Thermistor problems [Solved]

[noname117]

I recently switched to a E3D v6 hot end with a NTC3950 thermistor and edited the firmware according to this guide: http://matterhackers.dozuki.com/Guide/H ... +MAX+V2/25. However, when the printer is switched on, the LCD displays the message in the picture and I do not know how to fix it. Any help is appreciated

Solution:
The thermistor was shorted at the end and fixing this solved the problem

[Xenocrates]

Are you certain it's a NTC3950 thermistor? Could you go ahead and give me a look at both your hotend and the block around your firmware changes? I would also check to make sure that your thermistor isn't shorted (If it's one of the old style ones, without a cartridge, the glass fiber sleeving may not be in place correctly.), and that both the hotend and bed thermistors are connected (I hate that Repetier doesn't tell you which one is the problem)

[noname117]

Are you certain it's a NTC3950 thermistor? Could you go ahead and give me a look at both your hotend and the block around your firmware changes? I would also check to make sure that your thermistor isn't shorted (If it's one of the old style ones, without a cartridge, the glass fiber sleeving may not be in place correctly.), and that both the hotend and bed thermistors are connected (I hate that Repetier doesn't tell you which one is the problem)

According to the product page it is a NTC3950 but I don't know of anyway to visually confirm that. The only firmware changes I made was I changed "#define EXT0_TEMPSENSOR_TYPE" to 8 and "#define MAXTEMP" to 300. I am also certain that the problem is on the hot end thermistor since the bed thermistor was working fine before I changed the hot end. Attached is a picture of the hot end.

[Qdeathstar]

the issue isn't in the firmware. Any thermistor will send a signal back to the board, the firmware just translates the thermistors readings into a temperature based on what thermistor you chose. if you choose the wrong one, your readings will be off.

could be a bad thermistor or a short, you could use a multimeter to see what the resistance of thermistor is... it shouldn't be very low (eg 0) or very high (megaohms).

if it is very low, you got yourself a short. If it is very high, check your wiring for open joints, and if that don't fix it replace the thermistor.

[Nylocke]

That isn't an E3D V6, unless they changed the design a whole lot. Where did you buy your hotend from? It should be longer (more rectangular), and E3D uses dots to "code" the nozzle size, they don't actually etch the number into the nozzle. They also recently switched to cartridge temp sensors, so no need to mess with sleeving (and if you got an older one it should've had fiberglass sleeving, not teflon).

[IMBoring25]

The heater block aspect ratio doesn't look completely off to me, allowing for possible distortion of the lens, but the engraved nozzle size and clear thermistor sleeve are definitely goofy and suggestive of a clone.

[Xenocrates]

The heater block dimensions aren't entirely off, but the lack of a chamfer does point very strongly to a clone. If you paid more than 30$ to the seller, return it, especially if they represented it as an actual E3D hotend. Instead, buy from E3D directly(UK based), Filastruder (US), Matterhackers (California), or any of the fine companies on this here list: http://e3d-online.com/Genuine-Check Say no to clones. The hotend is on of the biggest factors in your print quality, it makes zero sense to buy a 1k$ printer and then cheap out too much to buy a 30$(E3D lite) to 70$(E3D V6) hotend that a company will actually stand behind and help you with.

[noname117]

I realize this is a cheap knock off which is why I didn't spend much money on it. If it works I saved some money if it doesn't I don't lose much.

[noname117]

the issue isn't in the firmware. Any thermistor will send a signal back to the board, the firmware just translates the thermistors readings into a temperature based on what thermistor you chose. if you choose the wrong one, your readings will be off.

could be a bad thermistor or a short, you could use a multimeter to see what the resistance of thermistor is... it shouldn't be very low (eg 0) or very high (megaohms).

if it is very low, you got yourself a short. If it is very high, check your wiring for open joints, and if that don't fix it replace the thermistor.

The problem was that the termistor was shorted at the one end. I fixed this and now it is working fine. Thank you for the help