PicKIT-3 has cold-soldered USB - Can I repair without SMD tools? - Page 1
Forum section: electronics / repair

author: Cliff Matthews
author_rank: Unknown
timestamp: March 20, 2015, 06:25:15 pm
content: I have a PicKIT-3 that broke its USB off with only minimal use. I know Dave J. put this one over the grill, but it's all I have...I called Microchip and they said it wasn't covered. So I bought a new soldering iron with a sharp tip to do the job, but I'll get just one try to fix it - too much heat and it goes to the dumper. I have two questions:Can I de-solder and re-solder that 12mhz crystal without wrecking it?Do I need any other stuff (like solder paste or fancy resins, etc..)

author: Christopher
author_rank: Frequent Contributor
timestamp: March 20, 2015, 06:30:37 pm
content: If you take Y1 off you should be able to get good access into the pins.Flux, remove solder with braid, clean and inspectFlux, seat component, tin corner pins, inspect usb pins, flux, solder pins by tinning tiny tip then dragging each out in series, add more flux. Inspect with jewlers loupe and clean.Refit Y1Should be a 10 min job

author: Andy Watson
author_rank: Super Contributor
timestamp: March 20, 2015, 06:32:52 pm
content: Quote from: Cliff Matthews on March 20, 2015, 06:25:15 pmLooks like it's about fall off anyhow! Yes - gently lever one end a little, then the other. Repeat until the part is free.QuoteI would clean up the pads with solder wick, then resolder the parts - possibly with a small dab of flux.

author: Cliff Matthews
author_rank: Unknown
timestamp: March 20, 2015, 06:51:50 pm
content: I don't have any solder wick and I've never used it with any success (mind you that was 30 years ago, maybe the technology is better now). This thing is tiny... Couldn't I just lift the crystal, clean the areas with IPA, add a little pen-flux (I've never used that either) and then solder?Also, the only solder I have is old style tin/lead - Do I need that new solder too?

author: Andy Watson
author_rank: Super Contributor
timestamp: March 20, 2015, 07:04:18 pm
content: Quote from: Cliff Matthews on March 20, 2015, 06:51:50 pmDo that. The advantage of cleaning the pads is that it allows the component to "sit down" on the board before you re-solder. The crystal shouldn't be a problem because you can work both ends individually.

author: Christopher
author_rank: Frequent Contributor
timestamp: March 20, 2015, 07:18:25 pm
content: Tin/lead solder is the best kind. I use the following bits for every SMD joint:-http://uk.farnell.com/multicore-loctite/mm01019/solder-wire-60-40-sn-pb-190-deg/dp/2293234http://uk.farnell.com/chemtronics/es835be/cleaner-flux-off-200ml/dp/860414http://uk.farnell.com/electrolube/smf12p/flux-pen-12ml/dp/891186http://uk.farnell.com/multicore-loctite/nc-bb/braid-desoldering-1-5m-2-59mm/dp/252505Doing this without braid or the best consumables will make your life a nightmare. Would recommend doing a bit of practice first..

author: Cliff Matthews
author_rank: Unknown
timestamp: March 20, 2015, 07:27:05 pm
content: Thanks Andy, I'm a little nervous but I'll give it a go!Christopher, if I buy all that stuff it would be nice to have, but then I could just buy another picKIT (or better still, a nice clone). I'm an almost retired, through-hole guy still trying to get up to speed - let's see where this goes with IPA and a flux pen.Once this gets working, the old USB cable will get an extension and some hot-snot will get put around the end so this never happens again... Dave was right, PicKIT-3's are pure junk!

author: Christopher
author_rank: Frequent Contributor
timestamp: March 20, 2015, 09:03:58 pm
content: Get the solder braid, should be a few bucks at your local store for a reel to clean up the pins. Will be a dogs dinner otherwise.I agree! We had two at work, the pin header socket connecting to the PIC's contacts splayed out after only a few 10s of uses.. Cost me a week of headscratching thinking my design had messed up due to programming errors!!! Replaced them with some meatier ones and lesson learned: use connector savers, (gender benders) on all connectors! Actually, lesson learned was use arm