Need Help Roland SolJet Pro XC-540 Blown Fuse I think

OL stands for open loop so its not connected or blown ??

 

Hi Glenn - I think that, if you are getting an OL on your meter when testing the fuse, it is likely blown. Especially if you are testing the other fuses and they appear good. I would test the next new fuse with your meter before you install it. Make sure it reads properly. Then check it again after you install it to make sure it isn't blowing again.

Couple things about those fuses - they exist to protect your print heads from potential damage from the circuitry. However, they don't necessarily work the same way in reverse. So if you have a short at your print head/carriage board or ribbon cables, it could possibly blow one of those fuses, but it could also damage the Head Board in the process (blown transistor). Testing this can be tricky, but the easiest way is to install a fuse, and then check it after the machine has been powered on. If the fuse blows right away, then you are looking at a short circuit somewhere upstream from the head board (print heads, carriage board, etc). Start looking for damaged cables, ink buildup on the heads or carriage board, stuff like that. Also, if you find damage in those components, it may have caused a blown transistor on the Head Board. You may want to have that board tested by checking the transistors.

This is usually a challenging issue to chase down and can get expensive if you keep blowing head boards. So, it might be worth considering bringing a service tech in to help troubleshoot.

Hope this helps.
Scott