Blown Fuses - Hidden Shorts
Posted: Sun Dec 13, 2015 3:36 pm
Thought I would pass along a little experience in case someone else hits a similar problem.
Couple of months ago my printed just died with no fanfare. PS running, no Rambo, obliviously a blown fuse and since the logic is dead most likely the F3. Looked for problem with wires, connections, etc. and after not finding anything replaced the fuse and all is well. Sounds like a Finger of God type failure. Fast forward a month and the F3 blows again. Check again, VOM it death, no problems. Replace F3 all is well.
Well, actually something was wrong. Week or so ago F3 opens again and I had started noticing an occasional very slight line or shift in the prints usually just perceptible with your nail. Again go through every thing and no problems detected. It is now important to described the system. The hot end consists of an LED Light Ring, E3Dv6 with fan, three layer fans and a Yellowjacket Version 1 Quick Connect Board. It has been running daily for about a year in this configuration. Yesterday F3 opens again and it now is time to figure this out.
I had also noticed before the fuse opened, the LED ring would dim and blink very quickly and a layer shift line would appear. After fuse blew, I removed the hot end and disassembled it completely. Nothing seemed out of line until I removed the E3Dv6 from the Yellowjacket Quick Connect Board. Looking very closely at the contact area with the E3Dv6, the shoulder had worn through the varnish on top of the board revealing an unknown (to me) copper area. Apparently the E3Dv6 was shorting to this trace. But this was puzzling since that in itself wouldn't cause a short. Checking resistance through the hot end connections, one end of the wiring shows 3+ ohms resistance to the E3Dv6 body (cartridge resistance) and the other showed 0.0 ohms resistance, both should have been open. Unsoldered and removed the heater cartridge and one lead again showed 3+ ohms to the heater cartridge body and the other side showed shorted. So what I had was a heater cartridge with one lead shorted to the outside skin and another intermittent short developing due to wear between the board and the hotend body. When things were just right, a high resistance short developed pinging the logic and apparently generating the small layer shift and when a lower resistance or longer duration short occurred the F3 fuse opened. Real Finger of God type problem.
Replaced the heater cartridge with a spare and repaired/insulated the mounting board wear with a kapton sheet and the short to the hotend body is gone. Printer is now printing and has been running about 36 hours straight. No blown fuses, no LED blinks or offset (was starting to happen about every 10mm height with a blink and offset happening at the same time). May be a coincidence but there was a burn on the E3Dv6 at the same area as the bright copper on the board.
Went through a handful of fuses before finding the problem but I think this is now repaired.
gary
Couple of months ago my printed just died with no fanfare. PS running, no Rambo, obliviously a blown fuse and since the logic is dead most likely the F3. Looked for problem with wires, connections, etc. and after not finding anything replaced the fuse and all is well. Sounds like a Finger of God type failure. Fast forward a month and the F3 blows again. Check again, VOM it death, no problems. Replace F3 all is well.
Well, actually something was wrong. Week or so ago F3 opens again and I had started noticing an occasional very slight line or shift in the prints usually just perceptible with your nail. Again go through every thing and no problems detected. It is now important to described the system. The hot end consists of an LED Light Ring, E3Dv6 with fan, three layer fans and a Yellowjacket Version 1 Quick Connect Board. It has been running daily for about a year in this configuration. Yesterday F3 opens again and it now is time to figure this out.
I had also noticed before the fuse opened, the LED ring would dim and blink very quickly and a layer shift line would appear. After fuse blew, I removed the hot end and disassembled it completely. Nothing seemed out of line until I removed the E3Dv6 from the Yellowjacket Quick Connect Board. Looking very closely at the contact area with the E3Dv6, the shoulder had worn through the varnish on top of the board revealing an unknown (to me) copper area. Apparently the E3Dv6 was shorting to this trace. But this was puzzling since that in itself wouldn't cause a short. Checking resistance through the hot end connections, one end of the wiring shows 3+ ohms resistance to the E3Dv6 body (cartridge resistance) and the other showed 0.0 ohms resistance, both should have been open. Unsoldered and removed the heater cartridge and one lead again showed 3+ ohms to the heater cartridge body and the other side showed shorted. So what I had was a heater cartridge with one lead shorted to the outside skin and another intermittent short developing due to wear between the board and the hotend body. When things were just right, a high resistance short developed pinging the logic and apparently generating the small layer shift and when a lower resistance or longer duration short occurred the F3 fuse opened. Real Finger of God type problem.
Replaced the heater cartridge with a spare and repaired/insulated the mounting board wear with a kapton sheet and the short to the hotend body is gone. Printer is now printing and has been running about 36 hours straight. No blown fuses, no LED blinks or offset (was starting to happen about every 10mm height with a blink and offset happening at the same time). May be a coincidence but there was a burn on the E3Dv6 at the same area as the bright copper on the board.
Went through a handful of fuses before finding the problem but I think this is now repaired.
gary