Dear Ryuichi,

thank you for the kind words. You may also measure the voltage directly at
the LED. It should change the polarity when the direction changes. If that's
true I'm quite sure that the LED is faulty. Otherwise it's another problem.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com [mailto: Doepfer_a100@yahoogroups.com ]
> Gesendet: Mittwoch, 15. Februar 2017 13:57
> An: Doepfer_a100@yahoogroups.com
> Betreff: Re: 1 A-110-4: LED for negative part is OFF most
> of time
>
>
> Dear Dieter,
>
> Thank you very much for the suggestion. As a weekend DIYer, I have
> built a handful of thru-hole-component modules. So I will definitely
> try to replace the LED (of course, before doing that, I will collect
> information to make sure that I should be really skeptical about it).
>
> Doepfer oscillators are always my first choice to play with me. I
> really love your products. Thank you for producing A-100 modules, and
> I am looking forward to seeing the new 110-6 oscillators!
>
> Best Regards,
> Ryuichi Tamura
>
>
> 2017-02-15 17:48 GMT+09:00 yahoo@... 1
> < Doepfer_a100@yahoogroups.com >:
> > Sounds to me like a defective LED. If you are familiar with
> soldering and
> > electronics you may try to replace the LED by another dual type, e.g.
> > red/green or red/yellow (the white/blue dual LEDs are hard to
> find and is a
> > custom made product).
> >
> > Best wishes
> > Dieter Doepfer
> >
> >> -----Urspr�ngliche Nachricht-----
> >> Von: Doepfer_a100@yahoogroups.com [mailto: Doepfer_a100@yahoogroups.com ]
> >> Gesendet: Mittwoch, 15. Februar 2017 01:14
> >> An: Doepfer_a100@yahoogroups.com
> >> Betreff: Re: 1 A-110-4: LED for negative part is OFF most
> >> of time
> >>
> >>
> >> Dear Dieter,
> >>
> >> Thank you very much for your kind reply. Yes, with no signal being fed
> >> in LFM, the led of my 110-4SE does not light up in white for LFrq
> >> positioned in the negative range. This is the issue of my unit
> >> (although the FM sound from it seems fine..) Following your insight,
> >> my unit is still defective. So I will have to find a way to repair it.
> >> Thanks again for your support.
> >>
> >> Best Regards,
> >> Ryuichi Tamura
> >>
> >> 2017-02-13 21:24 GMT+09:00 yahoo@... 1
> >> < Doepfer_a100@yahoogroups.com >:
> >> > Hello,
> >> >
> >> > without external LFM signal the LED should light up white when
> >> you turn the
> >> > LFrq knob CCW. When you turn the LFrq knob CW the LED should
> light blue.
> >> > Otherwise the module is defective and has to be repaired.
> >> > As soon as an external LFM signal is applied the blue/light
> >> share depends
> >> > upon the position of the LFrq knob and the LFM level.
> >> >
> >> > Best wishes
> >> > Dieter Doepfer
> >> >
> >> >
> >> >> -----Urspr�ngliche Nachricht-----
> >> >> Von: Doepfer_a100@yahoogroups.com
> [mailto: Doepfer_a100@yahoogroups.com ]
> >> >> Gesendet: Montag, 13. Februar 2017 09:00
> >> >> An: Doepfer_a100@yahoogroups.com
> >> >> Betreff: 1 A-110-4: LED for negative part is
> OFF most of
> >> >> time
> >> >>
> >> >>
> >> >> Hello there,
> >> >>
> >> >> This is my first post, and I am sorry for writing message
> as follows.
> >> >> But, I would like to have any advice or suggestion for my A-110-4SE,
> >> >> which seems to malfunction.
> >> >>
> >> >> A few months ago, I accidentally touched its circuit board while it
> >> >> was powered. Since then my A-110-4 did not generate the
> negative part.
> >> >> Specifically, with Lfrq knob being around the center, only the half
> >> >> (from the positive part) of modulation was heard. It
> sounded like "the
> >> >> half of the modulation is gone." The bicolor led was only
> lit in blue
> >> >> when the positive part is modulated.
> >> >>
> >> >> As I have no knowledge about the circuit, all I could do was to
> >> >> replace all ICs with the new ones, and I did. After
> replacing all the
> >> >> ICs, and all the calibration procedures documented in
> >> >> "A110_4_trimming_potentiometers.pdf" being done, the unit seemed to
> >> >> revert to its healthy state, in terms of the sound I heard.
> >> >>
> >> >> However, the led still does not work properly. The led is
> *rarely* lit
> >> >> in white. Currently, the led is either lit in blue, or off
> most of the
> >> >> time, and occasionally lit in white.
> >> >>
> >> >> So, my concern is that this irregular behavior the led may cause
> >> >> another trouble or fault. Is it ok to keep using it, or is
> there any
> >> >> part in the circuit I should investigate, or is it better to ask the
> >> >> Doepfer for repair
> >> >>
> >> >> Thank you very much.
> >> >>
> >> >> Regards,
> >> >> Ryuichi Tamura
> >> >>
> >> >>
> >> >> ------------------------------------
> >> >> Posted by: Ryuichi Tamura < ry.tamura@... >
> >> >> ------------------------------------
> >> >>
> >> >>
> >> >> ------------------------------------
> >> >>
> >> >> Yahoo Groups Links
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >> >
> >> > ------------------------------------
> >> >
> >> > ------------------------------------
> >> >
> >> >
> >> > ------------------------------------
> >> >
> >> > Yahoo Groups Links
> >> >
> >> >
> >> >
> >>
> >>
> >> ------------------------------------
> >> Posted by: Ryuichi Tamura < ry.tamura@... >
> >> ------------------------------------
> >>
> >>
> >> ------------------------------------
> >>
> >> Yahoo Groups Links
> >>
> >>
> >>
> >
> >
> >
> > ------------------------------------
> >
> > ------------------------------------
> >
> >
> > ------------------------------------
> >
> > Yahoo Groups Links
> >
> >
> >
>
>
> ------------------------------------
> Posted by: Ryuichi Tamura < ry.tamura@... >
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>