Soldering problem with FTDI on Sanguinololu boards

Hi. I'm building a couple of Sanguinololu boards and am stuck, with both, at the FTDI chip stage.

After soldering the chip + associated capacitors then plugging each into my Mac via USB:
- board #1 doesn't do anything (i.e. doesn't appear in the System Profiler or in /dev )
- board #2 results in an error stating that the USB device is drawing too much current so has been disabled

I've checked and "touched up" each several times, looking for and eliminating bridges, and made sure all the leads are attached. Everything looks OK-ish, but I need to figure out which leads might be over or under soldered.

Anyone have suggestions on which pins to check or any ideas on what could be wrong with either of them?

Thanks!

Edited 1 time(s). Last edit at 06/02/2011 06:33PM by conanh.

For anyone having similar issues...

Flux is essential. After alternating brushing some on then touching each lead/pad a couple of times, I got board #1 working just fine.

#2 isn't working still, but it looks like I've got way too much solder on it, so there's likely a bridge somewhere I still haven't gotten rid of...

I have to reiterate first reply. Flux is your friend. Watch some YouTube videos on surface-mounting components... It'll change how you work on your soldering projects!

A good tip is to take a toothbrush and alcohol and scrub the back of your board. Take your magnifying glass and look at the connections – if it's not working, most likely its bad soldering.

Glad you sorted it out, conanh!

Use a chisel tip, a lot of flux, the smallest solder you can get (< 0.5mm) and a solder wick to remove exessive solder.