Ibanez Flanger (FL9) not Flanging

[Cardboard Tube Samurai]

I bought a cheap, not working flanger and need to know where to start looking. Basically, sound gets though fine, even when effect is engaged, but when it's on, there's no discernible change to the sound. I'm aware of the debugging guide etc but if there's a commonly known or recurring fault with them to which I am not yet privy, could someone please enlighten me?

[composition4]

Try checking to see if the LFO is working.  I fixed an Ibanez Chorus/Flanger CF7 last week with the same symptoms and the problem was that the LFO wasn't oscillating

Jonathan

[Cardboard Tube Samurai]

That certainly narrows it down, cheers. The guy said he'd had it looked at and "the chip was busted". There are five chips in it so the LFO narrows it down nicely. Now I just have to wait for 3 weeks to get the part from overseas because Australia is so crap for buying parts

[composition4]

I'd measure the voltage of the output of the LFO on a slow speed to see if it is oscillating correctly before replacing the IC. Could be a couple of other things too but replacing the opamp is a start.

If you have an LM358 then that'll work fine in place of TL022, both are low power opamps.  If you don't have an LM358, PM me your address and I'm happy to send you a couple on Monday (I'm in Perth), I've got heaps spare

Jonathan

[Cardboard Tube Samurai]

Thanks Jonathon, that's a mighty generous offer but I'll pass it up. I think I have a couple of LM358s lying around too.

[Cardboard Tube Samurai]

So it wasn't the LFO opamp. Unfortunately, I've popped the fuse on my multimeter so I can't do any testing at the moment. I really should just get off my arse and go to Jaycar today

[oldschoolanalog]

Take V readings.
Audio probe it.
Report back (w/link to schematic please).
Thank You.

[Lurco]

http://www.mojotronics.com/images/FL9.pdf

[oldschoolanalog]

Thanks for the nice link! Calibration instructions too...
Have you tried fiddling w/the bias trimpot yet?

[rrroo]

this may not help the original poster anymore, but in case anybody else searches for help in this i thought i'd dshare my experience.

i have had two FL9 pedals with this same problem (i bought them cheap, because of the fault). in both cases the problem was the two electrolytic caps in the LFO had gone bad, leaked. this was easy to notice because i could see some corrosion around these caps. they were the yellow caps, noticeably different than the other caps in the pedal.  if there is no flanging effect but signal goes through, try changing these caps first. it's easier and cheaper than chancing the chips.