Search found 15 matches

by denmla
Sat Jan 16, 2021 1:36 am
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Yes I'm sure as it was replaced as mentioned and synth works. No other parts were replaced.
by denmla
Thu Jan 14, 2021 3:10 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

No it is 560 kOHM one in place of the blue one I'm showing in the image.
by denmla
Wed Jan 13, 2021 11:06 am
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

No, the volume level is good but one channel (Right) has a slight (-50dB) hum to it.

It's aaaallive :) :)
by denmla
Tue Jan 12, 2021 9:30 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Prophecy is alive! Control resistor in place of this little blue R2 resistor went and synth would go to sort of safety mode. Replaced with new and all works. https://i.ibb.co/L8Lm393/Faulty.jpg Thanks everyone and esp Yekuku for helping out and hopefully somebody in the future will learn something f...
by denmla
Mon Jan 11, 2021 10:00 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

I see, thanks a lot. We'll check/replace and I'll report back!
by denmla
Mon Jan 11, 2021 12:05 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

This is the service manual but I cant find PSU schematic there:
https://www.synthxl.com/wp-content/uplo ... manual.pdf

Part is called "KLM-1856" and there is no schematics of it in the service manual....crasy
by denmla
Sun Jan 10, 2021 10:52 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Sure enough! Lot of potential hazard there... Yeah, once booted all the voltages are good (15V, 5V), synth plays works in a usual manner. So something is causing that initial voltage drain and it's not Capacitors (all tested and good) diodes (all tested and good) or FET switcher (tested and good). M...
by denmla
Sun Jan 10, 2021 8:14 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Hi Yekuku, I've got some great news! My good friend who is great with stuff like this did one really clever thing. He connected the mainboard AFTER turning on the synth...AND everything works! He also checked for all the Capacitors and they are all good as wel as the FET switcher and diodes.... So w...
by denmla
Sun Jan 10, 2021 4:42 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Awesome Idea.

Sure enough I'll get to electro shop to get loads and to measure current draw from PSU.

I=U/R cant be simpler than that!

Thanks man, will report back once I got the results.

:)
by denmla
Sun Jan 10, 2021 1:45 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Yes man that is correct! Squeal is produced by the transformer: https://i.ibb.co/QN0thFM/Transformer-Squeal.png When I disconnect the mainboard it goes away. Here is the KORG Prophecy service manual: https://www.synthxl.com/wp-content/uploads/2018/04/korg-prophecy-service-manual.pdf Thanks you so mu...
by denmla
Sun Jan 10, 2021 11:07 am
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Thank you so much. Bad news still helps as I'll be hunting for main board insteand of PSU if determine that is the way to go.... Generally speaking, we can continue even if that means further damage to the unit as it is better than "status quo" but surely can wait a bit more. So connecting the mainb...
by denmla
Sun Jan 10, 2021 10:25 am
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Hi Yekuku, thanks again for helping out! I did measure in both cases, WITH and WITHOUT mainboard connected: 1. Mainoard DISCONNECTED: - orange to black == 15V - red to black == 5.2V 2. Mainboard CONNECTED: - orange to black == 5.9V - red to black == 1.7V Also, I recorded the video of the powerup and...
by denmla
Sat Jan 09, 2021 1:48 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Guys, thanks a lot for tuning in!

@Ashe37 - it's quiet, turn up the loudnes or put it to 720p on YT, maybe its filtering the top end. Its igh up 15kHz+

@Yekuku - Orange to black (both) is 15V exact (15.007 V)! What would that point to?

Thanks, I really apprechiate the help!
by denmla
Sat Jan 09, 2021 8:44 am
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Re: Sudden Death - KORG Prophecy

Hi meatball fulton, thanks for tuning in! No you are not tripping, KOG Wavestation has that problem of simillar buzzing sounds comming from display area. However, as far as I'm able to accoustically locate the sound source it is definitely comming from the PSU, and ONLY when PSU is connected to the ...
by denmla
Fri Jan 08, 2021 10:25 pm
Forum: HELP!
Topic: Sudden Death - KORG Prophecy
Replies: 31
Views: 6499

Sudden Death - KORG Prophecy

Hi to all, I’m new here! Few moments ago my beloved Prophecy died - it wont turn on. Pressing the power button only makes a small light change in button color but LCD does not power up. Very very quiet but high pitched squeal/noise is heard From the PSU area while turned on. The sound keeps going un...