Soldering help

[yotsuya]

Hey, all!

In tweaking my control panel tonight, I hate to say it but the cable ribbon going from my Turbo Twist 2  to the interface board got detached. 

I've learned how to do a ton of stuff in the past six months, but I am sad to say that I just don't have the steady hands needed for such precise soldering. I cleaned off the hot glue blob that was there for support, but I just don't think I'd be able to reattach it without making a big mess.

I know that some of you here are wizards at this kind of thing. I'd be willing to pay anyone here a reasonable amount for their time and skill. I've attached a picture to show how precise it needs to be. Please PM me if you think you can help. Failing that, Randy, do you sell the Turbo Twist 2 master interface board separately?

It's killing me. We're taking my machine to an 80s party this weekend, and I want to be able to play Tempest and Tron the right way! Thanks in advance for any assistance!

[MonMotha]

Oh, that's easy. 

The hardest part is stripping the ribbon cable cleanly.

The first step is to get everything all cleaned up.  Scrape off all the hot glue and such, then remove all the old wire from the holes, if there are holes.  Clean the holes out using a solder sucker and/or solderwick.  If there are just lands on the surface of the PCB, just clean up with solderwick so you have a nice flat surface.

Now you'll need to strip the ribbon cable.  I've had good luck with using a knife to score both sides of the insulation then bending the resulting "stub" and pulling until the insulation comes off, leaving just the wires.  The other option is to use a knife to separate the wires from the ribbon and strip them using wire strippers.  It's usually AWG28 or AWG30, so you'll need a good wire stripper.  The hardest part of the process will be keeping all these wires clean since they are often stranded.  You can try to twist them, but I find it best to just keep things straight and tidy.

Now just place the ribbon's wires into the holes you've cleaned out or cleaned surface lands and solder.

If you don't think you can do it, I can, or ask Randy.  Randy's usually pretty good about fixing things up for people at reasonable cost.

[RandyT]

No problem.  If you send it to me, I will fix it for you.  The only concern I have at the moment is that you won't have it this weekend, unless you are pretty close by.

If you want to go ahead and follow MonMotha's advice, then give it a go.  The only thing I would add is that this arrangement was designed to be easy to solder all of those connections.  You just need to clean the old wire bits off the board, and don't worry about leaving solder on the pads.  Get some electronics flux and dab some on the pads, put a little bit of solder on the tip of your iron and run it across the pads.  It should load up each of the pads with solder, with no blobs joining any of the pads.  Then cut the cable below where the wires separate, so you have a straight across cut and no separated wires.  Using the method MonMotha suggested, strip the insulation away, leaving a little more than 1/32" of exposed wires, and make sure they are all separated, with no wire strands touching adjacent wires.  Put a little flux on each of the exposed wire ends, align to the pads and touch each one with a hot iron.  It should wick the solder right to each wire without too much trouble.  The key is the use of flux.  Without it, it will be much trickier.  As long as you don't leave the iron on the pads too long or try to power it up with a short, and keep the cable in the proper orientation, you shouldn't cause any damage to anything else.

If you have connectors which fit the pins on the board, I can also get you the pinout of the ribbon so you can splice or crimp the connectors to the appropriate wires and just plug them in.

Best to email me on this.

[BurgerKingDiamond]

It really doesn't look like a tough soldering job. The most important thing is to USE FLUX! I ignored this for a long time and my soldering sucked because of it. So flux both the soldering points on the PCB and the wires. Then tin the wires with a little solder. You can also get different sized tips, so try and get one that's really small and pointy for the more delicate stuff. Also, put some hot glue over the wires where they meet the board to act as a stress reliever so that your joints hold.

[RandyT]

It really doesn't look like a tough soldering job. The most important thing is to USE FLUX! I ignored this for a long time and my soldering sucked because of it. So flux both the soldering points on the PCB and the wires. Then tin the wires with a little solder. You can also get different sized tips, so try and get one that's really small and pointy for the more delicate stuff. Also, put some hot glue over the wires where they meet the board to act as a stress reliever so that your joints hold.

If one has a solder pot, then tinning the wires is fine.  If not, it's not necessary in this case.  The key here is to make sure the individual wire strands stay in their own groups, and any extra messing around with them will cause them to splay and work against one in that regard.  A little flux is all that is necessary on the wires.

If yotsuya manages to do a good job, that is permanent, then hot melt is fine.  But I suggest that he send it back so we can do a proper fix, and if he intends to do that, no hot melt.

[yotsuya]

Thanks for all the tips, guys. I'm going to take Randy up on his generous offer to help. All your feedback has been appreciated!

[BurgerKingDiamond]

It really doesn't look like a tough soldering job. The most important thing is to USE FLUX! I ignored this for a long time and my soldering sucked because of it. So flux both the soldering points on the PCB and the wires. Then tin the wires with a little solder. You can also get different sized tips, so try and get one that's really small and pointy for the more delicate stuff. Also, put some hot glue over the wires where they meet the board to act as a stress reliever so that your joints hold.

If one has a solder pot, then tinning the wires is fine.  If not, it's not necessary in this case.  The key here is to make sure the individual wire strands stay in their own groups, and any extra messing around with them will cause them to splay and work against one in that regard.  A little flux is all that is necessary on the wires.

If yotsuya manages to do a good job, that is permanent, then hot melt is fine.  But I suggest that he send it back so we can do a proper fix, and if he intends to do that, no hot melt.

Hot glue can be overkill, but I'd rather make sure it's gonna hold so I don't have to go back later. And it's good for insulation.

[RandyT]

Hot glue can be overkill, but I'd rather make sure it's gonna hold so I don't have to go back later. And it's good for insulation.

There's no problem with hot glue.......so long as I don't have to try to remove it so I can fix what is unerneath .  Some types come off cleanly, and some are more waxy and a nightmare to remove.  Not good to mix hot melt residue with hot solder if you want a good joint.

[yotsuya]

I've sent the part back to Randy already, but for future reference, what would you guys suggest for soldering? I have a cheap iron I picked up on eBay years ago, but I've only used it one or two times, and on nothing as precise as what I would be doing with the Turbo Twist board (or maybe the thought of having to do it five times in a row is what I find intimidating). Do you guys use dedicated workbenches with magnifying glasses and such?

[nick3092]

Depends on how much soldering you are going to be doing, and on what. I've used multiple irons over the years, and the one piece of advice I would give is to get one with a variable temperature control. Pick up multiple tip sizes while your at it. They aren't that expensive, and it's better to have them on hand instead of attempting something with the wrong tip.

Also, if you haven't done a lot of work, find some junk electronics and practice desoldering and soldering the parts. It's a cheap and easy way to get some practice in.

[yotsuya]

Actually, I've never desoldered. What the general process in regards to that?

[RandyT]

I have a cheap iron I picked up on eBay years ago, but I've only used it one or two times, and on nothing as precise as what I would be doing with the Turbo Twist board (or maybe the thought of having to do it five times in a row is what I find intimidating).

The type of tip is one of the more important parts of soldering.  Certain tips are made for certain purposes, and having the right one, provided one knows how to use them, can make all of the difference in the world.  You might be surprised to know that the soldering of fine pitch parts, much smaller than the TT2 board repair, can be done with a tip that is nearly .200" in diameter.  So a grounded unit which can accept multiple tip types, and one which allows for at least some type of heat control, is recommended.  But soldering is a skill, like welding or painting, and it takes some time to become proficient.  If you are good at soldering, you can make just about any iron do what you need it to in a pinch. 

Do you guys use dedicated workbenches with magnifying glasses and such?

We do.  Lots of light, fume extractors and strong magnifiers for checking the work as well.  Be careful if you solder on your dining room table.  The chemicals and metals in many solders and fluxes are not bio friendly, so don't eat while you do it, wash your hands thoroughly afterwards, and clean up well.  Also be sure to provide plenty of ventilation, especially if you have young kids.  If you plan to do a lot of soldering, invest in a smoke extractor.

RandyT

[nick3092]

Actually, I've never desoldered. What the general process in regards to that?

There are 2 ways of doing to really. You can buy copper wick that you lay on top of the joint, and then use the iron to heat the wick. The wick then sucks up the solder. The other way is to use a special tool that sucks up the hot solder in a rubber bulb. Some require you to use your iron to heat the joint, and some have an iron incorporated. Also, watch your heat when desoldering. Too much and you can pull the copper pad right off the PCB. I did that while re-capping my TurboDuo. Luckily I was able to tap in to the other end of the trace. But that might not always be so easy.

And on a side note, props to Randy for fixing the part. That is customer service.

[HaRuMaN]

I'll take a picture of my setup when I get home...  (take a look at my custom title, lol)

I use an el-cheapo Radio Shack grounded soldering iron for everything, and I do a LOT of soldering.

I have a plastic, suction based de-solderer.  The copper braid stuff is practically worthless.

[yotsuya]

What do you do, use the iron to melt the existing solder and then suction it up? How is the braid supposed to work?

[HaRuMaN]

What do you do, use the iron to melt the existing solder and then suction it up? How is the braid supposed to work?

Yes.  The one I use you 'charge' first, then it has a button you press to release the vacuum.

The braid works like a wick, you lay in on the area, and apply heat to the braid...

[yotsuya]

Yeah, it sounds like suction would work better.

That'll be the next thing I learn. Last summer it was using a router. This summer, soldering!

[HaRuMaN]

Buy some junk electronics at a yard sale or thrift store and go to town...

[crashwg]

Yeah, it sounds like suction would work better.

That'll be the next thing I learn. Last summer it was using a router. This summer, soldering!

In my experience, using a suction based desoldering device in combination with a solder wick gives the best results.  The suction takes care of the majority of the solder and the wick gets the rest.  Really both are useful skills in repairing & modifying PCBs.

[jennifer]

          Maybe my sucker sucks [or not], I never could get the hang of that. The wick is awsome though, It gets hot fast so hold it with a good
roach clip and pull it across the melted solder, as it soaks in move to a clean piece.

[RandyT]

+1 for solder wick.

Some solder is really difficult to get out with a non-heated sucker, like through-holes connected to a ground plane.  The ground plane pulls the heat away so quickly, the solder solidifies immediately when the iron is removed.  The solder wick is a perfect solution to this problem.  Always keep some on hand .

[MonMotha]

Agreed.  Good solderwick is amazing stuff.  You can get solder out of almost any place with proper application of heat and solderwick.  Tip: you may have to wet the tip of the iron (with a little solder) or even apply a little solder to the solderwick to get heat to transfer well from the iron to the solderwick before it will pick anything up.  Get decent solderwick, too.  The radioshack stuff isn't very good.  Even the cheap MG Chemicals stuff works decently, though.

I do use both styles of desoldering tools, though.  In addition to my solderwick, I have an old temp controlled desoldering iron (bulb based - the fancy vacuum pump ones are too expensive for my taste at the moment).  The desoldering iron needs a new tip right now, though...

For reference, my main iron is a Weller WESD51.  Should be about $200 new or $100-150 used in good shape.  For another hundred or so, you can pick up a used Metcal station, but the tip cartridges for those can get a bit pricey compared to the Wellers.  Then again, the Metcals are pretty much the Cadillac of soldering irons.

I solder most through-hole parts and QFPs (all the way down to 0.5mm pitch) using the "ETA" tip the came with the iron.  This tip is actually fairly large (1/16" screwdriver), but it works very well for almost any purpose.  I've been meaning to get a "hoof" style tip to better facilitate drag soldering, but it's not required by any means.  For 0603 and some 0805 passives, I use an "ETP" (1/32" conical) style.  For extremely fine point touch up, I have an "ETS" (long reach 1/64" conical); I almost never use it.  1206 passives work well on the ETA tip.  For 0805, a smaller screwdriver style tip can be handy, but is not required (the ETA or ETP works fine).

When in doubt, flux the heck out of things.  Flux makes solder flow and stick.  It also provides some "goop" to keep things from sliding around as easily.  Most fluxes wash away fairly cleanly with isopropyl alcohol.  You can buy the fancy chemical stock stuff, but I just buy it at the drugstore

[yotsuya]

I just watched a YouTube video on solder wick. Interesting stuff!

[boardjunkie]

I've removed hundreds of ICs/sockets from arcade boards with nothing more than a manual spring loaded solder sucker and wick. The key to doing a clean job is using a flux pen on *both* sides of the pcb. The flux "wets" the solder so it can flow easier, and that translates to a more complete clearing of the thru-hole. If you do it right, all you need to do is move each chip pin a little to break any remaining solder bond and the chip should pop right out leaving the board unharmed. Wick is useful for stubborn solder on the component side of the board. With a swipe of the flux pen and wick, pulls it right off. I'll normally clean up both sides of the board after removing the IC with wick and deflux it. Its not really mandatory, but I like to leave the board looking as if no one has "been there"....

[tommyinajar]

Actually, I've never desoldered. What the general process in regards to that?

I just got one.  ( an Aoyue 474A+) Overkill for 1 time job, maybe

[yotsuya]

Just wanted to give a public shoutout/thank you to RandyT for helping me fix my issue. We have such great vendors who offer outstanding support here. I'd buy from him, or Andy, or Bryan any time (in fact, I put in an order for the ClassX with leafs. Ready to try something different!).

Thank you, Randy, and thank you every else who offered suggestions. My wife can now play Tempest again!