david ellwood
Kirabosi Kognoscente
Been meaning to properly write up the karik laser replacement for ages and just had one to do so I took pictures.
Heres the karik on its back.
1. remove the four case screws and slide off the sleeve revealing the mech.
2. now remove the small ribbon cables connecting the mech to the main pcb.
3. now remove the four screws securing the mech.
4. lever the mech out lifting the back first and pulling out of the front.
5. remove the two ribbon cables connecting the laser.
6. now turn the mech over and remove the plate holding the cd clamp (four small screws)
7. This allows access to the laser from the top. Next turn the two camlocks securing the laser transport bars.
8. Remove the bars and turn the laser through 90 degrees allowing removal
9. Here is a picture of the new hitachi laser next to the old pattern laser. Can you tell the difference?
10. insert the new laser and replace the bars and cables and refit the mech to the chassis.
11. now we turn on the machine and at this point it should play disks. attach a scope to the vrf point shown here.
12. here is a picture of the eye pattern before adjustment.
13. Adjust the laser output potentometer (mounted on the laser assy) for a level of 1.4V peak to peak (as shown here)
14. A this point i recommend the use of a cd alignment disk. This disk has errors deliberately painted on (the more tracks it plays the better the machines alignment)
15. Adjust the trimmer next to the VRF test point with a non magnetic trimming tool in order that the machine plays as many tracks as possible.
16. reassemble the casework.
Heres the karik on its back.
1. remove the four case screws and slide off the sleeve revealing the mech.
2. now remove the small ribbon cables connecting the mech to the main pcb.
3. now remove the four screws securing the mech.
4. lever the mech out lifting the back first and pulling out of the front.
5. remove the two ribbon cables connecting the laser.
6. now turn the mech over and remove the plate holding the cd clamp (four small screws)
7. This allows access to the laser from the top. Next turn the two camlocks securing the laser transport bars.
8. Remove the bars and turn the laser through 90 degrees allowing removal
9. Here is a picture of the new hitachi laser next to the old pattern laser. Can you tell the difference?
10. insert the new laser and replace the bars and cables and refit the mech to the chassis.
11. now we turn on the machine and at this point it should play disks. attach a scope to the vrf point shown here.
12. here is a picture of the eye pattern before adjustment.
13. Adjust the laser output potentometer (mounted on the laser assy) for a level of 1.4V peak to peak (as shown here)
14. A this point i recommend the use of a cd alignment disk. This disk has errors deliberately painted on (the more tracks it plays the better the machines alignment)
15. Adjust the trimmer next to the VRF test point with a non magnetic trimming tool in order that the machine plays as many tracks as possible.
16. reassemble the casework.