Re: Newbie trying to fix a Johnson FT-2 Tremolo Pedal (for guitar)



<Kotti75events@xxxxxxxxxxxxxx> wrote in message
news:097aae02-5230-459d-8a37-79da39984b01@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
PS: it was the D1 diode that I replaced. It was broken (had burst) and
there's also a burn mark on the perf board. A near by wire was also
singed but I replaced that. I don't have many tools and am new at this
sort of thing, so any help is greatly welcomed!

On Apr 30, 12:41 am, Kotti75eve...@xxxxxxxxxxxxxx wrote:
I'm trying to repair this pedal for a friend. There appeared to be
only one burnt out component and I replaced it but it still doesn't
work. It did look like something was spilled inside the pedal and I've
cleaned that out. When in bypass, the signal passing through is
distorted and garbled, like hearing it on a faint radio station. But
when the pedal is engaged, it doesn't pass signal at all. I'm pretty
certain that this is a copy of the Boss TR-2 because the schematic
seems to fit with the exception of the IC
chips.http://www.schematicheaven.com/effects/boss_tr2_tremolo.pdf
Since the "bypass/engage mode" is triggered by a momentary switch, and
the dry signal goes down a very processed chain of components, I
haven't been able to figure it out. What typically goes bad when there
are spills? From looking at this schematic, how would I go about
figuring out where in the "dry signal" chain things are wrong?

Thank you very much!

Olivia

D1 is in the line for the external power supply, if it burned out then
there's a high probability that the wrong power supply was connected to it;
unless you really want the challenge of fixing it, I would recommend your
friend buy a new pedal as many components are liable to have been damaged.
Sorry to be so pessimistic!
Martin
--
martin<dot here>whybrow<at here>ntlworld<dot here>com


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