MXR Flanger 117 map required

[blindboybenton]

Hello all
A bit of a long shot. Got a MXR Flanger 117 with no effect but working bypass
I have the original map but there don't seem to be a 117 version available ?
if anyone can assist i would be truly grateful

have a good day

BBB

[dmeek]

Here is the M-117 schematic. Which version schematic do you have?

https://music-electronics-forum.com/...1&d=1571150504

[blindboybenton]

thanks Dmeek . im not sure. not the version above
it says MXR 117 version 2 on it


bbb

[dmeek]

That's the newer series. I don't have a schematic for that one. The MN3204 chip is the bbd delay, pin 3 is input. other than that these SMD boards are very hard to trace without a schematic.
Check that you have +5V or more on MN3204 pin 5

[vintagekiki]

https://www.scribd.com/document/369047600/MXR-117-Flanger-Service-Schematic

https://drive.google.com/file/d/1vpHJanRoGtZgz-OA0p3wA4mDucRT0-ca

http://falseelectronics.blogspot.com/2017/06/mxr-evh-flanger.html

https://www.schematicsunlimited.com/m/mxr/mxr-m-117r-flanger-pedal-schematic

[blindboybenton]

thank you... I have searched the internet and checked out all these before i post a request .Hoping that someone might have one, but again none of these are about the model i have
BBB

[blindboybenton]

thanks i will check that out
bbb

[Mark Hammer]

When you say "no effect", do you mean no signal at all, or do you simply mean no flanging effect? Both are possible, but have different causes.

Though not always the case, disappearing flanger or chorus effects can often occur because of a miscalibrated trimmer. All bucket-brigade devices, regardless of what they are used for, require a DC bias voltage at their input. If the voltage is set too high or too low, no audio signal will pass. Adjusted a little high or a little low, signal will pass, but will be distorted and less than maximum volume. In the case of the MN3204, that trimmer will be tied to pin 3, usually through a fixed resistor. It is possible to play with the bias setting, without risking damage to the delay chip.

The trimmer closest to the MN3204 might be the bias trimmer, but I'm not absolutely sure. There is often a second trimmer connected to the output of a BBD (in this case, pins 7 and 8), which adjusts the relative balance/level of the two parallel outputs of the chip, so as to minimize clock noise. And that trimmer close to the chip might be it. One way to verify is to check for continuity between pins 7 and 8 and the two outside lugs of that trimmer.

The reissue board you show has some changes which make it diverge from the original schematic a bit. Not necessarily tonally, but in terms of the specific circuitry required. So I don't know , or rather can't be certain, about which trimmer corresponds to which in the original schematic.

[blindboybenton]

There was bypass and when you switched over to effect. led came on but no signal at all.
tried to trace the signal but i have to admit. No schematic its hard for me.

BBB

[Mark Hammer]

Do you have some means to bypass the bypass circuit? IN other words, to feed the input jack to the circuit input and circuit output to output jack.

[blindboybenton]

not sure mark. to be honest im going to leave this one. I just don't get enough time to do the jobs as it is
thanks for the help, without the map i won't waste my time
many thanks
BBB