PTR-4100 RH problem

[ChrisZ]

Hello.
I have weird problem with PTR-4100 16ch mfg 2004.

Machine was reporting laser driver LD1 error time to time. Customer was able to expose plates by using lasers 0-7
After some time machine started to report LD3 error. Now we are unable to calibrate lasers.

Weird thing is than when I do laser power measure it shows power as on attachement while Iopd-Iop looks as on second picture.
When I perform laser power measure couple of times in a row sometimes it shows ch6 and ch10 0mW

What I did so far:
1. Checked power supply voltages under load. OK
2. Replaced cables X810 and x801.
3. Swapped driver boards.
4. Cleaned the optics, laser power sensor.
5. Swapped laser diodes 10 with 15. Machine was reporting that #10 got 0mW before and after swap.
6. Checked parameters od LD boards, Iop, looks normal.

I'm running out of ideas.
Is there anything more I can check to fix that machine?

Regards, Chris

Images on the way

 

[aligh]

hi
what is error on ld3?what is error in ld1 ?if have error on ld 1 can not work in ch1(0-7)
as i remember check ld3 in laser power confirm not zero. this is good reference for each ld .it show situation of ld .
regards

 

[ChrisZ]

Ld1 and ld3 too high current.
Chris