SoliForum - 3D Printing Community — OK, what is blocking the PCB holes?

Re: OK, what is blocking the PCB holes?

2013-12-09T19:07:00Z

solder wick demands even more heat so if your already at the limits of the harddware you are using it can make it more challenging

Re: OK, what is blocking the PCB holes?

2013-12-09T18:13:55Z

Solder wick is not my friend. I've never been able to get it to do anything useful for me. I've watched lots of youtube videos, I've tried highly recommended brands of solder wick, it just doesn't function in my hands :-). On the other hand, until I had the problem above with not being able to get the solder to melt all the way (which seems like it would defeat solder wick as well), I've always found a solder sucker to work well (and it even worked on the 3 stubborn holes in the printrboard once I cranked the heat up enough and added extra solder).

Re: OK, what is blocking the PCB holes?

2013-12-09T17:48:19Z

Tomek wrote:

Two things when you face that problem.
(1) Solder wick is your friend. Solder wick is braided copper that soaks up solder like a sponge.
(2) When you only have 1 hole full and a the rest clear, you can just get your heater and quickly heat the header pin and hole so you pierce the hole with the pin without having to remove the solder.

I second the use of Solder wick... saved my butt on many occasions (long ago gave up on a solder sucker.) I've done a ton of TH and SMT solder work, and I really like Mouser Part #: 577-1808-10F. But as with anything, you'll probably get a bunch of recommendations

-Mike

Re: OK, what is blocking the PCB holes?

2013-12-08T04:40:30Z

Two things when you face that problem.

(1) Solder wick is your friend. Solder wick is braided copper that soaks up solder like a sponge.

(2) When you only have 1 hole full and a the rest clear, you can just get your heater and quickly heat the header pin and hole so you pierce the hole with the pin without having to remove the solder.

Re: OK, what is blocking the PCB holes?

2013-12-08T04:08:48Z

Well, I didn't have any of the chipquick stuff, but I did add a blob of my regular solder, and maybe it was lower melting point, or maybe it just retained more heat, in any case I finally got the last hole sucked clean. Thanks everyone for all the good tips!

I was planning to try and figure out where to add wires for additional power to run a QU-BD heater, but I figured I'd add the missing headers while I had the board out. That took so much time that I guess I'll come back to the power connections some other day.

Anyway, I got it hooked back up, and printed something, so I didn't destroy anything. I even tried testing the PWM fan with the manual controls in RH, and it worked properly, so at least one of the added headers is also working fine.

Re: OK, what is blocking the PCB holes?

2013-12-07T22:16:53Z

ronsii wrote:

EDIT: just remembered a technique I use every so often... when trying to desolder small parts that are hard to get at try mixing some lower melt solder in there first as it will make the existing stuff a lot easier to remove.

Essentially what the ChipQuick kits are http://www.chipquik.com ... That concept is how I desolder SMD chips etc when reflowing..

Flux is the other thing - lots of flux to help break that surface tension in the via.....

Re: OK, what is blocking the PCB holes?

2013-12-07T21:45:55Z

just be careful to stay in the center of the hole and start with a smaller bit than the hole or you risk drilling out the via, those holes are probably linked to the VCC grid... don't have a schematic in front of me or I would know

EDIT: just remembered a technique I use every so often... when trying to desolder small parts that are hard to get at try mixing some lower melt solder in there first as it will make the existing stuff a lot easier to remove.

Re: OK, what is blocking the PCB holes?

2013-12-07T21:18:40Z

That appears to be the case. I cranked the heat setting way up and was able to get one more hole sucked out, but the last two are still being really stubborn, so I guess it is time to see if I can find some tiny drill bits. Thanks for the info.

Re: OK, what is blocking the PCB holes?

2013-12-07T20:09:11Z

Probably just holes with more copper contact than the others making the heat from your iron dissipate around the hole instead of in the hole, ground pins are usually denoted by different shape... square

if you don't want to risk more heat then I would suggest getting some micro bits and hand reaming the holes as the solder is usually soft enough to do it in less than a minute per hole.

OK, what is blocking the PCB holes?

2013-12-07T19:54:08Z

I have my printrboard off to modify it for higher current, and while I had it off, I decided to suck the solder out of all the holes for the missing headers and add them. There are three holes that don't appear to actually be holes :-(. I can't suck the solder out of them because the solder doesn't go all the way through:

Anyone have any good ideas about what might be going on here and how I should proceed? As near as I can tell from the board schematic, all three of those blocked holes are supposed to be ground. Perhaps it isn't a coincidence they seem blocked?