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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: October 04, 2015, 11:08:19 PM »
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17
preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: October 04, 2015, 11:07:19 PM »
Handheld pics ... not using a desktop capture app 
Pins 3,4,5 on the DAC side
The last 2 pics you sent, which pins are they representative of?
Pins 3,4,5 on the DAC side
The last 2 pics you sent, which pins are they representative of?
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: October 04, 2015, 06:29:57 PM »
Hi Xavier,
Nope, waiting until all paths are exhausted in troubleshooting before moving on to another build. I have hope that this one will work eventually. The socket removal was a bit of work, but the sockets come off safely (no pads harmed) if one carefully crushes the plastic around each pin carefully. This saves hitting the pads with a lot of heat for no reason. I have a pretty decent desoldering iron here too. Anyhow, it came out clean, and I wanted to see if any of the pads were somehow connected by excess solder underneath the sockets on the top side of the board. This was not the case. They had (still have) plenty of clearance.
Thanks for the tip on the 115k's .. I'll let them be. I'll look at the oscilloscope today too and compare your pics to the signals here.
Thank you for the pictures too! Maybe by the end of this thread, there will be some good troubleshooting tips for some other novice / future builder of the preenFM2.
Nope, waiting until all paths are exhausted in troubleshooting before moving on to another build. I have hope that this one will work eventually. The socket removal was a bit of work, but the sockets come off safely (no pads harmed) if one carefully crushes the plastic around each pin carefully. This saves hitting the pads with a lot of heat for no reason. I have a pretty decent desoldering iron here too. Anyhow, it came out clean, and I wanted to see if any of the pads were somehow connected by excess solder underneath the sockets on the top side of the board. This was not the case. They had (still have) plenty of clearance.
Thanks for the tip on the 115k's .. I'll let them be. I'll look at the oscilloscope today too and compare your pics to the signals here.
Thank you for the pictures too! Maybe by the end of this thread, there will be some good troubleshooting tips for some other novice / future builder of the preenFM2.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: October 04, 2015, 01:49:58 AM »
I just removed both DAC dip sockets, cleaned the pads nicely, and replaced the sockets with machined sockets. Also new DACs. Still no change. Same 3.85v on the DACs. Next I'm going to remove and replace every resistor and cap on the board. The only ones that look like they may be odd are the 115k resistors. I'll have to locate some though. My local electronics store didn't have any in stock. I have everything else here now.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 21, 2015, 09:31:28 AM »
Sounds good ... yes, the pops are perplexing. They don't happen every time though. Somewhat intermittent. They are in time / sync with the flashing LEDs on boot. Yes, the signal between preen and DACs are strong. I have the board layout to look at now. I'm going to carefully trace the full length of the audio signal path after DACs again. The 3.99v at the DACs 4.02v at the resistors seems like the best (only) clue so far. I tested midi via DIN again the other night too .. still works like a champ.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 20, 2015, 11:33:10 PM »
I just switched out both DACs with new chips from Mouser ... same results
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 20, 2015, 11:03:10 PM »
Ok, de-soldered, then carefully re-soldered all of the pins that match the preenF405 to the DACs on both sides (all 3 chip sockets) ... Used an oscilloscope to view the preenF405 spi_ck and on both DACs ... The clock signals are solid and appear the same on both sides. The 2.5v pins on the DACs still read 3.99v each ... resistors also read 4.02v still .. so no audio / no real change. I tested continuity after re-solder and the signal is clean on all pins preenF405 to both DACs. I used a different voltmeter this time too :>)
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 18, 2015, 10:46:48 PM »
Will do!
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 18, 2015, 08:34:20 PM »
I ran the round of continuity tests in the green picture. All chime in strong. I checked a couple of times to make sure.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 17, 2015, 10:55:14 PM »
5v test complete. Most points show slightly under 5v .. More like 4.88v ... The op amp shows 4.88 on the 5v pin, and 4v - 4.02v on all but the pin which is ground (continuity is good on that pin back to the top of the 5v regulator)
I'll check the continuity next ... I took a coffee break for this test, so may be a while before results of the other test.
I'll check the continuity next ... I took a coffee break for this test, so may be a while before results of the other test.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 17, 2015, 07:10:39 PM »
I have 2 oscilloscopes, but no probes! I can work on that though. They were out on loan and the probes didn't return.
After work today, I will carefully go through the tests you've outlined and check to see if voltages / values are correct. No worries about it being easy ... i'm patient and I don't mind checking :>)
Thank you for all of your help.
After work today, I will carefully go through the tests you've outlined and check to see if voltages / values are correct. No worries about it being easy ... i'm patient and I don't mind checking :>)
Thank you for all of your help.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 17, 2015, 04:04:09 AM »
Hi Xavier,
Ok, cleaned up and hit all of those audio section solder joints looking for shiny. Took away a lot of solder, checked for voltage (still 4.02v at the 68 ohm resistors / 3.85v on DACs) and removed the op amp and checked for audio (volume all the way up) ... precisely the same results.
Ric
Ok, cleaned up and hit all of those audio section solder joints looking for shiny. Took away a lot of solder, checked for voltage (still 4.02v at the 68 ohm resistors / 3.85v on DACs) and removed the op amp and checked for audio (volume all the way up) ... precisely the same results.
Ric
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 16, 2015, 10:47:22 PM »
Yes, volume is definitely turned up ... the audible "pops" on boot go away when it's down.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 16, 2015, 10:46:27 PM »
I'll try the audio test with the op amp out again .... Then I'll clean up those points in the circle ... I have an iron just for that ... then I'll try the audio test without op amp again.
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preenfm2 and preenfm3 / Re: My first preenFM2 metal case built from kit #1 of 3 .. trouble shooting no audio
« on: September 16, 2015, 10:34:45 PM »
Still reads zero .. have pleasant night Xavier