CTC HBP not working

[Eduardo_Garcia]

Hi,

I have a ctc and my motherboard burned out. I bough a new one and everything works, except my temperature reads from the extruder thermocouples are not accurate. They read 180c, but its actually at around 230c. If anyone knows how i could fix this, that would be great. The main question though is that after i installed my new motherboard, the HBP does not work and it says temperature failure and N/A for temperature. I thought it was the thermistor so i bought a new one but still nothing. I ohmed out the original one and it ohms out at 106k at room temp which is ok, so i ruled that out. the 2 resistors both ohm out at 102 and 472. So the only thing left is the capacitor. Does anyone know what is the cap value for it? I am assuming the capacitor burned out when the MB burned. Does anyone have any idea what else it could be? thanks

[iCloud]

I know the motherboard on the CTC machines uses a 100k thermistor in a resistor bank and that if your board reads NA or not readable or something like that while it’s connected you have burned a trace on the board

[Eduardo_Garcia]

The mb is brand new. Do you mean burned a trace on the heated bed?

[adamcooks]

What killed the old board? Simply plugging in a new board into an existing problem, generally kills the new board. Thermocouple’s are not inaccurate, they are generally mounted incorrectly. Is the tab in the same place? is the replacement tc electrically isolated from the tab (many many cheap tc’s on eBay are not.

[iCloud]

Yes sorry autocorrect messed up and the trace may have burned the board and that’s why your new board can’t read a heated bed becuase the bed blew up and took the motherboard with it so when you plugged in your new board it’s not blowing up because the board is dead possibly

[Eduardo_Garcia]

I’ll check the bed trace for continuity.

[Eduardo_Garcia]

I accidentally shorted the thermocouple with the 24v of the heater cartrige. That burned the the voltage amplifier in the mob for that thermocouple and numerous other components in the mb. I replaced the mb and got 2 new thermocouples for the extruders from maker geek from maker geek. The mounting is the same as the old thermocouple. I don’t know if the bed got messed up when the old mb burned, but that was my assumption that the cap or the thermistor got screwed up. I am not totally sure how they would mess up though since the bed circuit an extruder circuit look to be isolated from each other by what I can see in the mighty board schematic.

[iCloud]

I have loads of parts for these machines if you need any a replacment heated bed di think are around £40 and they are flahsforge style so they read properly straight away and don’t require changing the thermistor, and if you touch any two positive and negitive wires on these machines the board blows as there is no diode back protection

[Eduardo_Garcia]

Yeah, that’s how I blew the first mb. I am trying to fix my bed though, are you saying it’s broken beyond repair? Can I test the connection on the connector and see if I am getting proper voltage from the motherboard? Or will this fry my board? I know if the motherboard gets no read from the thermistor it will not turn on the 24v to heat the bed. But there should still be voltage coming into the Bed from the mb into the thermistor circuit.

[iCloud]

If you get a thermistor stick it in the red and yellow connector wires on the heated bed connector on the right hand side of the connector and the connect the multimeter to the red and black wires and turn the machine on the bed will read like 150+ °c and turn on the heated bed and that’s the quickest way to measure the voltage

[Eduardo_Garcia]

Thanks. I’ll try that tonight and post back.

[Eduardo_Garcia]

So I just did this and I got no voltage from the red and black wire. I am guessing that means my motherboard has something wrong.

[iCloud]

Was the printer reading the thermistor over what you set it ? I remembered that you have to get it to read below 130°c before the heated bed turns on and I think your board is blown not your new motherboard

[Eduardo_Garcia]

I did what you said to connect a thermistor and try and measure the voltage. I got no reading on my meter. I have homed out the bed though sig and ground and I get 57k ohm. It drops in resistance when I heat it and increases when I cool it. That leads me to believe the bed is ok and my mb is not sending out 5v to the bed. I’ll trace it back to the mb and see if it I can get a 5v reading.

[iCloud]

Have you checked the wires for any damage but also the 5v source is just for the LED isn’t it? Shouldn’t affect the function of the bed but when you put the thermistor into the connector what did the printer read?

[Eduardo_Garcia]

I thought te thermistor circuit ran on 5v, that’s besides the point. I did exactly what you said, I connected a thermistor directly to the connector, red to yellow then I turned on the printer. It still showed NA for temperature. If by doing this is supposed to read 150 then my mb has to have something wrong.

[iCloud]

I did this by accident once I switched of the heated bed option in replicator g and forgot and my printer said NA for build platform temp if you plug the machine into rep g flash sailfish on to it and selected bhp installed to yes and plug in your heated bed the. It should read it

[Eduardo_Garcia]

This sounds like it could be that. I did flash to sailfish. I’ll try it tonight. Thanks for all the help.

[Fayaz_Choudhary]

CTC has very bad extruder design and also they have USB key so you can not use generic filament after every filament roll they are forcing you to buy another USB key and often during the print it will stop false error will come up Roll INv. means change USB key. more then half the jobs dissenter extruder need major update
also CTC filament is so fragile that it can break during any print job so its very hard to complete the print one another always some problems are there.

[Eduardo_Garcia]

Mine does not have a USB key. My printer works great except for the mentioned issue with the hbp