Friday, 11 September 2009


Into the cold frying pan, onto the gas hob turned to medium low. I timed it, too. At 2 mins I could see the first two corner parts (motor LED and resistor R7) going melty, but it was nearly all melty by the time I'd taken the photograph:

It is hard to take photographs above a hot frying pan, so once again, apologies for the blurs!
And you really can hear some little "pop"s.

At about 8 minutes everything was melty, to varying degrees, and those first 2 parts were shiny, so I shifted the board around to even out the heat-load better. You can see them at the top of this picture:

The shiny isn't silver as the solder wire goes, but is gold-coloured.

By 10 minutes, the only parts not shiny were the chip and its neighbouring electrolytic capacitor. I moved the board to centre these over the heatsource, and waited some more.

I was concerned that the chip wasn't properly down, so I...

don't try this.....

tried to press it down with my tweezers..... and nudged it out of place.... at just the wrong time....


Ooops. Quickly shoving it back where it should be, I waited another 2 mins, and its solder paste did go shiny. One side is well-aligned and the other? Not so great. It's on the pads, but not perfectly.

And I caused a lot of bridging where the solder isn't separated between the legs. I thought it all looked done, so I turned off the gas, and inspected the board from above.

On cooling, I took some more pictures, showing the poor chip legs (the 5 left-most legs are bridged and two to the right are bridged), and solder balls in various places. You can see one here in front of C6, in front of the rear electrolytic capacitor:

As warned in the assembly instructions, I have the centre electrolytic capacitor (on the left in the picture below) not at all shiny, and needing some post-cooking fine-tipped soldering iron attention.

Once cool (about 10 mins), I went around the board and chipped off the solder balls with the tweezers and.....

.....don't do this either.....

where there were 2 between C1 and C4, I think I managed to crack one of the ceramic capacitors. Oh Blogger!!


Next time, I need to leave individual components well alone whilst cooking, and have a finer implement on hand for removing solder balls. Perhaps my Stanley knife blade, used on the non-blade side, may be better at removing problems
between components if I carefully draw it through the gap.

Oh dear, that wasn't very successful all in all. Will I have to replace the cracked capacitor at C1? It is a 100 nF one, and I don't have any spares.
I have to use the soldering iron to fix the electrolytic capacitor, somehow fix the solder bridges on the chip legs, solder in the resistors that are standing in (literally) for the ones I couldn't find as surface-mount, solder the other through-hole components, and I still have a solder ball between C1 and C4.....


  1. I think I've seen normal solder braid and a normal soldering iron to remove those kind of bridges. I'va alse seen a suggestion that if you re-melt with a soldering iron, the surface tension clears the bridges for you.

    Speaking from internet experience only, at present.

  2. Yep, I'm just reading all the possible ways of dealing with the bridging at the moment. There is a myriad of methods, so I don't think it will be too much of a problem. Unlike the capacitor...!

  3. I am a bit worried about how long you cooked it for. If you look at the recommended profile here it should not be more than 217C for more than 2.5 minutes and never more than 260C. I would strongly recommend testing it before doing the others.