Midibox 16 help!

Testing/Troubleshooting
1

So.. I just soldered the last wire, and was trembling with anticipation as i plugged in the power supply.. was it gonna blow up?!

Then.. I flicked the switch and… :o

Nothing happened..  :-/ nothing at all. No LED’s came on, no funny LCD messages, no smoke.. nothing.  An anticlimax to say the least!  :'( I’ve spend months building it, and i was gutted when it didnt work (although i knew it wouldn’t.. nothing i build works!)

So i got a couple of questions before i throw the midibox in the bin and order a Evolution UC-33!

1- My power supply only offers 4.5v, 6v, 9v, 12v.. i used 4.5v is that correct?

2- I’ve looked over all the soldering and it seems fine, any suggestions of what might have gone wrong?

If it helps i used the bottom board layout from Heico’s beginners tutorial.

2

hello

i’m not good in electronics , but i should help you

is you mb 16 is based on the Mb64 project with 1 core , 1 din …

or just the MB16 plus ?

if it based on core , have you use the tests program Concepts Menu , this tests program are very usefull for testing your hardware

Tux

3

Hi

Set your power supply to 9V if that does not work try 12V. The 7805 voltage regulator will reduce the voltage to +5V. Your power supply must be able to deliver 500mA, LCD displays and LED’s are very current hungry.

Give that a blast.

Rowan  

4

I pumped up the voltage to 9v and still nothing.

It’s the midibox 16 plus, not the core module thing.

I’ve looked at everything i can do, but with no electronics knowlege theres pretty much nothing i can do.  And the fact that it could be anything makes this even more frustrating!

I suppose the only thing i could do is rebuild the box using one of the PCB’s available, but i suck at electronics so it’ll take me months!!!  Sod it.. looks like evolution will be recieving a nice wad of cash from me! :slight_smile:

5

Right, now that i’ve calmed down  ;D i think i’ve worked out what i’m gonna do.

I think i’m gonna rebuild the box, but instead of using the board i used (not sure what its called - strips of copper with holes drilled in regular intervals), i shall use the PCB’s available and make a core module and build the box with that.  I like the idea of being able to connect and disconnect as it will allow me access to the components just in case i fry something  :)

I’m from the UK and I was wondering who would be best for me to order my PCB’s from?

6

Hi

Good idea. Using a PCB rather than veroboard (board with stips of copper) is a must if you don’t have much experince with electronics, one mistake can cause the whole circuit not to work. I’ll only use a veroboard if the circuit is simple.

When you are building your midibox make sure you take your time. A MIDIbox that does not work is not worth the time you saved. Always tripple check things before you solder, it could save you a lot of heartache in the future.

Best of luck

Rowan

7

have you got the voltage regulator 7805 around the right way? If you have a multimeter, put test leads on pin 1 and 2, you should get 9v. now test pin 2 and 3, you should have 5volts (pin 2 is ground, so connect the black lead test lead there) when you look at the front of the 7805, the pins are 1,2,3 from left to right (leads poking out the bottom!)

good luck, from Steve

8

Well… that’s why I think a debug manual could be a useful :

If you build the whole midibox, and then power on it will probably don’t work!

I make DIY for about 5 years now, and one thing I learn is the murphy’s law!! It won’t work if you don’t understand what you are really doing!

Well, this is the advices I can give you :

first, just build the JDM, burn the firmware in the PIC, see if everything is ok…

Then, build the core (MBHP is easier to build since all module are “independant”), test the voltage on it, put the pic, see what’s appening with midiox…

And then build the DIN and DOUT module…

That’s why I think, even for small midibox, the MBHP can be the best solution.

I know this site for 9 months now, but I only start to build the midibox last week! I made the JDM, it works so I build the core, it works, so I put the pot test program, solder pot, it works… oki! Just do it step after step (is this english???) and you’ll see that it works!

For the 7805 : it output 5V, but it needs more than 8V on input (5V + 3V), but less or equal than 12V (5V+ 7V).

9

Thanks for the suggestions guys.

Yeah i’m gonna bite the bullet and order some mbhp boards.

I’ll have to see what i can salvage from my present box (i guess i can salvage most of it apart from the resistors and caps and stuff.. anything where i cut the leads)

I read a newbie soldering tutorial and i’m a lot more confident with my soldering technique now.. now i’m gonna work on my de-soldering :slight_smile: