Laser G not output.

[Westvill]

Hi expert. 

I have a problem when servicing 3201 Noritsu machine. The laser green light not outputing, and makes print out blocking green and fine magenta stripes. Check it on outputcheck, the frequency of polygon mirror is zero meanwhile R and B laser are 1380. Attempt to see the laser light visually by open the laser unit cover and got the green light appear but not the frequency or polygon mirror frequency is still zero. 

Try to replace aom driver, g laser gun and laser control pcb even the laser unit but the symptomp persist. Or didn't make any changes. 

Any suggest? 

Thank you

 

[Minilab service]

If you see 0 then can be not working AOM driver, G laser head, laser control pcb, or have bad connctions.

What is laser type - A1, B1, or Ff ? Can see it on software version check menu ( laser line ) . Also can write what are laser driver models.

To see how laser head works need to measure what is voltage between big resistor sides ( it is on laser driver ) . Resistor can be 0.1 Ohm , or 1 Ohm .

To see how works AOM need to look how many dots see after AOM crystal. Go to output check menu and turn on G laser. Before AOM crystal is one dot, but after AOM crystal should be few of them. When test need on top cover sensor put magnet ( software should see that top cover is closed ) .

[Westvill]

Thank you Minilab service. 

FYI, I opened the laser unit cover and performed output check to see green light. But in the PC's screen the frequency of polygon mirror = 0.

[Minilab service]

Here B1 type laser unit. What is voltage on driver resistor ( between sides ) ? Resistor is 0.1 Ohm and on multimeter need select 200 mV range.

How many dots you see after AOM crystal ( one , or few ) ? After AOM crystal put piece of paper, enter output check and start G laser. When test need on top cover sensor put magnet ( software should see that top cover is closed ) .

[Westvill]

Thank you Minilab service. 

Voltage between R 0,1 ohm is -5V. 

Laser light only one dot after aom crystal. 

What is your idea ti fix it? 

Here is I attach the print out. 

 

[Minilab service]

You need measure between resistor's  legs. on multimeter select 200 mV range. There will be voltage up to 100 mV . You have to measure voltage when minilab started and laser still cold and when laser preheated.

How many green dots you see after AOM crystal? After AOM crystal put piece of paper, enter output check and start G laser. When test need on top cover sensor put magnet ( software should see that top cover is closed ) . If there you see only one dot then AOM doesn't work ( AOM driver, AOM crystal, connection wires, AOM control from laser control pcb ) .

[kodak_service]

The head needs to be adjusted. There shouldn't be a bright green spot where it's highlighted in yellow.

[Westvill]

Hi experts. 

At last, I replace a brandnew laser G head and the result is exelent. 

The green light very bright and strong. 

Polygon mirror frequency = 1380.

Thank you all.