Ideas to finish the job.
  • Hi Olivier , I have problems with the cards and I need ideas where to look for defects. – Start from a control board, assembled has always worked, both with a filter with a filter that cem3379 ssm2044. After a long time the power back and this is the result: Photo 1. The card does not play. Where should I look for the problem? – Second control board, assemble the card without display, position the display to see the parameters but not the balance. The shuthy sounds, balance the display is not playing right now and this is the image: photo2 SMR4 with a card, with photo 3 SSM2044. There is the RN1, badly welded removing it broke. – The filter ssm2044 I adjusted the resonance, the trimmer gave no results and I have continued to tighten, now is not working resonance. He broke the trimmer. – Filter SMR4, I used a newly assembled transformer is not stabilized, now the measurement points are marked green -1.60 V. I already changed IC2: 7905. – I’m using a closed aluminum case, the probed-1 in need of ventilation to cool? – Last question, where can I find cables for prototype.

    Thanks

    Photo 1.JPG
    2077 x 1384 - 875K
    Photo 2SMR4.JPG
    2373 x 1582 - 893K
    Photo 3 SSM2044 board.JPG
    2374 x 1582 - 841K
  • Did you use GoogleTranslate? I can’t make much sense of most of your post….

  • Photo 2 and 3 look like the same problem i had. I fried the 165 on the digital board. This happens easilly if you put the boards toghether to test them without the case and spacers. The regulators shorted to the resistor network on the digital board. You probably have to replace the 165. Its the IC above led 7 and 8.

  • Regarding the first control board, the problem could be with the MCU (ATMega644P) chip – could explain why the LED pattern is not normal and why the LCD receives garbage. Check also the quartz and the nearby capacitors.

    The two other units look stuck in bootloader mode. The culprit might be the 74hc165, but since you mention something about the resistor network this could be the problem too. There needs to be a +5V voltage on the pin11 of the 74hc165 – switch not pressed and pulled-up to +5V through the resistor network ; if not, the MCU will think that the switches are pressed and boot into firmware update mode.

    If you broke the SSM2044 board resonance trimmer and this causes resonance, it’s pretty obvious that this is the part to replace.

    For your power supply problems on the SMR4, follow this. In particular, please post the 6 voltages at the pins of the regulators, and check that you have not swapped them.

    Your case should better have ventholes since the regulators can get quick warm. If this is not possible, you can try using a power supply which generates only 7.5V to minimize the power dissipated at the regulators.

    You can find jumper wires here

  • Thanks to all, the search begins.
    Unimoog.