Skycolor epson4720 head UV printer has problem of not supplying ink, which causes print head to not print patterns normally. This kind of failure is generally caused by negative pressure being adjusted too low to cause reverse suction, the secondary ink cartridge sensor is abnormal, and ink supply circuit is abnormal.
 
1. Too low negative pressure adjustment leads to back suction
 
If negative pressure value of Skycolor epson4720 head UV printer’s ink supply is too low, it will cause uv ink to suck back. At this time, ink cannot be smoothly supplied to epson4720 printhead. At this time, you only need to adjust negative pressure value on software to normal. If it is manual, it also needs to be adjusted manually.

It should be noted that: normal value of negative pressure of epson4720 head UV printer of different models is different, and there is no uniform range.

2. Secondary cartridge sensor is abnormal
 
Secondary ink cartridge sensor of Skycolor epson4720 head UV printer is abnormal, you need to check whether secondary ink cartridge sensor is sunken, if it sinks, just lift it up. If it sinks after repeated lifting, it means it is broken and needs to be replaced with a new secondary ink cartridge.
 
3.Abnormality in ink supply circuit of Skycolor epson4720 head UV printer
 
Check whether voltage of ink supply circuit of Skycolor epson4720 head UV printer is high and low, or whether circuit is burned out and short-circuited. If there are any above faults, stop Skycolor epson4720 head UV printer and repair the circuit.