My question is how in the hell did you solder the chips on the board? I can do small soldering, but how hard is it really?
Well....
What I used was an aoyue 968 rework station. It's basically a pretty nice soldering iron and an air wand that can put out air at a specific temperature and flow rate. Costs about $160 on Amazon. I bought it a few years ago to fix SMD components on 90's era electric car controllers, think 50kw IGBT drivers that explode and need to be rebuilt.
http://www.amazon.com/Updated-Aoyue-Digital-Soldering-absorber/dp/B006FA481G/ref=sr_1_fkmr1_2?ie=UTF8&qid=1384876991&sr=8-2-fkmr1&keywords=aoyue+962Cripes, you could probably use this:
http://www.amazon.com/REWORK-SOLDERING-IRON-STATION-handles/dp/B004ZB9D4O/ref=sr_1_24?ie=UTF8&qid=1384877176&sr=8-24&keywords=aoyueIn addition I have an Aoyue pre-heater thing which basically puts out a fairly constant amount of heat and holds the board.
http://www.amazon.com/Aoyue-853A-Infrared-Preheating-Station/dp/B000PGPU7W/ref=sr_1_1?ie=UTF8&qid=1384877226&sr=8-1&keywords=aoyue+preheaterFor $20 more you can get a probe. Wow! Modern technology.
To be honest, it's not too hard. You need to put liquid flux on the board (use the no-cleanup flux, try to get some tacky stuff) then put the board on the preheater and bolt it down. Now spend a *LOT* of time with an eye loupe (4x) fingers, and a set of tweezers to put the chip on the board so that:
- The chip dot matches the dot slik-screened on the board. That's um. critical
- The chip is perfectly centered within the silk-screened square. I mean perfect. As in you can just barely see all four outlines around it.
Then you turn on the heat and check the chip again. I brought my pre-heater to 300F because Aoyue assumed I was stupid and didn't use celsius on the preheater. Oh well, check to see if yours is C or F, there is a difference. :-)
Then you get your stopwatch. And time things. After 4 minutes or so fire up your 962. Bring it's temp to flow level 5 and temp of 402C. Yes, that is hot as hell. Yes, it bothers me too. Yes, that's life. 250-300C doesn't do crap.
Check the chip again. It probably moved. If not good. Note the preheat has activated the flux.
Now hit the chip with the heat. I use the round nozzle that is about 80% the diameter of the chip. Whatever. The square one sucks. Put the nozzle over the chip and bring it down over 10 seconds to the point where it is right over the chip. Start the watch.
After 30 seconds I start moving around the edges of the chip with the nozzle. Blow straight down, if the chip blows off you're fucked-ish.
Watch the chip. It should do a little move when the solder melts and it aligns itself. Keep the heat on it.
Do heat for 60-90 seconds. If the board catches fire you did it too long. I felt horrified I needed that much heat but I haven't blown a chip yet. Yet.
Remove the heat, then turn off the bottom preheater. Wait a minute or two for the solder to cool. Then take the board off the preheater, burn your fingers, put on gloves, and walk around with it to cool it down.
Look at the chip. If it's not square within the 4 lines on the board you really blew it. It probably is.
When room temp, plug it into the Jally that you have already flashed with 1.2.9 with the LITTLE_SINGLE definition and made sure it WORKED and see what happens.
If 3 LEDs pop on the back along with the power led, power down immediately. You win.
If not, reheat and try again. Go a bit longer with the heat.
If the front LED flashes, power down, you shorted the 1 volt power supply. Thank BFL for the crowbar detection and come back to this thread. Or re-heat the board again, it might not have soldered correctly.
Anyway if it lit 3 LEDs then put on the heat sink, fire it up and check out the performance. Should be 12gh. Then keep adding chips until something melts.
C