SyntaxTerror

Once you mount the block onto the head, the screw and washer will keep both in place.

IIRC, there shouldn't be a risk of shorting anything on that side of the display. Also, the dibond panels are coated and would be unlikely to hard short anything. So I doubt it. Have a go at cleaning the connector. It doesn't take much to make a mess of the contact points. I've seen a single strand of hair lying across the contact surfaces screw up half the connections in one of these ZIF connectors. Fingers crossed it's something simple like that.

Yeah, a half ampere is far beyond what the microcontroller can deliver. But as you've got a laboratory power supply already sitting there for the 12V supply, it's really just a matter of: Finding a series resistor for the LED Finding a suitable switching transistor Picking a control line from the EXT connectors Using the M42 command - this time with a pin argument (as otherwise it defaults to controlling the LED pin) - to control the switching transistor If the diodes are 3.5V, 500mA (assuming you'll be using a single LED) and your supply is set to 12V, that means we'll want 8.5V across the limiting resistor. 8.5V / 0.5A = 17 ohms. The nearest E12 resistor value is 18 ohms which is close enough for rock and roll. It'll need to be able to handle some wattage though, as we're going to burn over 4W in it this way. That's of course just one example, using a single diode. We can modify things according to your grand master plan.

Aaand then I realised I forgot about the second part of your question. Right. I'm assuming for now that we're talking about some sort of relatively high powered LED here? The main board has quite a few spare outputs that we can play with - but the thing is that they're unbuffered, direct from the microcontroller. The ATMEGA2560 can only source 40mA on a given output (and that's an absolute maximum rating so you need to stay well clear of it). Which I'm guessing is not enough to power your LED. I'm betting you'll need to buffer the output with a transistor or similar current source. Don't let that scare you though.

Good to hear that you've made progress! And not to worry - we're patient people. Just curious ones as well For comparison purposes - which firmware version is your UM2 running? Edit: I can confirm that at least with Tinker firmware, the LEDs do not turn on when set to "always off" in preferences and then starting a print. Just tried it on my own machine.

Hah, my head is stuck in the past. I meant to say ON semiconductor.

The problem with integrated circuits such as these is usually that they're often made by a smaller, more specialized manufacturer that just can't deliver the volume of say, Texas Instruments or National Semiconductor. There's always going to be a risk of short supply. The A4988 is a current product and I've seen no end-of-life notifications anywhere, so they should still be coming.

They don't work. They're just something you look at before choosing to completely ignore them. And I think all 3D people with some hours on their printer have been there, haven't we? Myself, I've got several build plates so I can do a quick swap when a print is finished and keep the machine going. I'll be printing a bunch of PLA parts, then switch to ASA. And then completely forget that the build plate is now 85 degrees. I can always manage to remove it so I end up holding it before it registers that this is not something I should be holding without gloves. That's the story about how I invented 3D print/glass plate juggling.

Let me just take a moment to add that while the components are missing, the PCB remains the same (2.1.4). Meaning the pads are present. There's still the option of installing the missing components although because of the A4988 stepper driver, it will require hot air rework. So while there's a definite hurdle, it is certainly possible to get such a board up and running. Components missing from the PCB assembly are: Integrated circuit U13 Capacitors C69, C71, C75 Inductors L160, L161, L162, L163 Resistors R89, R90, R92, R98, R99, R103 Connector J31

Hold on, 5 12V fans? How are you going to pull that off with 24V?

Exactly. NEMA 17 is not a motor standard as most people think. It's just the the size of the mounting flange - 1.7" x 1.7". There's no specification of power/torque/length/speed/resolution/pretty much anything else whatsoever. So be careful there.

Have you looked at ApolloX? I have nothing but good experiences with that. It's tough as nails and resistant to just about everything under the sun. Including the sun.

Interesting! I wasn't aware of that. You learn every day In any case, if it can be swapped for a PT100 with a minimum of fuss for god's sake do it. They're just superior in pretty much every way for temperatures in our range. Plus they're a great deal easier to troubleshoot when everything goes wrong.

No worries. The display shouldn't be as problematic as a lot of other issues. As you've already tried replacing it, we can probably assume the display is okay (barring any overvoltage problems). Since you checked the ribbon cables to the main board as well we can probably rule out missing inputs to the board. It pretty much leaves us with: Power (13 + 3.3V) I2C data/clock input (main board microcontroller --> level shifter --> display) A reset discrete input

I was already typing

If you can find a multimeter, the first thing to do is check the display supply voltages (13V VCC & 3.3V VDD). The 13V supply is exclusive to the display whereas the 3.3V is used by the display, level shifter, SD card and knob LED (so I'm halfway assuming it might be fine). On the Ulticontroller board, measure (using TP9 as reference): 13V at TP5 3.3V at TP12 If those are good, I'd move on to inspecting the flex cable and connector (for the display itself). Those things can be horrid. If you have a microscope it's an invaluable tool for inspecting such things, if not a magnifying glass will do. Check the board connector for dirt and/or junk. Residue on the connector pins may not always be immediately visible and can cause havoc with zero insertion force connectors like this one. ZIF connectors are well and good, but they lack that little bit of abrasion offered by ordinary friction pins. So no matter what you do, get a bottle of isopropyl or denatured alcohol and a small, stiff-ish natural hair (say, pig bristles) brush. Cut off enough of the hairs that it gets stiff enough to scrub a bit. Dip it in the alcohol and brush the connector contact surfaces clean. Clean the flex cable fingers too while you're at it. Reinsert the cable, making sure it goes in perfectly straight and is fully seated. Lock the connector. Make sure the lock is fully engaged on both sides and that the flex cable hasn't shifted. Next, I'd probably move on to checking the level shifter, but this will require an oscilloscope. Got access to one?

I can of course only speak for myself, but when it comes to these things I'd chose buying from a reputable vendor rather than going with something that I just can't be sure of. It's all well and good when it works out, but considering the times when it doesn't... it's just not worth the few bucks you saved. Not even close. Quality control is not really something that a lot of these manufacturers are passionate about. If they even have anything implemented. So if it's a relatively cheap part, I'd get something I could trust instead. Every time. I do have a question though, out of interest? The UMO has a thermocouple instead of an RTD? I was operating under the assumption it was a PT100.

You pulled the connector off it? If you have a molex crimp tool, it's an easy enough fix. You'll need something like: Molex KK-254 housing Crimp pin

It looks like you have a defective PT100 sensor in your print head, most likely there's a break in the cable. If the break is close to the sensor, you can't repair it as it gets too hot for soldering. You'll need a new one. If you have or can borrow a multimeter, you can try measuring it. It's a PT100 sensor, so it's nominally 100 ohms at 0 degrees C. The alpha coefficient is 0.385 for most of these things, so at 20 degrees it should be around 108 ohms. If it measures correctly, try exercising the cable a bit at the hot end with the multimeter still connected. See if it intermittently shows open circuit. That'll be a broken cable.

Ultimaker does not deal directly with the end users anymore. You have to find one of their resellers - there's bound to be someone on that rather extensive list who will ship EU-wide. Probably most of them.

Well you had me wondering for a bit! And yes the Icelandic language has fantastic words for everything, since they stubbornly refuse to adopt any loan words. There are actual laws to keep such words out of the language. They prefer to figure out something new themselves. Hell, even such a thing as AIDS got renamed. No wonder "panda" didn't make it either

Not all warranties are transferable. The right to transfer warranty to another person will depend on whether it has been issued to you personally or whether it accompanies the goods in question. The terms and conditions should make this point clear, and in this case the warranty does not transfer to the second owner. You may still have the right to return the printer to the seller, though.

Also I'm going to get quite annoyed if I have to reorder boards with new silk screen

Yikes, someone charges 50 euros to replace an SOT transistor? I can certainly understand why you decided to learn! It's a useful skill anyway And I realise now it was both the PWM outputs. I was about to suggest you might have a bad kickback diode that might be causing it... but that would of course mean both of them, then. Hm. Anyway, another cause of it all might be non-constant load offered by a fan. The inrush current might be a problem. Anyway with the board I built I'm planning on doing some testing with a HEXFET equipped board very soon. I'm sure I can come up with a drop-in replacement part with performance far superior to the BC817. Just need to measure the PWM frequency from the main board again since I conveniently wrote it down and then apparently discarded the note.

I've been meaning to ask you about that, actually. I assume you've pushed them to around the max. current rating. Was it on the same board every time?