Welcome to the SeeMeCNC Community

hi everyone, ive a problem...

delta H2 printer, latest firmware, mattercontrol, windows 10 systems.

this printer seems to be working good when it works, my issue is it doesnt heat up, it doesnt begin the heating process? intermittently...
this happens when i try manually to heat up the hot end via the lcd or thru mattercontrol 'preheat' and 'print' commands.

test 1: i put a heat gun to the hot end, and the temp does indicate the temp of the hot end it going up, on the lcd, and in matter control.
test 2: i took the he280 hot end out, and did a brief ohm continuity test on the resistor on the hot end, (i did not un-solder it from pcd or other end, but unplugged ptr, etc.. ) i put the test leads on the end wires of the heat resistor, shows 0 resistance, so it looked good.
the red light on the mini-rambo for the mofset extruder heat comes on when heat is called for... also a little red light on the pcb he280 accelerator board comes on (as well as the 2 blue lights already on).

then i can wiggle the whip wire a bit, tug it a little in a unknown direction, and it will begin heating up properly, then if i print, i get the 'decoupled error'
so i assumed the whip wire (8-pin connector) was coming loose.. i tried a few of the 'whip clips' to print but they didnt seem tight fit enough, so i got an 8-pin 'locking' connector (http://www.themakerhive.com/shop/viewit ... oductid=39) it seemed did the same thing, heated up, printed once or twice, or with print decoupling error, and also needs wiggling...

when i just goto print, and wait, i get the 'NOZ: def' and 'heater decoupled' error/situation.

i have cleared theeprom, reloaded the firmware, g29, pid.
i have taken the 8-pin connector wires out, and cut them even, re-stripped the end a little bit, and put back into the connector, i even used a little safety pin tip to go 'into the hole along next to the wire' to open up the 'whatever tightens on the wire inside' the connector, so that i got a good fit into the connector (then pull out the safety pin, and leave the wire end in tight to fit...)

so, im thinking... it could be:
a. still the heat resistor on the hot end, although it looks like it tests with full continuity, i didnt un-solder it and test it 'alone'.? i think this because all i looked around and saw this error, and this result on the lcd after a print or preheat attempt, all forums said it pointed to the heat resistor on the hot end.
b. the hot end itself, the 8-pin connector mounted on the pcb accelerator board...?
c. maybe my hot end is just not installed securely, maybe i need to take it out, open it up, un-solder the ends, and then cleanly re-solder all the connectors for the hot end assembly?
d. i dont think its the thermistor, as when i use the heat gun the temp goes up, so (if im correct...) that is working properly, and sending signal to the minirambo properly...)

thanks again for any help resolving this, i just printed the 'whip clip, that has the 'full round cover for the hot-end..that clips it in place, but its basically the same a s the 8-pin connector with clip i installed.. its not 'coming out' of the 8-pin mount, it is secure, but somewhere its wrong, loose, not right..
i still very new to this, newbie, and especially new with using the multi-meter to test items... (l saw how to test the heat resistor on youtube video meant for dryer heat-resistor, but thay said the test is the same for 'all' heat resistors... )
the wiggling the whip a bit isnt working anymore, and i dont want to pull it too much to get it going...

marc

To summarize, there is an intermittent issue with the hotend not heating. You've tested the thermistor for function (Heat gun causes rising temps). You also have checked the "heat resistor" (Is this the Thermal fuse in the heatsink, or the ceramic cartridge in the nozzle block?). You've reterminated the hotend end of the connection repeatedly.

Some steps to check:
Check the controller side connections, both into the mini-rambo (Should just be the output, as the input failing would knock the whole controller over since the mini shares that input between logic and heat).
Make sure the LED's light up, indicating attempts at heating by the controller.
Check whichever of the "Heat resistor" candidates you haven't already.
Check for pin wear/obstruction in the connection (bits of fluff/insulation, ETC).
Replace the entire heater wire run.

thanks! yes, the red light on the mini-rambo indicating the heat signal is received is on when i either 'preheat' in matter control, or 'adjust/set temp' on the lcd.
i did in fact check/tighten the red/black wires going into the minirambo mofset for the extruder, i tightened them up.

so, tuesday night (im flipping this thing on its top and going to check all the connections on the bottom going to the minirambo, opposite end of the 8-pin.
ill check for fluff/and obstruction. ill also order another heater wire run, i think seeme has one already all soldered up on the one end, and 'properly inserted into the 8-pin)
thanks for the time and the suggestions, it also lets me know that i was indeed looking at some of the correct points while troubleshooting, which is part of the learning process i guess.
marc

basically it was the heat resistor in the hot end, although it multi-tested at 0, after putting in the replacement heat resistor and rebuilding hot end, it works fine, heats up on command now.