Bringing Fried M2 Back from Dead

pyronaught · Post by **pyronaught** » Wed May 18, 2016 4:51 am

So I bought a new Rambo board from MakerGear to replace the one I fired a few weeks ago. I'm having issues getting it to work though and have no clue how to troubleshoot this thing. Here's the current symptoms:

- When I power up the M2, the two fans connected to Fan1 (extruder fan and rambo cooling fan) turn on at first, then after a few seconds they turn off and then never turn on again.

- With M2 turend off, when I plugged in USB cable for the first time, the computer saw it and installed the RAMBO driver. This is not a problem, just saying that part worked right.

- With USB cable connected prior to turning on M2, after turning on M2 S3D can not connect to it when choosing the correct COM port and clicking Connect button. If USB is disconnected when M2 is turned on, then plug USB cable in afterwards, S3D sees it and connects to it automatically. I have four other M2s in the room and none of them behave like this, so it's not a cable issue, incorrect port or S3D setup issue.

- When connected, X and Y jogging works but trying to move the Z axis up doesn't work. Platform can move down, but not up. It's almost like the motor doesn't have enough power to move it up, as it makes noise and struggles but there's just a grinding noise and the platform actually slowly drops. Going down is no problem though and sounds normal. The platform seems much harder to manually push up than it used to be and sticks in places. Maybe a bearing issue? Was working fine before I fried the Rambo board though.

The Rambo has the firmware for the latest M2 on it and I did not change the firmware. This M2 is one and a half years old, did anything major change that would effect connectivity or the Z motor? I did not want to add another potential problem by changing the firmware until after testing that the basics are working out of the box.

Jules · Post by **Jules** » Wed May 18, 2016 5:54 am

Is it possible that the Rambo board has the Rev.E firmware loaded on it? That probably wouldn't work too well. (It's actually reversed, with the Z-stop on the bottom.)

BTW: The Rev.E firmware does turn the fan on for a couple seconds on connection, then turns it off automatically. (It also shuts off the extruder fan automatically when the nozzle cools off.)

The more I think about it, the more I think you've got the wrong firmware loaded on the Rambo. Couple other folks reported something similar with the grinding a few months back.

thunderbt3 · Post by **thunderbt3** » Wed May 18, 2016 1:07 pm

The latest firmware you loaded onto the Rambo is the Rev. E firmware for the 4 point spider leveling and the z axis home switch at the bottom. Fans should power up a couple seconds when power is turned on and then will turn off. Once the hot end reaches 50*C, the fans will kick on again. The latest firmware also is for the all black Z motor. Steps/mm are different and Z axis direction between the all black Z motor and the silver and black z motors that the older M2's have. I upgraded my M2 with the beta Rev E. and had the beta firmware on it. I have since upgrade to the latest firmware. Since I'm running the older silver Z motor, I went into the firmware and manually changed the Z axis steps/mm to 400 and then reversed the direction of the Z axis.

As for powering the board up when plugging in. There is a jumper on the board that will let you choose between when the rambo board powers up, power supply power or USB power. If the jumper is in the power supply only, the board will only power up when the main power supply is turned on. If its on USB power, the board will power up and be recognized by S3D when you plug in the USB cable even when the power supply is off.

pyronaught · Post by **pyronaught** » Wed May 18, 2016 1:44 pm

The connectivity problem went away, then came back again. You know what they say-- problems that magically go away magically come back again. Now nothing can get it working. S3D detects when the M2 is turned on and tries to connect to it, but fails every time. There really seems to be an issue with the USB connector on the RAMBO. When connecting sometimes it displays gibberish for the commands received back from the rambo, other times nothing at all. The connector is not loose, no pins are bent and the solder connections look good so I don't know what the deal is. I have two other M2s nearby that I've been using that same USB cable on and no problems with those two, so it's not the cable. The first time I tried unplugging the USB from the rambo it was damn near impossible to pull it out, so there's definitely an issue with that connector. I'm tempted to desolder the one from the old rambo and swap it out, since I'm already F'ed at this point. Without a functioning USB port I can't update firmware either and the thing is just a brick.

This really sucks because I have a customer who was in such an urgent rush for parts he literally paid the replacement costs on my rambo just to get a 5th machine up and running, including fed ex next-day shipping costs. Now the damn board is bad and he is getting nothing for his money. There's no time to have another board sent out at this point and I'm going to be coming up short four parts a day.

Jules · Post by **Jules** » Wed May 18, 2016 3:12 pm

What kind of computer are you connecting to with the USB cable? Desktop or laptop?

With desktops - it frequently helps with connection issues to have the cable on a printer connected to a rear USB port, not one on the front of the machine. (Don't know why - it just does. I guess they're more stable.)

You might just need to start over with the installation of the M2 - remove it from the system, re-install the driver, don't try to connect it to S3D yet. Then flash the correct firmware for that machine before you try to use S3D with it.

That's what I'd try before ripping the board apart.

pyronaught · Post by **pyronaught** » Wed May 18, 2016 3:36 pm

It can't be the computer, driver, usb port or cable because these are all verified working with two other M2s on the same table. I connect to each of them twice a day to start new print jobs with the same cable plugged into the same USB port and there are no connection issues. It simply has to be the Rambo board.

insta · Post by **insta** » Wed May 18, 2016 4:56 pm

pyronaught wrote:This really sucks because I have a customer who was in such an urgent rush for parts he literally paid the replacement costs on my rambo just to get a 5th machine up and running, including fed ex next-day shipping costs. Now the damn board is bad and he is getting nothing for his money. There's no time to have another board sent out at this point and I'm going to be coming up short four parts a day.

hay srsly I'll help

pyronaught · Post by **pyronaught** » Wed May 18, 2016 6:11 pm

insta wrote:
pyronaught wrote:This really sucks because I have a customer who was in such an urgent rush for parts he literally paid the replacement costs on my rambo just to get a 5th machine up and running, including fed ex next-day shipping costs. Now the damn board is bad and he is getting nothing for his money. There's no time to have another board sent out at this point and I'm going to be coming up short four parts a day.
hay srsly I'll help

Thanks, but I need the money from this gig. I still get paid for doing all the parts even if the final ones are delivered later than originally wanted. I just checked with the customer and they are fine with the extended completion time. I think they are glad to just be getting boxes of usable parts each day, as they were trying to make these themselves and not having much luck I think. When they saw my parts, they wanted to know what printer I'm using and I think they are going to buy an M2 now. They currently have a Ultimaker 2 and a Form Labs resin printer. The Form Labs parts are super smooth and more precise, but I think it takes them about nine hours to make a part it is taking me 4.5 hours to make and it is a lot more expensive. They need 108 parts by early next week, so a single Form printer just wasn't cutting it, and neither was trying to book time on all the 3D printers at a local tech shop.

pyronaught · Post by **pyronaught** » Wed May 18, 2016 7:20 pm

This is what I see on the communication window when trying to connect. The red LED on the rambo board turns on when the connection is trying to be made, then turns off when it fails. The random garbage S3D receives from rambo is different every time, whereas normally that would be readable text:

Attempting connection at \\.\COM15...
RECEIVED: »ÎHaÚ ¤SÜÌiÚü~PúJKä9hP«#;A¢`Âfp2â"/q¦?Ü9/Î8bùï¹Èòq;+ÁÈrGC©÷Ò»Ò#ÆÑâÒ£NºYD,túP`bÄü©Ø9
F2ðÂúDzJqnµ[PJ{&
Testing plaintext communication protocol...
Testing binary communication protocol...
Testing alternate communication protocols...
Attempting RTS reset and trying again...
Connection failed.
Attempting connection at \\.\COM15...
RECEIVED: BAÅÂgMIM1¤y¼@bB"ãW
RECEIVED: Rd®7`F\CZ¦ÜéßaD&
WøMú>d
ZÉ=RïbÇ;¯Ò±ÂÅãÂçN»SUD-\ºP`?#Ì¸@jârsZÄÊAÊí«¬ìÀÅbÄÀÅ`Äæ
|¡M
RECEIVED: æi@Å«wR fîá`
RECEIVED: ©ZzdhîPQ
Testing plaintext communication protocol...
Testing binary communication protocol...
Testing alternate communication protocols...
Attempting RTS reset and trying again...
Connection failed.
Attempting connection at \\.\COM15...
RECEIVED: s\iÌ)ÌhÒü~PúF>ôâ
Testing plaintext communication protocol...
Testing binary communication protocol...
Testing alternate communication protocols...
Attempting RTS reset and trying again...
Connection failed.

jsc · Post by **jsc** » Wed May 18, 2016 8:42 pm

Check your baud rate setting. It should be 115200. If it is, try all the others, starting with 250000.

Bringing Fried M2 Back from Dead

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