uO_c 8hp ornament and crime.

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: lisa, luketeaford, Kent, Joe.

Post Reply
PabloSrNaranja
Learning to Wiggle
Posts: 22
Joined: Sun Dec 29, 2019 3:07 pm

Re: uO_c 8hp ornament and crime.

Post by PabloSrNaranja » Fri May 08, 2020 11:38 am

Neutron7 wrote:
Fri May 08, 2020 7:29 am
2DCFF605-0FC0-4050-82C3-7982AB9C6F32.jpeg

4.4v on the negative rail is not good!

can you check right on the - pin of the rectifier? (it looks like that pin could use a reflow as well)
This are the measures. I will also reflow.

Edited to avoid confussions. is 11,2V and minus 11,7 in the negative leg
You do not have the required permissions to view the files attached to this post.
Last edited by PabloSrNaranja on Fri May 08, 2020 1:28 pm, edited 1 time in total.

User avatar
Neutron7
Oldschool bleeper
Posts: 1948
Joined: Sun May 23, 2010 12:24 pm

Re: uO_c 8hp ornament and crime.

Post by Neutron7 » Fri May 08, 2020 12:22 pm

PabloSrNaranja wrote:
Fri May 08, 2020 11:38 am
Neutron7 wrote:
Fri May 08, 2020 7:29 am
2DCFF605-0FC0-4050-82C3-7982AB9C6F32.jpeg

4.4v on the negative rail is not good!

can you check right on the - pin of the rectifier? (it looks like that pin could use a reflow as well)
This are the measures. I will also reflow.
you sure the - on the rectifier is not minus 11.7v?

PabloSrNaranja
Learning to Wiggle
Posts: 22
Joined: Sun Dec 29, 2019 3:07 pm

Re: uO_c 8hp ornament and crime.

Post by PabloSrNaranja » Fri May 08, 2020 12:37 pm

Neutron7 wrote:
Fri May 08, 2020 12:22 pm
PabloSrNaranja wrote:
Fri May 08, 2020 11:38 am
Neutron7 wrote:
Fri May 08, 2020 7:29 am
2DCFF605-0FC0-4050-82C3-7982AB9C6F32.jpeg

4.4v on the negative rail is not good!

can you check right on the - pin of the rectifier? (it looks like that pin could use a reflow as well)
This are the measures. I will also reflow.
you sure the - on the rectifier is not minus 11.7v?

Oh sorry, my fault! Minus 11,7v i have edited the post to avoid future confusions in other users.

User avatar
Neutron7
Oldschool bleeper
Posts: 1948
Joined: Sun May 23, 2010 12:24 pm

Re: uO_c 8hp ornament and crime.

Post by Neutron7 » Fri May 08, 2020 2:18 pm

Annotation 2020-05-08 151720.png
do you still get -11.7v anywhere connected to this trace? if not then the -V rail is not connected to the rectifier. (or if it is a lower negative voltage, possibly a wrong component or short)
You do not have the required permissions to view the files attached to this post.

PabloSrNaranja
Learning to Wiggle
Posts: 22
Joined: Sun Dec 29, 2019 3:07 pm

Re: uO_c 8hp ornament and crime.

Post by PabloSrNaranja » Fri May 08, 2020 2:54 pm

Neutron7 wrote:
Fri May 08, 2020 2:18 pm
Annotation 2020-05-08 151720.png

do you still get -11.7v anywhere connected to this trace? if not then the -V rail is not connected to the rectifier. (or if it is a lower negative voltage, possibly a wrong component or short)
I found strange voltages. I understand that some voltage drop can happen, but not the inverted polarity.

Any clues?? something regarding the condenser? Really apreciate your help.
You do not have the required permissions to view the files attached to this post.

User avatar
Neutron7
Oldschool bleeper
Posts: 1948
Joined: Sun May 23, 2010 12:24 pm

Re: uO_c 8hp ornament and crime.

Post by Neutron7 » Fri May 08, 2020 8:58 pm

can you turn it off, then measure the resistance between the rectifier pin and the other points (one of the places you measured +4.4v) , then the resistance between the PAD for that pin and see if they are both the same.if they are not the solder joint might be bad.

if they are both very high, the only thing i can think of is a crack in a trace, but they can be hard to find!

PabloSrNaranja
Learning to Wiggle
Posts: 22
Joined: Sun Dec 29, 2019 3:07 pm

Re: uO_c 8hp ornament and crime.

Post by PabloSrNaranja » Wed May 13, 2020 3:28 am

Neutron7 wrote:
Fri May 08, 2020 8:58 pm
can you turn it off, then measure the resistance between the rectifier pin and the other points (one of the places you measured +4.4v) , then the resistance between the PAD for that pin and see if they are both the same.if they are not the solder joint might be bad.

if they are both very high, the only thing i can think of is a crack in a trace, but they can be hard to find!

I had reflown all the track, and finally archieve the -12 v on the opamp. Then I followed the 3,6V reference and I found that something was happening with C9, so I directly solder a resistor leg joint as shown in the picture.

After all everything is wotking just fine! I really apreciate your help. Thanks for the advices :yay: :yay:
You do not have the required permissions to view the files attached to this post.

User avatar
Neutron7
Oldschool bleeper
Posts: 1948
Joined: Sun May 23, 2010 12:24 pm

Re: uO_c 8hp ornament and crime.

Post by Neutron7 » Thu May 14, 2020 3:06 pm

nice, I am glad you got it going!

User avatar
jpeterman
Common Wiggler
Posts: 52
Joined: Tue Aug 20, 2019 1:25 pm
Location: los angeles

Re: uO_c 8hp ornament and crime.

Post by jpeterman » Tue May 26, 2020 6:58 pm

Are there any equivalents that can be used for the TT encoders? https://www.mouser.com/ProductDetail/858-EN11-HSM1BF20

They are out of stock and won't be back in stock until August.

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Thu May 28, 2020 3:35 pm

Dear colleagues,

I have finished a uO_C build and have a big trouble : i have zero volts in every output when calibrating :doh:

The reason behind is very plausibly related to the fact that i fried a teensy before getting there... I tried to power it on while some flux residue wasnt dry and the teensy board shorted. There wasnt flux elsewhere so i thought that replacing the teensy would suffice, but im afraid it doesnt, maybe some current went into a part of the circuit it shouldnt... Im wondering where i can try to test the voltage (and what im supposed to get) to narrow where is the issue, can you maybe help me?

i double checked my solderings, they look good (based on my standards), and the display lights up and i can scroll inside the menu without an issue (so the encoders are good also). The fact that i have the same zero volt in every output would suggest there is a component they have in common that is not doing its job, but it could as well be something else of course. On the naked eye there is nothing suspicious as far as i can see.

Any help is welcome! Thanks in advance!

pic link : imgur.com/gallery/CBj1rhN
You do not have the required permissions to view the files attached to this post.

User avatar
Neutron7
Oldschool bleeper
Posts: 1948
Joined: Sun May 23, 2010 12:24 pm

Re: uO_c 8hp ornament and crime.

Post by Neutron7 » Fri May 29, 2020 7:15 am

if the display is working, and the encoder is working, chances are the teensy is ok. if no outputs are working but gate and cv inputs are working, it could be the DAC. if no outputs and no inputs, then it could be power related, that is pretty much all they have in common. the top left 2 pins of the DAC in your picture have some solder between them, could it be a short?
Last edited by Neutron7 on Fri May 29, 2020 7:27 am, edited 1 time in total.

User avatar
Neutron7
Oldschool bleeper
Posts: 1948
Joined: Sun May 23, 2010 12:24 pm

Re: uO_c 8hp ornament and crime.

Post by Neutron7 » Fri May 29, 2020 7:24 am

jpeterman wrote:
Tue May 26, 2020 6:58 pm
Are there any equivalents that can be used for the TT encoders? https://www.mouser.com/ProductDetail/858-EN11-HSM1BF20

They are out of stock and won't be back in stock until August.
digikey has bourns PEC11R-4220F-S0024 they might be reversed, but o_c has an option to reverse encoders, the "F" means flatted D shaft, you can change it to "K" for t18 knurled knobs.
Last edited by Neutron7 on Sat Jun 06, 2020 10:22 am, edited 1 time in total.

simioliolio
1-Post Wiggler
Posts: 1
Joined: Tue Jun 02, 2020 3:14 pm

Re: uO_c 8hp ornament and crime.

Post by simioliolio » Tue Jun 02, 2020 3:24 pm

Can anyone see a problem using a Teensy 3.1 for this build? Reading here, the main difference seems to be:
"Teensy 3.2 adds a more powerful 3.3 volt regulator, with the ability to directly power ESP8266 Wifi, WIZ820io Ethernet and other power-hungry 3.3V add-on boards.

User avatar
peteone
Wiggling with Experience
Posts: 465
Joined: Fri Feb 07, 2014 12:06 am
Location: Los Angeles, CA

Re: uO_c 8hp ornament and crime.

Post by peteone » Wed Jun 03, 2020 10:27 am

Accidentally plugged teensy wrong way, smoke from around power socket, cant locate exactly where, OLED is not working. Any help?
uO_c Micro

User avatar
emmaker
Veteran Wiggler
Posts: 625
Joined: Sat Mar 10, 2012 5:07 pm
Location: PDX

Re: uO_c 8hp ornament and crime.

Post by emmaker » Wed Jun 03, 2020 3:51 pm

peteone wrote:
Wed Jun 03, 2020 10:27 am
Accidentally plugged teensy wrong way, smoke from around power socket, cant locate exactly where, OLED is not working. Any help?
uO_c Micro
1) Visual inspection under a strong light with a magnifier. Look for burnt components, burnt PCB and fried traces.
2) Smell the board, yes really. Might be able to actually isolate the component by this.
3) Pull the Teensy, plug it into a bench supply with current limit (or isolated supply, don't want to blow up your real synth supply) and start measuring voltages with a meter. I'd start with the voltage regulators on the board.
4) If the bench/isolated supply limits out unplug it and start ohm-ing things out with a meter.
5) Still haven't got it fixed. Salvage panel, switches, jacks and display, test them and recycle the rest of the module.

Jay S.

User avatar
peteone
Wiggling with Experience
Posts: 465
Joined: Fri Feb 07, 2014 12:06 am
Location: Los Angeles, CA

Re: uO_c 8hp ornament and crime.

Post by peteone » Wed Jun 03, 2020 4:47 pm

emmaker wrote:
Wed Jun 03, 2020 3:51 pm
peteone wrote:
Wed Jun 03, 2020 10:27 am
Accidentally plugged teensy wrong way, smoke from around power socket, cant locate exactly where, OLED is not working. Any help?
uO_c Micro
1) Visual inspection under a strong light with a magnifier. Look for burnt components, burnt PCB and fried traces.
2) Smell the board, yes really. Might be able to actually isolate the component by this.
3) Pull the Teensy, plug it into a bench supply with current limit (or isolated supply, don't want to blow up your real synth supply) and start measuring voltages with a meter. I'd start with the voltage regulators on the board.
4) If the bench/isolated supply limits out unplug it and start ohm-ing things out with a meter.
5) Still haven't got it fixed. Salvage panel, switches, jacks and display, test them and recycle the rest of the module.

Jay S.
thanks!

User avatar
emmaker
Veteran Wiggler
Posts: 625
Joined: Sat Mar 10, 2012 5:07 pm
Location: PDX

Re: uO_c 8hp ornament and crime.

Post by emmaker » Thu Jun 04, 2020 3:16 pm

peteone wrote:
Wed Jun 03, 2020 4:47 pm
emmaker wrote:
Wed Jun 03, 2020 3:51 pm
peteone wrote:
Wed Jun 03, 2020 10:27 am
Accidentally plugged teensy wrong way, smoke from around power socket, cant locate exactly where, OLED is not working. Any help?
uO_c Micro
1) Visual inspection under a strong light with a magnifier. Look for burnt components, burnt PCB and fried traces.
2) Smell the board, yes really. Might be able to actually isolate the component by this.
3) Pull the Teensy, plug it into a bench supply with current limit (or isolated supply, don't want to blow up your real synth supply) and start measuring voltages with a meter. I'd start with the voltage regulators on the board.
4) If the bench/isolated supply limits out unplug it and start ohm-ing things out with a meter.
5) Still haven't got it fixed. Salvage panel, switches, jacks and display, test them and recycle the rest of the module.

Jay S.
thanks!
I'd like to amend this.

If you get to step 3 and everything is good. I'd put another Teensy in and see what happens.

DO NOT FORGET TO CUT THE TEENSY POWER TRACE!

Jay S.

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Sat Jun 06, 2020 5:53 am

Neutron7 wrote:
Fri May 29, 2020 7:15 am
if the display is working, and the encoder is working, chances are the teensy is ok. if no outputs are working but gate and cv inputs are working, it could be the DAC. if no outputs and no inputs, then it could be power related, that is pretty much all they have in common. the top left 2 pins of the DAC in your picture have some solder between them, could it be a short?
the DAC should be ok, i dont see any bridge but re-fluxed for certainty. indeed it seems to be the power; i could see that R60 was popped out, i replaced it, and the new one became red hot while powered. So i guess we need to see what gives it too much.

looked at the diagram, it could be coming from
-wrong orientation on diode bridge??
-C1/C2 not doing their job?
-"VEE"? this voltage comes U3, U4 (opamps) and U6 (lm4040).

Any idea how i can test this or something else I could check?
Many thanks!!



User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3401
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Re: uO_c 8hp ornament and crime.

Post by Altitude909 » Sat Jun 06, 2020 6:32 am

the 4R7 is going up because you have a power rail short somewhere. Check resistance on the 3V3 and 5V to ground, whichever one is super low, thats the one thats shorting and check along those traces

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Sat Jun 06, 2020 7:07 pm

Altitude909 wrote:
Sat Jun 06, 2020 6:32 am
the 4R7 is going up because you have a power rail short somewhere. Check resistance on the 3V3 and 5V to ground, whichever one is super low, thats the one thats shorting and check along those traces
thank you!! when checking i found that C32 was connected to the ground both sides -im no expert but this sounds bad i guess. on the diagram its only connected to ground and the +3.3V. i guess i need to replace it, is that what you had in mind? whats the use of that part by the way?

on the dac the multimeter says theres a bridge between the 2 last pads, i tried to correct this but unsuccesfully so far. apparently they both go to ground, im not sure i need to take action actually... i checked the datasheet for their role, i guess we dont care:
15 ENABLE The enable pin (active low) connects the SPI interface to the serial port
16 LDAC Load DACs; rising edge triggered, loads all DAC register
Last edited by atch3000 on Sat Jun 06, 2020 7:13 pm, edited 1 time in total.

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3401
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Re: uO_c 8hp ornament and crime.

Post by Altitude909 » Sat Jun 06, 2020 7:10 pm

that only means that your 3v3 is shorted to ground somewhere, not necessarily there

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Sat Jun 06, 2020 7:23 pm

Altitude909 wrote:
Sat Jun 06, 2020 7:10 pm
that only means that your 3v3 is shorted to ground somewhere, not necessarily there
agreed, but all the others in int same situation (one side to ground, one to +3.3) are only beeping on only one side, this one does it consistently on both. im checking with just a continuity tester, is it enough?

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Sun Jun 07, 2020 4:54 pm

atch3000 wrote:
Sat Jun 06, 2020 7:23 pm
Altitude909 wrote:
Sat Jun 06, 2020 7:10 pm
that only means that your 3v3 is shorted to ground somewhere, not necessarily there
agreed, but all the others in int same situation (one side to ground, one to +3.3) are only beeping on only one side, this one does it consistently on both. im checking with just a continuity tester, is it enough?
indeed its not that...lets check further...

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Fri Jun 12, 2020 2:42 pm

atch3000 wrote:
Sun Jun 07, 2020 4:54 pm
atch3000 wrote:
Sat Jun 06, 2020 7:23 pm
Altitude909 wrote:
Sat Jun 06, 2020 7:10 pm
that only means that your 3v3 is shorted to ground somewhere, not necessarily there
agreed, but all the others in int same situation (one side to ground, one to +3.3) are only beeping on only one side, this one does it consistently on both. im checking with just a continuity tester, is it enough?
indeed its not that...lets check further...
found a ground bridge on the U7 and corrected, now the R60 still warms crazy, but no more display either for some reason! i feel like progressing backwards :cry:

atch3000
Learning to Wiggle
Posts: 12
Joined: Wed Sep 04, 2019 5:27 pm
Location: Belgium

Re: uO_c 8hp ornament and crime.

Post by atch3000 » Tue Jun 16, 2020 11:51 am

hello guys,
so i was actually building two units, i was awaiting thonk for the jacks fo the other one. i received them today and : zero volt when doing the calibration again! i have built both in parrallel so apparently i did the same mistake on each. here i have no heat on R60 and no short on the C32, so i had good hopes. But still the same zero. Coudl anyone provide me reference voltages i could measure across the circuit to locate the wrong component?


Post Reply

Return to “Music Tech DIY”