First MR-16 completed! ...but question on potential damage

[Heinekenator]

Hello.

I completed my first MR-16 today, with 2 more from the co-op waiting to be assembled. This was my first time soldering, and it was actually enjoyable! A bit frustrating at times (I installed the jumper blocks upside-down), and had to re-do a bunch of joints, but all in all a great learning experience.

In my assembly, I ended up with a couple of careless errors. First, I didn't install one of the .1uf capacitors, the right-most one directly above the 8-pin chip. Second, I put the 1k resistor in the 180 resistor's spot. And third, I have nothing in the 1k resistor spot. I'll go back and fix everything before powering it up again, of course.

I had the device powered up for about 15 minutes, and channels 1-3 functioned perfectly, testing with both Vixen and the Lynx DMX Deck . No DMX activity light though. The 7805 got fairly warm, but never too hot to touch. Is it likely that I caused irreparable damage to any of the components by running it in its current form?

One other quick question, regarding solder. I'm using a small adjustable 50-watt soldering station (You are not allowed to view links. Register or Login). There's no temp gauge on it, though, only an adjustment knob that's marked in 20% increments. I'm using the Kester lead-based solder that has been recommended in numerous other threads. I did most of my soldering with the knob around 60-80% mark, and turned it up a bit for some of the bigger parts (spade lugs, mosfets, etc.). Is this too hot?

Thank you very much in advance. And thanks for the wonderful community.

-Greg

[combustionmark]

The 7805 will get warm, as long as the magic smoke didn't come out of anything, you should be OK.

Not sure why the dmx led didn't light, maybe the 180 resistor. I wouldn't worry about it much if everything else is good.

Good job. The next 2 will be easy now. Just take your time.

Have fun

[rm357]

My 45 watt iron has a continuous dial.

I run it at 65 for small parts and about 85 for larger stuff. The trick with a hot iron is to get done and off the part faster.

I usually count to 6 for everything but the really big stuff.
Start counting when the tip touches the joint
Slowly add solder on 3, 4, & 5
Keep the iron on the joint for another second
When I pull away, I expect the solder to be wicked back to the joint - no sharp points stand off the side of the joint, if they do, I reheat the joint for a few more seconds.

If there is a heavy trace, it can take a little longer before the solder will melt - I try to touch the solder to the joint, not the tip of the iron. If you can touch the solder right at the hole, some of the flux will go through and it will flow better through the hole (via).

RM

[tbone321]

6 secondes seems like a long time, especially for small components.  It seems like your iron may not be hot enough. 

[rm357]

I'm not doing the 1 thousand or 1 Mississippi thing. It's really only about 4 seconds per joint on the small stuff and chip sockets.

I almost always have nice shiny well formed and symmetrical joints. My bad habit is putting too much solder and getting little balls on the front side of the board. At least I know it's a good joint and it won't hurt anything as long as it doesn't short between two traces.

RM