Latest eBay purchase: Ibanez FLL “spares or repair”

[Dinosaur_Sr]

Hey fellows, I took a plunge on eBay based on the description “This is a vintage Ibanez FLL Flanger made in Japan. Faulty and I don't know what is wrong with it. Suitable for parts or repairs. Could be an easy fix but I am not sure”

Well buddy, I do not think this is an easy fix but I think I can see what the problem is...

https://imgur.com/a/pPA70NT

I’m going to go ahead and assume this entire thing is completely fubar, that black bubbling on the board does not look healthy. What do you guys think, is there any hope of salvaging this or should I just bin it?

[Frank_NH]

I've been trolling for non-working pedals on eBay and Reverb.com for a while, and have seen everything from a simple switch fix (EHX East River Drive, MXR Dynacomp) to a reverse polarity burnt diode + damage to ICs (vintage Ibanez RC99).  I've been able to fix most of them, but you have to be patient.  The only way I'd toss it is if the circuit board traces were entirely ruined (cracked, cut).

First, see if you can find the schematic for the pedal.   Next, use baking soda to clean up the gunk left by the old battery.  Use your multimeter to see if the battery clip is still connected to the main board, and also check some basic connections.  Then try applying power to see if it works - if not, you'll have to check the voltages to see where the problems are.  Be prepared to replace some components such as blown ICs, capacitors, transistors, diodes, trimpots etc.  Usually resistors are pretty hardy and don't need replacement.

If it is beyond reasonable repair, try harvesting the ICs and toss the rest.  Good luck!

[Dinosaur_Sr]

Thank you for your reply man, this is excellent. Looks like I’ll be strapping in for a real adventure this time!

One question though, how should I apply the baking soda?

[Frank_NH]

You can make a thin paste with some clean water and use a toothbrush to gently scrub the area.  Try not to lift any traces - if you do the PCB may be ruined (but then it probably wasn't fixable all along...).

NOTE!

I just realized that your battery may be an alkaline type - if so, here are some instructions for clean up.  It calls for using a weak acid (e.g. vinegar) to neutralize the alkaline electrolyte.

http://alkalinebatteries.blogspot.com/2011/02/clean-up-after-alkaline-battery-leak.html

[Dinosaur_Sr]

Fantastic, thank you so much!

[Frank_NH]

See my previous response regarding the clean-up.

[Dinosaur_Sr]

ah ok cool, thanks again man

[Dinosaur_Sr]

follow up for anyone interested:

Almost gave up but I got it working! No retreat, no surrender.

Luckily the battery damage didn't affect the majority of the components, hell of a clean-up job though.

So I started with the obvious damage; a badly corroded trimmer. Next I realised that the switch wasn't working at all after I was able to get the LED lit by bridging the contacts. I carefully took it apart and the tiny copper plates inside were corroded too, but I was able to carefully take it apart and sand them shiny, took a few attempts to rebulid but I finally nailed it. The effect turned on but was just passing a clean signal, hmm.

After probing I thought that the MN3102/MN3207 might be fried, so I started removing them and yea, a couple of the 3102 legs had rotted right off inside the holes! Luckily I had another one laying around.

Last thing was a capacitor which wasn't reading any voltage on the positive leg, replaced that and the sucker came to life.

I feel like I could take on a medium-sized hippopotamus right now.

[Frank_NH]

Nice!  Always cool when the effect works after replacing the "magic" part.

What did you use to clean up the battery corrosion?  I'll have to remember that most batteries these days are alkaline and require a different cleanup than older battery types.