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I recently built an Alpha Clock Five. It was working fine. I brought it to work today, to show it to some of the other geeks. When I got home, I went to plug it in, and it didn’t work. There was a small flash (arc?) from the a/c outlet as I plugged in the power supply, but the power supply is working. I measured its output at 9.2V at the jack. I also checked the Reg 5V point on the PCB, and it shows 4.92V, so it’s got power, and the regulator is working.
What should I check next?Thanks for the help,DavidYup, that sounds like a problem, and not one that we’ve seen before.
So, there are two basic possibilities. Either the microcontroller is running, or it isn’t.If it is not running, that could be due to not being seated properly in its socket, or a bad solder connection at one of several critical points such as the crystal oscillator. Gently take off the LED digits and look at the bottom of the circuit board to see if you can see any signs of what might have gone wrong.If it is running, then it is possible that through static discharge (or something similar) the LED driver chips were damaged, and are no longer producing lit LED segments.Now, how to tell the difference? The alarm and rear-panel “nightlight” LED are independent of the LED segments, and should respond normally if the microcontroller is actually running– although it may be hard to navigate to the right menu places to test those. If you have a USB-TTL interface, you could also try reprogramming the clock (or simply communicating with it via serial) to see if it’s up and running. (You could also try reflashing the bootloader, if you happen to have an AVR ISP programmer handy.)If all else fails, you might consider sending it back to us for analysis and/or repair– again, this is not something that we’ve come across before (unless it does turn out to be a bad connection, as it usually does).The arc itself probably isn’t harmful– the power supply seems to have survived –but it’s possible that there was an electrostatic discharge at the same time, or that the power supply let through a voltage spike. The crystal or the memory of the chip could have possibly been damaged, although (and if so) that’s not really something that we’ve seen before in this kind of context.
The best option might be to try swapping in a good chip, to see if that helps. If the MCU is not running at all, then it probably can’t be programmed through the FTDI cable.Hi David,
Please contact us directly at the store by e-mail to arrange for a replacement chip or return shipping.-WindellHrrm, So mine has also died (I’m the one that made the bike turn signal variant) I had shelved it in a working condition ~ 4 months ago and wanted to get it remounted this weekend.
Plugged it in, LEDs lit up some. Unplugged it, reconnected a wire I had solder to the Time/Settings button, went to reprogram it and got ‘programmer is not responding’ and now I don’t even see any LEDs light up.I’ve got no problem buying replacement parts I’m just not sure where to start to make sure I’m getting the right thing? Should I just assume I some how fried the atmega?I am not sure exactly what the problem is, but it doesn’t sound like a chip kind of problem. If some LEDs were lighting up initially, it’s almost certain that it is not– it’s much more likely a power supply type of problem or an already weak connection somewhere that was coming loose. Do you have an alternate power supply that you can test? And, you might want to open up the case and look carefully through the PCB to find any possible loose or cracked solder connections that might be at fault. If you really get stuck, you might also consider sending it to us for diagnosis; we’re pretty quick at finding problems like these. :)
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