I'm preparing to fix my TV. I've borrowed all the soldering equipment I imagine I could ever need, including a nice, temperature-regulated Weller WES50 soldering station with a pencil-tipped iron. I've got desoldering braid and a solder sucker. I've got rosin-core solder. I've got the ICs to replace in my TV. I'm ready.

Before I destroy my TV, I figured I should practice, since I've never done anything like this before. I'm having trouble and thought I'd ask for advice. I'm having absolutely terrible luck making good solder joints. The various FAQs I've read said it only takes 2-3 seconds for the iron to heat up the wire and PCB, and that's about right for when I've practiced desoldering, but it's taking much longer to solder, and I'm often getting the solder ballng up rather than flowing smoothly.

Based on the FAQs, I think my problem is that I'm not properly tinning the iron. How exactly is this supposed to be done? I've tried a variety of different temperatures, but anything hot enough to melt the solder seems to evaporate it and leave behind a dark, wet-looking coating on the iron, versus the silver coating that I want. Do I need to clean the iron first? Any advice?

I think you need to clean the tip on the iron. Try heating it up then wiping it with a damp cloth or a sponge.

I'm not a pro, but what I find works for me is to use the thinest solder I can find. I heat up the iron, wipe it on a dry cloth (rag), apply a small amount of solder to the tip and use the now melted solder to heat up the wire / pin that I'm working on, rather than the dry tip of the iron.
add a touch more solder, then leave the iron tip on the pin until the solder flows.
now I don't know this bit for sure, but I think if the solder balls up it means that the parts I'm working on didn't get hot enough. melted solder on its own wont do the trick, every thing needs to get hot enough.
the solder I use is real thin, like 0.020 inch or so. maybe less.

again, I'm not a pro. and my work doesn't look as good as most of the stuff I see.

hth

Additional flux of the appropriate variety (rosin, never acid) can help, assuming everything is getting up to heat and the solder is still not flowing properly.

More flux!

Get a "flux pen".

Temperature of the soldering iron should be about 150 degrees Celcius above the melting temperature of the solder, so with a regular 60/40 solder 350 degrees celsius is good. As was said earlier, clean the tip on a dry or moist rag, apply a little solder to the tip to make a heat bridge and heat both the pad and the wire/pin. Then apply some more solder on the pad and wire/pin on the opposite side of the soldering iron. Remove the solder and remove the iron. This normally takes only a few seconds. Heat it too much/long and the pad will loosen... If the solder balls up, let the solder cool down properly, add some flux and reheat for a few seconds.

Stig

I just finished the soldering and am about to reassemble my TV. Turns out, the problem was that the tip on the iron was shot. I bought a new $5 tip, and it now works exactly as it's supposed to. I replaced the two amplifier ICs (X and Y for each of the R, G, and B guns -- about 40 solder points in all) plus three resistors that were clearly charred to a crisp. Those resistors were burned sufficiently that the only way we know what to replace them with was to look at the Hitachi service manual, which I was thankfully able to find online. I love the Internet, I really do.

It's amazing how, once I had it all figured out, that I could blast through all those solder points in zero time flat. Now, fingers crossed as I head back to the TV...

Knew you could do it.

Nothing beats the satisfaction of repairing something yourself. I remember when I finally solved the grid problem on my RPTV, it was just an awesome feeling.

Yup, it took me 20 minutes to get things properly converged using the service menu (and more instructions found on the net), but now it's running absolutely perfectly. If anything, it's better than beforehand. The dead resistors were rated for 1 watt, and I replaced them with 2 watt resistors. Hopefully, I'll get the extra year that I want out of this set.

Next up, now that I know my way around solder: finally fixing the flakey pins on my empeg sled.

Edit: ran it all night, during our karaoke New Year's Eve madness, and it seemed to work fine. I'm seeing some drift in the convergence, but it's within the defocused fuzz of the CRT guns. I figure it needs some serious burn-in before I want to get in and do micro-tweaking of the convergence. When I want real sharpness, I'll eventually break down and get a fancy flat panel...

Agreed. That's surface-mount technology, really microscopic stuff.

That is pretty big for surface mount actually...

Yeah, but that's like saying "A humvee is pretty small, for a military truck modified for civilian sale."

No. I mean it is big enough for somebody who is reasonable with throughhole components to attempt if they've got a good sharp tip on their soldering iron and lots of flux. Small would be the SMD resistors in the Mac mini. Click on the "But before you rush into it, take a look at the size of the resistors." link to see what I mean.

If you're unsure then don't try it as you'll more than likely break it.

How big, exactly, is the 0.1uF capacitor? Is it anything like this?


If so, then I'd best leave it to a pro...

I did mine with a throughhole capacitor and it works just fine.

You could get some smt experience buying a kit from Ramsey .

This seems like an appropriate thread to mention a video I just found, which shows techniques for soldering/desoldering various SMT components, including largish chips.

It's quite good:

Surface Mount Soldering 101.

-ml

With all the 'open minded' videos out there I was getting worried when it started talking about soddering...

But after a few seconds I was giggling irrationally at the soddering this and soddering that....


Great video though - thanks...

That's how it's pronounced in the US (and probably Canada, too).

Yah- 'sodder'...

Like that fish- 'sammon'

I thought the pronounciation was unusual too. But with hindsight, I can't think of anywhere I'd likely have heard 'solder' pronounced by an American (or a Canadian) before - it doesn't normally crop up in everyday situations that I encounter, nor hear on TV. Well, at least *that* many times to become noticeable.

Perhaps this is the right place to ask how (or for other examples of where something like) "Quahog" in Family Guy is pronounced "koh-hawg" - to me it should be "kwa-hawg". The "kwa" (Qu) I presumed would sound like just like it does when we all say "quick" or "quack. That one really threw me for a while and I presumed it was a part of the comedy I "didn't get" - perhaps it still is?!

I don't watch Family Guy very often and I've never heard of a Quahog before, but wikipedia says the name stems from a Native American word.
http://en.wikipedia.org/wiki/Quahog

So, all pronunciation bets are off!

Ah, thanks for the clarification - that's one less mystery for me to contend with!

And then there are geoduck clams, pronounced gooey-duck. No, I didn't misspell it. Go figure.

I can't say that I've ever heard it pronounced any other way. How's it pronounced on the other side of the pond?

By pronouncing the 'L'.

I saw a Discovery Channel documentary on those a couple of months ago. Never heard of 'em before that. Can't imagine somebody would want to eat that though. These things looked pretty disgusting to me. Then again, people eat more disgusting things than just this...

While we're at it, that same site has lots of other useful information,
including a more basic How to Solder Correctly (and Why) video.

Cheers

-ml