Soldering/Desoldering and headaches...?

[DrGonz78]

I have a quick question to anyone who has ever worked on GK Backline type PCB boards. I am trouble shooting a board right now and do not like it at all. It is made of great material and is very well built, but when it comes rebuilding...? This amp is so hard to work on that I think it would make a great door stop. Almost want to give up but it is in my blood to keep on trying. My thought here is ask others if they have had the same problems working on these PCB's and what I should do differently than most boards. It is like one step away from working on a Line 6 or Behringer amp. Thanks for reading my gripe, thanks.

Edit>>> My main gripe is trying to solder off something from the board. The bridge rectifier was a pain in the butt, but it was easy compared w/ the transistor I tried to remove tonight. That makes no sense that it is soldered on top and bottom of the damn board. Well, does anyone have a good idea how to work on this board?

[52 Bill]

I have a quick question...My main gripe is trying to solder off something from the board. The bridge rectifier was a pain in the butt, but it was easy compared w/ the transistor I tried to remove tonight. That makes no sense that it is soldered on top and bottom of the damn board. Well, does anyone have a good idea how to work on this board?

This is not a question that can be answered quickly. What sort of iron do you have? What sort of desoldering system do you use, vacuum, wick, chipquik?

If you are removing parts that you know are bad, cut the legs off close to the board. This will allow the lead to get hot enough to be removed easily. If you are pulling parts to test and reuse, then you will need to use some sort solder removal system or you will cause damage to the board.

[g1]

That makes no sense that it is soldered on top and bottom of the damn board. Well, does anyone have a good idea how to work on this board?

Sounds like you are describing double-sided board, there are traces on both sides and they are connected by feed-throughs (which are like little tiny pipes). These boards are easily damaged by excess heat, and it is easy to tear out the feed-throughs when removing components.
There is a fine line between enough heat to remove the component and enough heat to damage the board.
52Bill's suggestion of cutting off the legs is a good option if proper tools such as a desoldering station are not available.

[jrfrond]

If you are going to work on double-sided or multi-layer PCB's, in lieu of a good desoldering station, you need a low-melt solder and RMA paste flux like Chip-Quik AT THE VERY LEAST. Sometimes you need both. If you can't handle it, bring it to someone who can. Those PCB's have a nasty habit of repaying your overheating with lifting traces, pads and through-hole plating.

[DrGonz78]

Yeah I figured this board was going to be the toughest to work on that I have encountered yet. So many tools to buy at this stage in the game, but it is great how much you can do on a shoe string budget. This one might be something to either learn on once I get the proper tools or a pro might need to be involved. Thanks for the feedback.

[Jazz P Bass]

I just repaired a GK 700 RB.
I was amazed at the goofy layout of the pads & traces.
I think a beginner laid these PCB boards out.
This is not the amplifier to "learn" on.
You won't get a second chance to get it right because of the tiny pads & thin traces.

[Enzo]

If you play guitar, you can listen so some Credence Clearwater recording and think "well hell, I can play that." And you probably can. Then listen to some Yes tune of that era. Can you play along with that? Or Eddie Van Halen? Like any other skill, soldering and desoldering is learned, and some of it is a lot more complicated than the basics.

There is removing the old parts and there is cleaning out the old solder. SOmetimes we can do both in one step. But that doesn't change the fact it is two proccesses. Ther are techniques to learn. There are tools to have.

As Bill suggested, one way to remove a part is to clip it off, leaving its legs. You can then heat and pull each leg out of the hole, then when they are gone, go back and clean the solder from the hole. That will often work better than trying to get the solder out of the hole with the leg still there, and the whole transistor trying to suck the heat away.


Every tool has its fans. A lot of guys swear by desoldering braid. I absolutely hate the stuff. Some guys like the squeezy bulb desolderers. I am not a fan of those. Then there are the cylindrical cock it and press the button desolder pumps. I like those and have a couple sitting around. Good for the occasional joint or two. But absolutely nothing works like a desoldering station - a soldering iron with a hollow tip hooked up to a suction pump. Of course a desoldering station can;t be bought for $5 like a spool of braid. But then it costs more to hire Eddie Van Halen than it does to hire John Fogerty.

And one little tip: When you can get part of the solder out of the hole, but some wants to stay behind, ADD some fresh solder. Refill the hole with fresh solder and then suck the hole clean. It is kind like a dry sponge doesn;t pick up water as well as a sponge we moisten first. Oh, maybe it isn;t like that, but I like the analogy.

ANother lesson is to use enough heat. Turning the iron way down and being timid with it is MORE likely to damage traces than just getting right on it with a good hot iron.

[DrGonz78]

Each stage of soldering I have gone back and bought new irons. Did not want to buy the best at first figuring I might not use it w/ proper care. Now I am getting better at soldering so I have a decent one now. I use the pumps for the larger joints and finish it off w/ some solder wick. Sometimes I avoid the pumps if the PCBB board looks like it is older or more ready to crack. I think it is now time to find a decent de-soldering station for these times where the other tools won't work as good.

I do not like lead free solder at all, as I am pretty sure that is on this Traynor amp I am working on. Either that or it is really cold solder. Anyhow, I figured out that adding molten solder to the really hard solder causes it get more pliable quicker.

Yes those GK boards are not made to be repaired easily. However, they are built to withstand heavy bass vibrations so I would expect them to be soldered to stay together as best as possible. But this is just ridiculous. I got the amp for $35, so this might be the best time to learn how to solder this type of PCB. Either way I have a nice cabinet to fill, lol. I will be reserved and very careful on the amp as I learn too.

Thanks again guys! This is confirmation that I should invest into a very useful tool. Are there one's to avoid? I want something that is around $100.