Interesting exercise with Printrboard clone

I recently got 3 Printrboard clones (GEEE Tech) on ebay. Only $60 ea with free shipping from China. (I still don't see how that works.) The boards looked good except they weren't cleaned well - a uniform resin film over them. I figure their cleaning vat solvent was long over due for changing. Not being hugely familiar with Arduino stuff (I had managed to wrestle a Brainwave board into submission once), and with the very confusing verbiage on the geeetech.com wiki page, I had a hell of a time sorting out what type of bootloader was on the thing and whether it was actually working or not. After stumbling around for a few hours, I finally got Marlin built and downloaded.

So I figured I'd go ahead and flash the other two boards. For the life of me, I couldn't get either board to enter bootloader mode like I finally had managed with the first board. At this point, it dawned on me that maybe the reset button was faulty. But on both boards? Then I remembered the flux residue. Sure enough, neither board's buttons were working, and as I though back, I realized that the first board's button wasn't actually working to begin with either. I had to take apart the reset buttons and clean them out with a toothpick. Now everything's working. I guess you get what you pay for...

Does anyone have a suggestion for the least offensive solvent I can use to clean the rest of the boards? Unfortunately, the flux residue is not water soluble.

That's pretty much the experience I've had with Geeetech and SainSmart stuff...

If it's plain old rosin then isopropyl will take care of it. Douse it and scrub with a toothbrush, repeat until most of the flux is off, then let it dry. Acetone works too, but parts like those switches and some connectors may have some ABS and might get dissolved.

If it works i might have to pick one up though. Do you know if they're using the proper sense resistors on the drivers, or zero ohm shunts like the knockoff Pololus?

Thanks for the isopropyl alcohol tip. The rest of the board looks pretty cleanly built, and the current sense resistors do look to be real 0.1 ohm resistors.

Quote
LoboCNC
I recently got 3 Printrboard clones (GEEE Tech) on ebay. Only $60 ea with free shipping from China. (I still don't see how that works.) The boards looked good except they weren't cleaned well - a uniform resin film over them. I figure their cleaning vat solvent was long over due for changing. Not being hugely familiar with Arduino stuff (I had managed to wrestle a Brainwave board into submission once), and with the very confusing verbiage on the geeetech.com wiki page, I had a hell of a time sorting out what type of bootloader was on the thing and whether it was actually working or not. After stumbling around for a few hours, I finally got Marlin built and downloaded.

So I figured I'd go ahead and flash the other two boards. For the life of me, I couldn't get either board to enter bootloader mode like I finally had managed with the first board. At this point, it dawned on me that maybe the reset button was faulty. But on both boards? Then I remembered the flux residue. Sure enough, neither board's buttons were working, and as I though back, I realized that the first board's button wasn't actually working to begin with either. I had to take apart the reset buttons and clean them out with a toothpick. Now everything's working. I guess you get what you pay for...

Does anyone have a suggestion for the least offensive solvent I can use to clean the rest of the boards? Unfortunately, the flux residue is not water soluble.

Edited 3 time(s). Last edit at 01/15/2014 11:52PM by keithlacon.

Most clone stuff from China in the multi-rotor world is coming without bootloaders, you have to burn one on with a usbasp programmer.

I bought one of these after frying my real printrboard while feeling cheap. Can't say it's awesome... For the bootloader I found a site that has an android 0022 that is all setup to upload firmware. You also need to download the teensyduino usb drivers to get your computer to recognize it. These boards are known for a poor ground path from the mosfets and sure enought mine burned out the first time I turned on the heated bed. Easiely fixed by soldering a peice of wire to jump the path. Also I have found the stepper drivers to be quite horrible with the voltage adjustments to be totally out of wack. The price is tempting and it works after a fashion but I would neveer recommend anyone buy these