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Werkstatt has stopped functioning

Posted: Tue Nov 04, 2014 7:11 pm
by arjanhoekstra
Hi,

My Werkstatt will not switch on as of today. Nothing happens when I plug it in. I have tried to measure a few points but really this goes beyond my expertise. Anyone able to help me or share some tips on how to resolve this problem? They will be greatly appreciated. Thank you.

Re: Werkstatt has stopped functioning

Posted: Tue Nov 04, 2014 10:00 pm
by grenert
Has the Werkstatt been modded?
Do you know the power supply is working? If you have a multimeter, check that it is putting out 12V as expected.

Re: Werkstatt has stopped functioning

Posted: Tue Nov 04, 2014 11:08 pm
by muksys
Are you using the power supply that came with the Werkstatt or a different one? I've killed 2 Werkstatt's and found that I was accidentally powering it with 9VDC from my benchtop power supply. The fix was replacing a burned out resistor. Check at R17 which is a 4.99k resistor. It'll look burnt if it's dead. Other than that do what grenert suggested my making sure the power supply is outputting 12VDC.

When you say nothing happens, does that mean the LFO LED doesby light up?

Re: Werkstatt has stopped functioning

Posted: Wed Nov 05, 2014 12:24 am
by arjanhoekstra
Thank you grenert and muksys.

grenert wrote:Has the Werkstatt been modded?
Do you know the power supply is working? If you have a multimeter, check that it is putting out 12V as expected.


The workstatt has not been modded nor been tampered with. All that's been done to it is I've added a jumper cable to one of the pcb screws just like is shown in the video's on the werkstattworkshop website. I am using it's original power supply which measures an output of 12.16 Volt DC current.

muksys wrote:When you say nothing happens, does that mean the LFO LED doesby light up?


Yes, exactly that. No LED light and no sound coming from the Werkstatt.

At R17 I measure 29.4 the reading seems to vary between 24 and 30 at random. I've taken a picture, does it look burned?
.JPG
Werkstatt pcb R17

IMG_2007.JPG
Reading at R17

I also measured 12.3 Volts with the black probe at center+ (15) and red at the one below. But when the red probe is moved over to TP15/16 I get a reading of 1.637

Thanks guys

Re: Werkstatt has stopped functioning

Posted: Wed Nov 05, 2014 9:20 am
by muksys
A resistors value can't be measured when it's part of a circuit. R17 needs to be removed to test it. It's hard to tell in the picture but it does look a little toasty.

The way to check the voltages is to stick the black probe on tp11 or 13 and use the red to test the different voltages. Positive voltages will read 12, 9 or 5. Negative voltages will read -9. Make sure you have the probes plugged into their corrisponding terminals on the meter. The black should be plugged into to COM port.

Re: Werkstatt has stopped functioning

Posted: Wed Nov 05, 2014 9:27 am
by bichuelo
I'm no expert but it looks burnt to my sight

Re: Werkstatt has stopped functioning

Posted: Wed Nov 05, 2014 10:03 am
by grenert
muksys wrote:Check at R17 which is a 4.99k resistor.

Just a clarification, this resistor should be 4.99 ohms, at least according to the schematic (and the resistor itself looks to be marked 4R99).
With the power supply plugged in, put the ground lead (black) of your meter on a ground test point. Then put the red lead first on the left terminal of the resistor and measure DC volts. It should be around 12V. Then move the red lead to the right end of the resistor. It should still be around 12V.

Re: Werkstatt has stopped functioning

Posted: Wed Nov 05, 2014 11:54 am
by arjanhoekstra
muksys wrote:A resistors value can't be measured when it's part of a circuit. R17 needs to be removed to test it. It's hard to tell in the picture but it does look a little toasty.


I agree with you there it does look a little toasty.

muksys wrote:The way to check the voltages is to stick the black probe on tp11 or 13 and use the red to test the different voltages. Positive voltages will read 12, 9 or 5. Negative voltages will read -9. Make sure you have the probes plugged into their corrisponding terminals on the meter. The black should be plugged into to COM port.


So I've just measured all voltages the way you've described. +12 reads 1.637vdc. +9 reads 0.231vdc. -9 reads -2.050. +5 reads 0.591vdc. Anything else I should look at?

grenert wrote:
muksys wrote:Check at R17 which is a 4.99k resistor.

Just a clarification, this resistor should be 4.99 ohms, at least according to the schematic (and the resistor itself looks to be marked 4R99).
With the power supply plugged in, put the ground lead (black) of your meter on a ground test point. Then put the red lead first on the left terminal of the resistor and measure DC volts. It should be around 12V. Then move the red lead to the right end of the resistor. It should still be around 12V.


Just done exactly as you say. Measuring 1.636 on the left side and 11.90 on the right side of the resistor.

Thanks guys, much appreciated

Re: Werkstatt has stopped functioning

Posted: Wed Nov 05, 2014 12:11 pm
by muksys
Yep, my mistake. It's 4.99 ohms. Sounds like it's dead. If you're not comfortable with doing SMD desoldering, this is something I can fix for you if moog won't warranty it.

Re: Werkstatt has stopped functioning

Posted: Fri Nov 07, 2014 9:54 am
by Control_Voltage
Hi there,

Andy Hughes from Moog Music here!

If the Werkstatt has not been modded, we will of course be happy to perform this repair under warranty at no charge, and give the unit a full test to make sure there is not a fault somewhere else on the board that caused the resistor to burn, and we will check your PSU as well.

Please contact me at [email protected] or by phone (828)251-0090 xt. 221

Thanks,
Andy Hughes
Tech Support Manager
Moog Music, Inc.

Re: Werkstatt has stopped functioning

Posted: Sun Nov 09, 2014 12:18 pm
by grenert
muksys wrote:Are you using the power supply that came with the Werkstatt or a different one? I've killed 2 Werkstatt's and found that I was accidentally powering it with 9VDC from my benchtop power supply.

Wow, I almost just did this exact same thing. :shock:
Fortunately, I have enough experience frying circuits that I smelled that something was wrong and pulled the power supply before the resistor was fully fried.
I haven't really looked at the Werkstatt power supply circuit, but what a weird thing that giving a LOWER voltage to a device causes problems!

Re: Werkstatt has stopped functioning

Posted: Thu Nov 27, 2014 11:35 am
by arjanhoekstra
This issue has been resolved. Thanks to everyone posting in this thread and the excellent service at Moog music.

Re: Werkstatt has stopped functioning

Posted: Sat Nov 29, 2014 12:03 am
by muksys
arjanhoekstra wrote:This issue has been resolved. Thanks to everyone posting in this thread and the excellent service at Moog music.


What ended up being the issue?

Re: Werkstatt has stopped functioning

Posted: Sun Nov 30, 2014 4:29 pm
by arjanhoekstra
Burned resistor at R17. I don't know how this has happened, as mentioned, no modifications where done to the Werkstatt.

Re: Werkstatt has stopped functioning

Posted: Sun Nov 30, 2014 8:42 pm
by muksys
Interesting. That resistor is sensitive. I've fried it out from using a wrong power supply to shorting contacts to ground. I've never had a PS on a syth with such a sensitive part. Seems like a bad design choice for something thats intended to be user modifiable.