and laser gun fromchallenge-electronic.com,they can also repair,you can try.

author: Redcat
author_rank: Regular Contributor
timestamp: August 21, 2014, 03:18:39 pm
content: Thanks for your reply yy482.Of course we could buy new ones, and i knew 2 companies who sell them and i even knew the engineer who developed the printers (former leading engineer and trainer - but he won't/can't tell me) from Agfa personally, but it's too expensive for us to buy new ones.Earlier in the year i changed some of the defective chips to new ones, as i didn't get answers here. Now they do work again ok, but i would say not as good as new ones...maybe they need calibration?? (There is i think a trimmer cap inside.)So there is still the question open to an engineer who knows something about these special drivers, if i can hook an oscilloscope to it and calibrate it.Nice greetings, Tom