You’re looking at my late 80’s, early 90’s Ibanez TS-9 Tubescreamer. It looks fine, but it wasn’t. Sorry if I haven’t taken any step-by-step photos, you’ll have to make due with prose some googled images. Top picture is my own- now working- Tubescreamer.
The problem was; the LED light didn’t work anymore: this can be very tedious, especially when playing live. Lazy as I am, I grew accustomed to it and just checked it by playing my guitar. Today it was quite rainy so I thought let’s whip out the ol’ soldering iron and check out what’s wrong with the LED light.
In my spare cupboard I found an old LED from a pocket flashlight of the right size in color red, tested it using a small flat button battery, it worked. I didn’t yet know for sure if the LED in the TS-9 was broken, loose connection or shorting circuit in the pedal, so off I went.I opened the pedal carefully, and unscrewed the print board.
Two wires come off the print board to a smaller separate board, to which the LED is soldered. A diode (a Light Emitting Diode) in this case, will only allow current to flow one way: this means that it will only function if connected in the right way. The pedal itself was working fine, only the LED didn’t light up. So I used the spare LED in my hand, testing it on the various connections until I saw it light up; conclusion; the electronics are still in tact; only the bulb itself was broken.
Now comes the fiddly bit; I unscrewed the smaller “LED print board”, it is held in place close to the hole where the LED protrudes through the face of the body, and carefully lifted it out and used my soldering-helper-buddy to clamp it in one of the crocodile clamps. I let the soldering iron heat up and coated it with a tiny bit of solder; this will prolong the life of your soldering iron, regardless if you need to add solder to your connection.
I had positioned the small LED print board with the LED facing down, so I could heat up both “legs” of the LED captured in two tiny drops of solder on the bottom of it. Carefully heating them (you don’t want the two drops to merge or “cook” the print board). You can spot the solder melting when it turns all shiny and silver instead of dull. Using my free hand, I pulled on the LED while heating the “legs” and bingo! It came loose without disturbing the two drops of solder on the print board too much: success.
With the broken bulb unsoldered, I could now solder in the new -working- LED. Having mentioned before that a diode only accepts current one way, I was sure to test the new bulb and mark one of the legs with a magic marker so I knew which leg went where. There are two tiny holes in this print board which accept the two LED legs.
I clamped the LED up side down in the soldering helper, and clamped the print board in the other crocodile clamp over it, and nudged the (precut) legs in the tiny holes.The tricky bit: heating up both solder drops, making sure they don’t melt together (which would short it out) and without “cooking” the print board, I applied gentle pressure to the new LED while heating up the solder and all of a sudden, it sank in, I lifted up the soldering iron and presto!
The LED was soldered in place. It pays to test it at this point, before closing up the pedal. Luckily the new LED lit up real well and the soldering connection appeared solid. Using a normal paper perforator, I punched a hole in a tiny ring of cardboard with a shiny silver side. I used this as a washer behind the LED as a reflector, which makes it a bit brighter.Then I screwed everything back together, there you go: a brand new functioning LED!
As some background info, here is a video how they “wave-solder” several components to one print board by hovering it over a “bath” of molten solder and generating a “wave” in the solder bath, which then touches the pins that protrude on the bottom of the print board, soldering all components in place in one go: http://www.youtube.com/watch?v=CH2tE9Wct4U