Y,Z end stops not working

Troubleshoot issues with the Little Monster
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Torgil
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Y,Z end stops not working

Post by Torgil » Sat Jan 20, 2018 5:49 pm

Need help with controller board which seems faulty from manufacturing.

Auto-calibration fails for me, after bed heats up LM pulls the extruder to end position. Only the X limit switch seems to work as that has the red LED lit and when the it reach the top motor stops and the LED is off. Y and Z motors tries to pull past the end-switch, it bounces a few times and auto-calibration aborts.

Measuring voltages on the connectors (see attachment) it seems clear to me that Y and Z connectors are faulty mounted (rotated 180 degrees), all connectors have 4.5V, 0V, and 3.2V on the same pins but Y and Z connectors are upside down. Limit switches work (tested by connecting all of them one by one with the cable intended for X).

I should probably get a new board from TEVO here but that may take a while (no mail answer either). However, I can easily rotate them to save time etc.

Can anyone here confirm from my attachment that Y and Z limit switch connectors rotated 180 degrees?
Two other connectors (see attachment) is mounted in the same rotation, should these be rotated as well (eg should all connectors have same rotation)?
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Redemptioner
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Re: Y,Z end stops not working

Post by Redemptioner » Sun Feb 04, 2018 11:49 pm

Yes, all should be voltage, ground, signal from right to left. Keep in mind there will be a 5V output for the signal on the one for the Z-probe (BL touch).

It is super strange for these to be connected up differently as they are set as traces on the PCB, you can try changing the pin layout on one of the connectors (just lift the tabs gently on the connector with an exactor knife), if this works then at least you will be up and running.

You won't get a response from Tevo, they don't care about or bother with customer service.
If it ain't broke then modify it

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Xerxes
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Re: Y,Z end stops not working

Post by Xerxes » Fri Mar 02, 2018 10:30 pm

It wouldn't surprise me if the pins were put into the connector out of order.. I've found at least one connector on my TLM where this was the case .. they'd used a black/red wire pair and crossed it over at the latching connector. In my case it was irrelevant because it was for the thermostat on the print bed...

Did you end up sorting out your issue?

Torgil
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Re: Y,Z end stops not working

Post by Torgil » Sat Mar 24, 2018 8:13 pm

I thought it'd be pretty easy to re-solder the connectors so I ended up doing that (clearing through-holes from tin turned out to be somewhat troublesome). Judging by the red leds on the end-stops they now work, however, after re-mounting the board and reconnecting all wires ...
1. the main power unit is now dead [applying 220V + switch on does nothing]
2. touch-screen is dead when powered with USB. Does this need full power?

It seems to boot though, led 3 and 4 are flashing, the rest are on, "Smoothieboard" turns up as a device on my laptop (Mac) and repetier-host connects.

If I skip the heat-bed, which voltages/currents are needed to power the board so I can verify that that everything works ok?
Any tip on trouble-shooting the main power unit?

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Xerxes
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Re: Y,Z end stops not working

Post by Xerxes » Sun Mar 25, 2018 7:23 pm

The power supply is 24V, and yeah the heated bed is 220V.

If the PSU doesn't turn on there is something wrong with it.. Maybe a fuse, but if a fuse blew there must be another issue potentially with how your smoothie-board is hooked up.

Unplug it from the wall and check the fuse holder on the back between the power switch and 240V input
You can prise out the fuse holder with a flat screwdriver (fairly easily). Conveniently there is a spare fuse inside the holder.

Then try unplugging it from the board and turning it on.
If you unplug the power lead in the smoothie board end it and look into it, the pins are labelled 1, 2 ,3 & 4.

There is 24.4V DC between pin 1 and 4 .. pin 1 is - and pin 4 is +

It appears on my PSU there is about 1V AC between pin 1 and pin 2, and also about 1V AC between pin 1 and pin 3.


If your PSU is not working I would contact Tevo for warranty replacement / support.

Despite what is reported by others, the last time I contacted Tevo for a support issue I got response fairly quickly.

The smoothie-board itself can be powered by the USB alone so you will see it on your PC when you plug it in via USB regardless if the PSU is working. The touchscreen needs external power, but you will see the red lights on the 3 x axis sensors, and red light on the bltouch probe as they are all able to be powered by the USB. When you initially connect the USB power you should hear the bltouch sensor go 'click-click click-click' as it starts up.

I have attached some pictures of how the wiring is plugged into the smoothie board on my printer (which is working.)

Looks like there is an issue in the black/white wire pair on yours in the picture you posted, the white wire appears to be connected to the wrong pin. On my board all of the female connectors for are facing the same way. Your picture shows four of them facing backwards! The screen print on my board identifies it as MKS SBASE v1.3 . I think you need to verify this with Tevo and have them send a replacement if the board has failed because of this! Just send them the picture you posted here.

Since you have taken to soldering them in the meantime, double check they are connected correctly now and check the fuse in the PSU.

Good luck with it... Let us know how you go
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