Magnus 400 Laser Diodes go crazy

[ameyer]

Dear Forum,

i have a problem with the laser diodes in my Magnus 400 or - to be precise - with the software controlling them.

Once a day (or twice) the Software notices 1-4 diodes not valid (diode 12, 20, 16, 18). After resetting these diodes and rebooting the machine everything may work fine to a certain time.

The values of the diodes are around 480-500 mA the whole day. When the diodes are reported bad, all diodes use approximately 150 mA more and 1-4 are above 767 mA and invalid. After resetting the diodes it's possible that they work fine or that you have to wait 1-2 minutes until they work again. There is no scheme to be seen.

I cleaned the small calibration window four or five times last week to make sure there is no dust on it.

I called Kodak once and a technician resetted the diodes from the registry via VNC. That seemed to be more efficient as the software didn't report an error for a month or two. He also said that the diodes are not really broken.

If anybody here knows how to reset the diodes from the registry or another way to avoid these creepy messages i would be very thankful for any advice.

Andreas

ps: Sorry for my bad english :-(

 

[nemo]

the diodes are calibrated before each plot - diodes failures may have multiple causes - diodes going weak, dirty lens, bad light detector, carriage losing steps and many others.
You can reset the diodes yourself through the laser group dialog.
Run a calibration several times - if you see some diodes consistently drawing a high current a temporary fix will be to reduce the power and drum speed proportionally 10-15% should be enough but eventually the diodes will need to be spliced to spares that you have in the laser.

 

[ameyer]

hi nemo!

thanks for your answer. my problem is that the diodes are not weak, the lens is clean. i once called a technician from kodak and he said that resetting the diodes through the laser group dialog would not really work in my case and that he has to reset the diodes through the registry. which he did. and i didn't see how he did it. but after that procedure there was no error message for the next three months.

in the last three days after posting my first post i made 130 plates without any error message.

if only one diode would be bad i would agree in saying that it needs to be spliced but if the error occurs four or five diodes are reported bad and the other (healthy) diodes are much more power consuming (+150 mW) than before.

so i think it's a software error or so. i dont think that the diodes are able to heal themselves ;-)

if there's any further advice i would be very glad to hear.

thanks in advance

Andreas

 

[nemo]

From application or registry should be the same - in registry you can manually reset the first and last laser active and expose laser active values. Or you can make a registry backup of the branch and run it when it fails.
Initially you said you cleaned the "small calibration window" - that is the light detector I guess - I'm talking about cleaning the optic laser lens.
The problem may have many causes. The carriage may be losing steps too while moving towards home and not going in the correct position for the light detector. Next time it's happening try to initialize the carriage before resetting and recalibrating. The light detector position and also be adjusted in registry +/-0.5-2mm.
Again - while your machine is running fine, run the calibration at required power a few times and watch the current value for the diodes usually failing - if it's constantly higher than the others they are getting weak and you can either reduce power/drum speed or splice the diodes to spares.

 

[PACH]

I wonder if it could be a cooling problem.?!? OR an intermittent problem with the IALDA card?

Dear Forum,

i have a problem with the laser diodes in my Magnus 400 or - to be precise - with the software controlling them.

Once a day (or twice) the Software notices 1-4 diodes not valid (diode 12, 20, 16, 18). After resetting these diodes and rebooting the machine everything may work fine to a certain time.

The values of the diodes are around 480-500 mA the whole day. When the diodes are reported bad, all diodes use approximately 150 mA more and 1-4 are above 767 mA and invalid. After resetting the diodes it's possible that they work fine or that you have to wait 1-2 minutes until they work again. There is no scheme to be seen.

I cleaned the small calibration window four or five times last week to make sure there is no dust on it.

I called Kodak once and a technician resetted the diodes from the registry via VNC. That seemed to be more efficient as the software didn't report an error for a month or two. He also said that the diodes are not really broken.

If anybody here knows how to reset the diodes from the registry or another way to avoid these creepy messages i would be very thankful for any advice.

Andreas

ps: Sorry for my bad english :-(

 

[ameyer]

Dear nemo, dear PACH,

first of all i want to thank you for your interest in my problems. I do not take this for granted and i'm very thankful.

@nemo: i already adjusted the light detector position with no effect. How do i clean the optic laser lens? I guess it's located on the carriage. I'll look tomorrow when i'm back at work.

@PACH: Do you mean a cooling problem with the computer working in the Magnus? A cooling problem with the laser diodes would be reported with an error message!? The IALDA card is one thing i never noticed in the Magnus. I'll take a look tomorrow at work. What does this card do?

 

[PACH]

The IALDA driver has many functions:
*laser calib at the start and end of every expose
*laser uniformity
*edge detection
*switches laser On and Off
*controls laser intensity
*reports on Chiller status and IALDA head temp etc.

Mind you, you will get banding with a problem with the IALDA driver which you do not have.

Dear nemo, dear PACH,

first of all i want to thank you for your interest in my problems. I do not take this for granted and i'm very thankful.

@nemo: i already adjusted the light detector position with no effect. How do i clean the optic laser lens? I guess it's located on the carriage. I'll look tomorrow when i'm back at work.

@PACH: Do you mean a cooling problem with the computer working in the Magnus? A cooling problem with the laser diodes would be reported with an error message!? The IALDA card is one thing i never noticed in the Magnus. I'll take a look tomorrow at work. What does this card do?

 

[ameyer]

Just one more question as you seem to know a lot about lasers and the Magnus.

Will the lasers live longer running them on lower power consumption? At the moment the drum speed is set to 670 rpm with a laser power of 150 mW. I thought about letting the Magnus run with 400 rpm and 90 mW power consumption - if this would have any effect to the lifetime of the lasers.

 

[PACH]

The answer to your question is YES, but you are already running the lasers at a low power. Some places the lasers are set at 300mw using process-less plates.

Just one more question as you seem to know a lot about lasers and the Magnus.

Will the lasers live longer running them on lower power consumption? At the moment the drum speed is set to 670 rpm with a laser power of 150 mW. I thought about letting the Magnus run with 400 rpm and 90 mW power consumption - if this would have any effect to the lifetime of the lasers.

 

[ameyer]

So i'll leave the power at 150 mW and see what happens next.



Thanks!

 

[ilker]

Hi,

Pls do following steps

clean the lens
clean the light dedector glass
clean the filter of the d-box
clean the 5 volt power supply of the power supply box
change POSITION OF THE LIGHT DEDECTOR ın the gui

 

[ameyer]

Hi ilker,

thanks for your advice.

Luckily the mistake last occured at 29/09/2013.

I cleaned the lens and the light detector glass and changed the position of the light detector.

Since then im looking at the values after each plate and they are stable between 395 to 497 mA.

Thanx

ameyer

 

[ilker]

Ok Ameyer,

good.

If you have a problem you can write me

 

[ameyer]

Thank you for your offer!

ameyer