This was a real problem for me ended up changing the UV lamps. Originally was very fast, and printing with Rasterlink only needed 6 passes @ 100% UV illuminance. Then after 6 months it suddenly stopped working and I couldn't get adhesion on the white ink. After checking & doing everything else - running a humidifier, fresh ink bags ($$$), using Red Hot or AP3155 promoter with no dilution, full head cleaning, new wipers, several white maintenance runs, etc - I had to dial it up to 12 passes. This was ok enough but slowed production down.
Then 4 months later the same problem happened. It had to be bumped up to 24 passes @ over 100% UV illuminance + extra passes to get white adhesion. Very slow! I figured the UV lamp was going bad even though it says it has 1300ish hours on it.
There is UV lamp test function on the printer but the test kit "OPT-J0250 UV-LED ILLUMINOMETER KIT ASSY" is something like $2,000+ when I found it for sale. And I don't know the reference values anyway. It is just a Hamamatsu Photonics C9386 UV meter if anyone cares to buy one.
I hate to just swap parts on stuff without diagnosing fully, but I took a chance and replaced the UV lamp (not the whole assembly or board) I got from TD Digital here at signs101. It worked fine again at 6 passes. The light coming from it was significantly brighter too. If you've ever swapped tubes on a water cooled laser engraver it's just like that - you're used to it's brightness on the undercharged tube, but then put a newly charged one in and it's like a supernova exploding lol - same deal here.
Here's a photo of the old UV lamps first, then the new ones. I am not sure if it's a new model or design because some of the gold trim is engineered differently, but the old/bad UV has physically smaller lamps. Did they burn out or something? Who knows. If this fails again I think the next step is replace the PCB in the lamp assembly, there are some gnarly looking transformers on it that could go out of spec.
Then 4 months later the same problem happened. It had to be bumped up to 24 passes @ over 100% UV illuminance + extra passes to get white adhesion. Very slow! I figured the UV lamp was going bad even though it says it has 1300ish hours on it.
There is UV lamp test function on the printer but the test kit "OPT-J0250 UV-LED ILLUMINOMETER KIT ASSY" is something like $2,000+ when I found it for sale. And I don't know the reference values anyway. It is just a Hamamatsu Photonics C9386 UV meter if anyone cares to buy one.
I hate to just swap parts on stuff without diagnosing fully, but I took a chance and replaced the UV lamp (not the whole assembly or board) I got from TD Digital here at signs101. It worked fine again at 6 passes. The light coming from it was significantly brighter too. If you've ever swapped tubes on a water cooled laser engraver it's just like that - you're used to it's brightness on the undercharged tube, but then put a newly charged one in and it's like a supernova exploding lol - same deal here.
Here's a photo of the old UV lamps first, then the new ones. I am not sure if it's a new model or design because some of the gold trim is engineered differently, but the old/bad UV has physically smaller lamps. Did they burn out or something? Who knows. If this fails again I think the next step is replace the PCB in the lamp assembly, there are some gnarly looking transformers on it that could go out of spec.