deleted firmware, and megadrum cannot connect to pc

[atomburst]

yay almost there. I re-checked the board, and found something suspicious, it was a 4-pin connector that may have not been getting a good connection, i have fixed that up, and i also replaced the 16mhz crystal with a 20mhz crystal. both of these crystals were provided to me by synthex when i bought the kit. now when i plug my megadrum into the computer, it is recognised and windows 7 says it is ready to use, and then it is quickly disconnected. it continues to connect and quickly disconnect itself and does not stop until i turn the megadrum off.

i looked around and came across these two threads:
http://www.megadrum.info/forums/viewtopic.php?f=6&t=41&start=70
http://www.megadrum.info/forums/viewtopic.php?f=3&t=244

in one of these, synthex has stated that a 20mhz version. I assume this used to be the case but is not so anymore, as when i start my megadrum up, there is the option of a 20mhz update option. In any case, would this new crystal be the cause of my new problems, or is there still something else i should check?

[dmitri]

Until I see the evidence that

5. PIC18F2550 is mulfunctioning. Check that your PIC is loaded with correct firmware and the schematic matches the up-to-date schematic: viewtopic.php?f=3&t=266.

is checked and corrected, if needed, I won't be able to help.

[atomburst]

well the only change i have made is to pull that pin over to ground via a resistor. ive forgotten the pin number and value of the resistor because i did it a while ago. is that the only change that needs to be done? i assumed it was because that is all i got told to change...

[dmitri]

well the only change i have made is to pull that pin over to ground via a resistor. ive forgotten the pin number and value of the resistor because i did it a while ago. is that the only change that needs to be done? i assumed it was because that is all i got told to change...

Is it all what it says in

5. PIC18F2550 is mulfunctioning. Check that your PIC is loaded with correct firmware and the schematic matches the up-to-date schematic: viewtopic.php?f=3&t=266.

???

[atomburst]

i have finally found time to take some pictures of my board to help you.

http://s276.photobucket.com/home/atomburst

some were taken just to show what is going on, or what i have done. these include the photo of the lcd screen, just to show that my megadrum powers up fine and the lcd works properly. the other is the one that is out of focus, is just to show that i have the 47k resistor soldered to the board and to ground.

as i have said previously i have changed the crystal with a brand new one, but it still has not fixed this issue that my megadrum keeps connecting and disconnecting.

any help would be much appreciated.

regards, isaac

[kupooglop]

even though pc board pics are blurry, it looks like it could use a REALLY good cleaning. i'd get rid of all that flux-like residue. a bunch of solder joints look questionable as well. why did you bend pins like that? some look like they are awfully close to each other. the problem you describe sounds like a short in pic circuit between pins that are too close together and dirty with flux or a poor connection that causes pic to cut on & off because solder not connecting the components to the board well. atmega & display part look like it might be o.k...?

[dmitri]

5. PIC18F2550 is mulfunctioning. Check that your PIC is loaded with correct firmware and the schematic matches the up-to-date schematic: viewtopic.php?f=3&t=266.

Please, tell me, besides checking the schematics what does this tell to check?

[atomburst]

apart from the time that i took the pictures, the megadrum was programmed with what i assume to be the latest non-protected firmware version and the device still continued to connect and disconnect. i have since loaded firmware version:
20091217
and it continues to disconnect and reconnect, and now i am still having that weird lcd problem. this time it is not black boxes that pop up, but when cycling through the menu, some letters stay where they are and other characters and letters are refreshed so that everything ends up as one big jumble of letters on my screen.

what is going on?

[dmitri]

what is going on?

You ignore what I suggest you to check.

[eloma33]

Hi,

I install the last encripted firmware ATMEGA644-56-20Mhz on a synthex 2.5 version.

When I connect the PCB to usb, afeter a while, it connect, disconnect, connect, disconnect... and I don't know why...

Somebody has the same problem ?

Thanks