Burnt Project Board / Need help

I recently attempted a go at the "Start Here" and ran into some problems pretty fast, 

as beginners, my freind and I burnt the 4 holes on the board that control the 2 motors, and when i say burnt i mean that the pins dont even solder properly anymore, ontop of that even if u can get it soldered too the board by using alot of solder, the pins just don't work, they have no connection. We know this because we continued on to the build and got to the programming, and the servo works, the distance sensor works, just the wheels dont work.

Any solutions? and buying a new board is our last option

i was thinking maybe we can try rewiring the board so that we can get a connection from our motors to the place they need to go, or maybe moving the chip onto a breadboard and trying to recreate our board frmo scratch, but i can't find any information to either of these solutions.

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Calculon320's picture

You can easily just build the h-bridge circuit, described in the user's manual, and connect pins 4-7 to it. Calculon has had this exact problem, and that's been his solution.  Do like this:

...except this way you can use any outpins on the project board. You can even save on parts by using the diginal in/out pins (portc) for this. If you look up the original Yellow Drum Machine, Fritz has used this method for the ancillary h-bridge that controls ydm's head.

Or, even better, you can take a 16-pin socket and bend the pins that correspond to the OUT pins in the picture above. Solder the motor wires to those pins, and it becomes an L293d adapter socket. Then you plug it into the project board exactly like it was and just bypass the burnt out pins. Calculon has also done this on several occasions and it works like a charm. (you'll want a dab of hot glue or polymorph on the side of the socket to hold it into the other socket. Then continue the Start Here exactly like you were

That looks really complicated especially cuz this is my first robot, ill try to watch some tutorials and stuff, but now i know that the board can be re-routed to bypass that that's all i really wanted to know, i was wondering tho, should i just take my microcontroller out from my board and use a pcb to try and make my own board, because ive seen alot of videos where people have done that

Calculon320's picture

You can definitely do that. But it would be as complicated as anything else described here.

is there a picture of this h-bridge zoomed in, to see exactly where the connections need to be made and whatnot

The soldering iron i use has been changed to a more suitable one

Ill try to get to get the picture, but that might take some time, the board is the exact same as the one from the Start Here, the Picaxe 28 board, if they helps, so i think the wire is the best idea, but where do the ends of the wire go? Picaxe 28 board, from the start here

lumi's picture

Having problems with my internet and setting up Windows 8 ion my machine now...so not much time to search by myself. Please ask Fritsl for the schematics or help that he can point you to thr right spot on the board.

 

Is it hard trying to re-create the board on a breadboard?

lumi's picture

Just do the following. Trace the source of the trace pitch and solder a wire direct on this source. Pull the wire to the target hole where the pads has been, put it through the hole and solder the motor wire onto it. Basically replace the trace with a wire. See below

Make sure you are using a small enough soldering iron, maybe 25 watts that you not burn more of your board.

rhmbraun's picture
What kind of soldering iron do you have? It may be that your iron is too hot for the solder. Solder requires a range of temperature to get a good joint. You could move back from the pin along the trace and solder the wire there.