Another bizarre problem!

[ohawker]

Ok another update, Device Manager says "This device cannot start. (Code 10)" when I use just the USB PIC, and shows no MIDI ports. I am so confused, I don't see why it would communicate enough with the PIC to identify it, but then return an error!

With Atmega, still 'Unknown Device' with no driver installed. Updating drivers does not work

[Synthex]

Do you check 12MHz and 20MHz crystal connection ?

[ohawker]

Yep, crystals are fine (well, no shorts at least). Laptop is now trying to install an 'Unidentified Device'.

I am re-installing my laptop USB hardware in case it is that, is it worth simply buying new IC's? I'd rather not if I don't have to, but I'm sure the finished product will be worth it

[Synthex]

Check for short-circuit and ground.
The pcb must be on an insulating and not conductive surface to make the tests.

Are you in an environment with many parasite ?
Could you make photos of your PCB ?

[ohawker]

Sorry, what do you mean by parasite?

I will do a big short-check in a minute, and working on a wood surface:) Photos, I'm afraid my camera isn't good enough to show any particular detail! Not that you'd see much, my USB connections went wrong (USB pads on the PCB came off from having wires soldered directly to them) so I've had to solder my connections onto different contacts on the underside of the board and tape the cable to the edge of the PCB (very crude but it does the job )

Any other suggestions? If not I will just get a new USB IC and hope for the best

Thanks for everyones help so far!

[dmitri]

Sorry, what do you mean by parasite?

I will do a big short-check in a minute, and working on a wood surface:) Photos, I'm afraid my camera isn't good enough to show any particular detail! Not that you'd see much, my USB connections went wrong (USB pads on the PCB came off from having wires soldered directly to them) so I've had to solder my connections onto different contacts on the underside of the board and tape the cable to the edge of the PCB (very crude but it does the job )

Any other suggestions? If not I will just get a new USB IC and hope for the best

After reading what you did with USB connection I doubt very much that the ICs are to blame Find someone with a camera and take close up pictures of the PCB, especially around where you did USB soldering.

[ohawker]

I thought my last post would raise some eyebrows I will try and get my hands on a camera. In the meantime I will remove and check/resolder all those joints although I don't understand how a dodgy USB connection would affect that, surely it would either work, or not work? Not 'recognise but not function provided the Atmega isn't connected'?

Will post new pics ASAP!

[ohawker]

And here they are came out much better than I expected, only digital camera of any quality I could find was on my phone!

Believe it or not, its not as bad as it seems... ok its pretty bad, but there are no shorts, and it seems to work fine without the Atmega! It seems to be working ok without the Atmega now, MIDIOX recognises the MIDI Ports.

And now, bad to worse, worse to even worse, it has now stopped powering up properly. I plug it in, power starts at 2V and rapidly falls to below 1V, and slowly decreases from there. I am convinced there is some small fault somewhere causing all the trouble! Seems like a capacitor discharging or something, I don't know. I just don't understand why all these faults are developing so quickly. It started out fine, with no problems at all, even rigged it up to a mock pad and used it for snare practice am I right in thinking that they would be linked?

Cheers

[ohawker]

Ok, here I am more confused, althouh I'm sure this will be helpful: removing the second multiplexer (second from top) seems to fix the voltage drop problem, and laptop is actually recognising MegaDrum! True, it says 'Unidentified Device', but thats better than nothing

[Synthex]

I think there was some short-circuit ... can you remove all the residue lean ?
Can you make a photo of the entire PCB ?