LCD Screen not showing up  

Re: LCD Screen not showing up

Double and triple check you've got the ribbon cables connected properly as they are really easy to muddle up!

Re: LCD Screen not showing up

If you press the knob the backlit goes off and the speaker beeps? It happened to me, and it was because I connected the cables upside down.

Besides what is stated in the manual about the cable numbers (one stripe, two stripes) you need to pay attention to the red wire in the cable, it should be on the top side.

Check this image from the manual:

Oops. 3DLight beat me. 😉

Re: LCD Screen not showing up

Yeah, on mine, the red lead goes to pin 10 at both ends.

Pins 1 and 10 are marked on the RAMBo; I think on the LCD panel, pin 1 is denoted by a white square around the solder joint; pin 10 is at the opposite end.

Peter

Re: LCD Screen not showing up

i am having this same problem but i have tried every possible orientation and still does not work

Re: LCD Screen not showing up

Those still with problems can you post pictures of BOTH the RAMBo mini with the cables connected AND the back of the LCD with the cables connected?

That way we can try and see if we can spot anything wrong.

Check the ribbon cables to see if you can spot any indication of a broken wire, it's rare on new cables but it can happen.

Re: LCD Screen not showing up

Hello! As for me, I experience almost the same difficulties with my printer I ordered this month. It's now been four times that I've checked the orientation and wiring of all my MK2 - everything fine. But when turning it on, the LCD makes a really loud, continous beep untill I turn the printer off. I wrote the support that I suspect a defective LCD (Since I had trouble with them when I designed and build my own printer a month ago) but they are different, so I don't want to change the firmware untill I get the original display to work.
Anyway, thanks for the possibility to post the wiring photos here, I really hope this can help me since it's quite a bit of money for a student to buy a printer like this...

kind regards,
Andrew

Re: LCD Screen not showing up

Hi Andrew

Your ribbon cables appear to be correct.

Have you checked the voltage of the PSU is set correctly for your mains supply?

The only other thing I can suggest to check the operation of the RAMBo/LCD is to unplug everything except the power supply and the LCD and turn on the power. If the LCD then works properly, plug in the other components one at a time, testing operation between plugging in the connector (switch off/plug in a connector/switch on/check LCD/repeat). Do this until the LCD fails, then you should have a clue as to what is causing the boot fail.

Obviously, if the LCD doesn't work with just the ribbon cables and power plugged in, then you have either a faulty PSU. RAMBo or LCD panel.

Peter

Re: LCD Screen not showing up

Hi Peter,

thank you for your time.

- yes, I checked the volage, it's set up correctly. Now the interesting part:
- I gladly tried what you suggested. It appears that the LCD is working without anything connected.
- I plugged everything in one step at a time, with switching everything off in the times between.
- After x-axis, y-axis, z-axis, x-endstop, y-endstop, heatbed heater, extruder heater, PINDA-Probe and extruder motor, I came to the heatbed-thermistor.
- The screen started showing weird things. I swiched off.
- Ok, I unplugged the headbed thermistor and carried on.
- Next, I plugged in the extruder-fan and swiched on. You can plug it in in only one direction, but after swiching on, the fan did not start spinning. I tried to help starting it, still nope. The display, however, showed the usual message of "this printer is not calibrated yet"
- whoa I thought, bad sign with the fan. But I carried on with the remaining connectors: Additional fan and Hotend-thermistor.

I did not get an error or a loud beeping as before, even with the thermistor of the bed now plugged in. BUT the Hotend-fan is now not blowing.

I wish I had my multimeter here, but where is the error now? And why is the hotendfan not blowing anymore.... 😐

kind regards,
Andrew

EDIT: Ok, I made the selftest and everything seems to be OK - During the test, the hotend-fan started blowing and turning itself off again. Is this common nowadays? (I am used to printers with the hotend-fan on every moment...)

Re: LCD Screen not showing up

Hi Andrew

The hot end fan only starts when the hot end has a certain Temperature..... I believe it was 50 °C.... or so 😉

Wild guess on the heat bed thermistor is that you have a damaged cable / connection which caused a shortcut
Do you get a reasonable Temperature shown for the Bed?

If yes you some how have (temporary) fixed that issue 😉
A closer look on the thermistor cable and connection might be a good idea.

If all looks ok you are ready to calibrate. Do you know which Firmware is installed?
You can check in the menu Service

All the Best
Frank
Edit: Ok Ok I see I am to slow to anser 😀
Good to see you are up and running!! Have fun with that beast. I love mine and it is almost all time running 😉

Re: LCD Screen not showing up

Hi Peter, hi Frank,

Yes, I am printing away already. You guys are my heroes right now. Thank you! 😀 I will keep an eye on that thermistor, but so far, everything is good.

thanks again and

kind regards,
Andrew

Re: LCD Screen not showing up

A thermistor short or O/C will not cause what you experienced, only MIN or MAX TEMP errors.

But it matters not, as long as the printer is working. Enjoy your prints.

Peter