beginners problems: connection and heating problem?

[JohanJonker 2]

Hello everyone

I am new in this forum. Since a few days I have a used Ultimaker Original that was really cheap because som parts were missing. I completed most of the printer now but I encounter some problems.

When I start the system the displat shows this:

T434/0

X 0 Y 0 Z 000.00

FR100% SD---% o--:--

Err: MAXTEMP

The display is on about 5 seconds and then one second blanc screen.

The lower fan starts very noisy bu after a while it is OK.

I think it does not have the original Arduino Mega 2560 print. I had to download a special driver to get it working.

I use a windows computer that shows this port when the Ultimaker is connected. USB SERIAL: CH340 (COM6).

In Cura I have to set the comport to COM6 instead of auto. The update of firmware is OK. It reports something of Marlin 250000.hex.

However when I want to run the bed levelling wizard - and connect to printer it cannot make a connection to the printer.

It would be nice if someone could help me with this.

kind regards

Johan Jonker

This link show what I want to do with this printer (sax)

[gr5 2,268]

You have a display. That's great. That means you don't have to print through USB (which is more difficult).

MAXTEMP is probably the most serious issue here. Something is wrong with the temp sensor. There should be a green terminal connector on top of the print head that has 2 screws and 2 wires going to it. Check that the wires aren't loose. The temp sensor is a bit complicated - there is a thermocouple inside the print head. The 2 wires for that go up to the tiny circuit board on the print head and get converted to a voltage. I hope you are good with electric circuits or there is someone you know who can fix very simple circuits. The output voltage of this tiny board is 0V to 5V where 0V=0C and 5V = 500C and linear in between. So at room temperature it should be about 200mv.

If that is at the correct voltage then it probably is not connected properly on the circuit board underneath the printer.

[gr5 2,268]

It may be that cura won't be able to connect until you fix the MAXTEMP problem.

[JohanJonker 2]

Thanks gr5 (nice logo)

You are right. When I remove the connector of the thermocouple. The display says Ultimaker ready. And I am able to connect to the computer also.

I measured the output voltage of the sensor and it was 0V (in fact much less than 200mV) and remains that when it is getting warmer. So I think I have to replace that. I already removed it from the heater block (that wasn't easy). Now I wil try to find a new one.

Thanks for helping.

kind regards,

Johan

[JohanJonker 2]

However, the problem can have more causes:

1) the thermocouple

2) the small thermo interface board

3) the connection with the board

When I disconnect the thermocouple from the board it says Maxtemp

When I disconnect the connection betweer the thermo interface board and the Ramps board it says that everything is OK.

How can I check the interface board?

[JohanJonker 2]

OK that last one was a good idea: the connection. Why didn't I check that before? It appeared that as well the black and the brown wire are broken. When I connect them there is something new on the board: a blue light! Yes and a temperature of 19 degrees (Celsius)