Fall of death

[tveiga]

Hello all,
first and foremost I'd like to congratulate Dimitri for this great project and Synthex for the kits.

About 2 weeks ago I bought a kit from Synthex. My soldering skills are very rusty, I haven't grab an iron for 4 or 5 years. Nevertheless I managed to assemble everything, without the LCD and keyboard.
Apart for the USB problem, solved with the pulldown resistor, everything worked well. The solder on the board is horrible but worked.

But then I found that having to use the MCT every time I wanted to change something was not practical and I tried to add an LCD. It worked well, I got the welcome menu then 2 rows of dashes with the first char full, but no light. I realized that I forgot to solder the lcd resistor.

Now, the problems begin. As I was trying to pull the lcd cable the MegaDrum felt to the ground (damn these butter fingers)! I soldered the resistor, connected the MD to the pc and now I don't have the welcome message, only the first row of empty chars and the second row with full chars. The computer detects the MegaDrum but doesn't receive midi signals, and when I run the MCT I get a firmware update message.

Since the soldering is not well done probably the problem is that I have a bad connection that got broken on the fall. But I can find it!
Probably the problem will be in the connections of the atmega right? How to I debug? Is it possible? Is it better to remove the components and try to solder again (now my skills are way better)?

Thanks in advance.
Tiago Veiga.

[dmitri]

I knew you would drop it so I wrote this some time ago:
http://www.megadrum.info/forums/viewtopic.php?f=3&t=492

[tveiga]

Hi Dimitri,
thanks for the fast reply. I saw that topic but I don't think that this is a LCD problem. The LCD didn't fell off, only the board.
And now I don't have any midi activity, with or without the LCD connected.

Are you saying that is a broken atmega or broken crystal?

[dmitri]

Hi Dimitri,
thanks for the fast reply. I saw that topic but I don't think that this is a LCD problem. The LCD didn't fell off, only the board.
And now I don't have any midi activity, with or without the LCD connected.

Are you saying that is a broken atmega or broken crystal?

That topic is not about LCD having problem. It's about a range of possible problems which manifest themselves with an LCD not working properly.

[tveiga]

In short my problem should be one of these:

• Atmega is faulty. Replace Atmega.
• A faulty Atmega crystal. Replace the crystal.
• Incorrect capacitors connected to the crystal. Replace capacitors.

right?

[dmitri]

In short my problem should be one of these:

• Atmega is faulty. Replace Atmega.
• A faulty Atmega crystal. Replace the crystal.
• Incorrect capacitors connected to the crystal. Replace capacitors.

right?

It can also be:
Broken tracks.
Loose connections.
Shorts.

[tveiga]

Ok, thanks for the orientation. I'll look into it.