keves Posted November 28, 2015 Report Share Posted November 28, 2015 (edited) Hello!I'm currently in the process of building the awesome Midibox SEQ using Wilba's front panel PCB from SmashTV's shop. I am using an STM32F core board. I have soldered the following on the front panel PCB:- All diodes- J1 connector- All 5 pin resistor networks- All IC sockets- All pushbuttons- Capacitors I have not soldered ANY of the following:- Resistors- Rotary encoders- LEDs- Anything else I am missing? I have two LCD modules connected to my core board (and they work fine), and the front panel PCB (to J8/9). Pressing any of the buttons does not do anything. Things I have checked:- All diodes are in the right orientation- All ICs are in their sockets in the right orientation (U1-U6 are the 165, U7/8 are 595)- I can see a clock signal on J1 SC pin. I can see VCC and GND. One important mistake that I made: I initially soldered the J1 connector in the wrong orientation (or the flat cable I used is different than the one that's on the photo instructions thread). This resulted in U1 overheating and may have ruined it or anything else. After discovering this awful mistake I used wire patch cables to connect the core module and the PCB so I am fairly certain they are properly connected now (I can see a clock signal on SC, and measure ~5v between VS and VD). Does anyone have an idea of what can be wrong? Here are some theories that I have but not sure if they make sense:- I ruined some or all the ICs - thankfully they are socketed so I will just order a bunch of new ones and try that next week.- I ruined something else - I doubt that because capacitors, switches and diodes are pretty resilient and I can't see reversed connector being an issue- This thing does not work without the LED resistors (I doubt, but maybe I'm wrong? I couldn't find a schema of the board online). I have access to a 2 channel scope so I can look at signals if someone has an idea of what would be worth checking. Many thanks! Edited November 28, 2015 by keves Quote Link to comment Share on other sites More sharing options...
latigid on Posted November 28, 2015 Report Share Posted November 28, 2015 (edited) Something else to check is the orientation of resistor networks, they have a dot which must align with the PCB legend.To test if the chip survived, you could try to swap some around and see if you can get a bit of functionality.Depending on the buttons you ordered, it is still possible to misalign these by 90 degrees. Edited November 28, 2015 by latigid on Quote Link to comment Share on other sites More sharing options...
keves Posted November 28, 2015 Author Report Share Posted November 28, 2015 Thanks for the reply :)I also checked the resistor networks, they are properly placed. I used the buttons SmashTV sends in his parts kit, and they cannot be misaligned. I ordered new chips so I will just try that next week when they arrive. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted November 29, 2015 Report Share Posted November 29, 2015 Had the same problem once - with the 180° rotated cable. I doubt, you ruined your shift registers, mine got very hot and I did not realize it for a few minutes (drinking that coffee was more important! ;-)).I therefore suspect sth else, but I might be wrong, ofc :-).Suspection:Make sure, that Serial IN and Serial OUT (SI/SO) lines are not accidentally swapped. This could still happen, if the cable is built wrong. You can test to swap these lines (nothing bad can happen).A good test is to use a continuity tester / ohm meter to map the silkscreen printouts of J8/J9 with J1 on the SEQ CS. A few other tips:Check for voltages across the CS board. Every IC must be powered with 5V across its supply pins.Enable the SEQ Button test mode in the MIOS Terminal.Insert a few resistors and LEDs (no real need to solder), just add 9 220R Resistors at the center of the board around the center encoder slot and add just one LED above the first GP button - it should light up after booting.Attach your scope with the probe to the serial lines and (and probe gnd to gnd). You should see high-speed pulsed signals on J2 of the CS PCB (it is a serial extension of the inputs from J1 to attach other hardware, like the TPD board). Many greets and good luck!Peter Quote Link to comment Share on other sites More sharing options...
keves Posted November 30, 2015 Author Report Share Posted November 30, 2015 Thank you for the detailed reply!I am embarrassed to say it was SO/SI - can't believe I didn't double check that one! Seems to work now :D :D :DThe ICs indeed seem to have survived even though the did overheat like you mentioned. Oh well, now I'll have a few more of them :)Thanks again, this made my day!!! Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted November 30, 2015 Report Share Posted November 30, 2015 Congrats and enjoy that SEQ V4 - the best hardware sequencer on this planet (R) ;-)Many greets,Peter Quote Link to comment Share on other sites More sharing options...
keves Posted November 30, 2015 Author Report Share Posted November 30, 2015 Super looking forward to have it fully working! Quote Link to comment Share on other sites More sharing options...
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