- On my very first startup trying to power on, I got nothing at all. I did the logical thing and reheated a bunch of connections - especially the two push button connection on the encoders.
- After putting everything back together I tried again and sure enough the "flash drive" showed up on my computer.
- I got the latest firmware, unzipped it and then put it into the flash drive. That's when trouble started. I guess everything takes off once it has firmware.
- I noticed a tiny whiff of smoke coving from the 2x3 pin board (3.3 v?)
- I immediately cut the power. Well actually just unplugged it. I was running a reduced voltage, like 8.5.
- I checked everything. Both power supply boards seemed warm. I checked it all over again and plugged the power back in.
- I pushed the power encoder and a transistor on the 2x4 pin board lit up - literally and burnt. It was near the far end of the board by the big cap.
- I remeoved the power and started trying to diagnose it.
- I don't think I checked resistance on the power rails to ground prior to this.
- On the VCC rail I get an open. On the VDD rail with the burnt power board installed there is a dead short on VDD.
(I am measuring resistance between the VCC or VDD rail and ground - open is infinity and dead short is 0)
- If I unplug the 2x3 pin board there is no change in resistance - it is open with and open without the board installed.
- If I unplug the 2x4 pin board there is an open and when I plug the board back in - it's a dead short.
- I have an unfiished QMX (not +) and if I plug in its 2x4 pin board, it is open NOT shorted.
- Oh, BTW, there is no short to ground on the V+ either.
I have a ticket with Hans, he suggested I poll the group to see what you guys think.
I'm not sure where to go from here. I'm hoping the main board is OK.
But I don't want to incinerate another power board if I can help it.
I was super careful building the kit. I used the recommended precautions/procedures soldering on the main board (6 layers). I have searched the board with a jewler's loupe and have not seen anything odd... I have been building electronic kits starting with an RCA Voltohmyist VTVM when I was young - 5th grade maybe?
I sure hate to think I toasted the thing...
--
Dan Reynolds -- KB9JLO
<><
Dan Reynolds