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Twin-X

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  2. Help needed again!

    in Testing/Troubleshooting

    Posted

    Hi Jeffry,

    could it be that your multimeter is not working? Which kind of measuring instrument are you using, do you have to calibrate it?

    Because:

      6.7V instead of 5V makes ca. 30% error

      15.6V instead of 12V makes ca. 30% error

      11.6V instead of 9V makes ca. 30% error

    so, you always have an offset of ca. 30%

    Do you have a 7805 and a second PSU?

    Solder the 7805 to the core module and power it from J1, which value do you measure at J2, 5V or 6.7V?

    Best Regards, Thorsten.

    I have a el cheapo multimeter. The battery seems dead almost. I am gonna try it again tomorrow with new battery!

    Pac_c thanks for cheering me up. I will have a good night rest now :D

  3. Help needed again!

    in Testing/Troubleshooting

    Posted

    I removed all chips.

    Could you please try the following: remove all ICs from the core module, connect only the LCD (+backlight!). Then connect the +5/ground output of the PSU circuit to J2 of the core module and measure the voltage. The result should be in the range between 4.5V and 5.5V

    It's 5.17V

    14V: so long the voltage at pin 28 (Vdd) of the SID is less than 12V, the internal audio amplifier won't work correctly, and you won't hear anything. So, your first goal will be to bring this voltage (behind the 7812 of the SID module) to 12V.

    Here the same: remove all ICs from the SID module. A certain load is not required for this test. Connect the ground and +14V output of the PSU circuit to J1 of the SID module and measure the voltage between ground and pin 28 of the SID socket. Which value do you see?

    It's 12.01V

    Measure also the voltage at J1, is it still 11.06V, or higher?

    It's 14.11V

    • the voltage between pin 1 and 2 of the 7809 of the PSU circuit
    • the voltage between pin 2 and 3 of the 7809
    • the voltage before the rectifier of the PSU circuit (note: it's AC, you have to select this at your multimeter)
    • is your PSU from an old C64 or from a C64 II (which contains the 8580 instead of the 6581)

    1. 12.05V

    2. 8.93V

    3. 9.5VAC

    The PSU is from a C64 I i have tried two of them. Both of the PSU same results.

    Cheers,

    Jeffry

  4. Help needed again!

    in Testing/Troubleshooting

    Posted

    Hello all,

    Thank you so much for taking effort in trying to help me out.

    I have had a lot of sid problems since the control unit didn't work.

    So i wish to start from the beginning.

    First issue!

    My optimized psu is not giving the right voltages!

    I get 6.13V on the +5 and 11.06V on the 14VDC connected to ground of the power-led

    What can be broke the regulator?

  5. Help needed again!

    in Testing/Troubleshooting

    Posted

    Ok i am fed up with it. Who wants too look at my quad sid. I will pay for all inexpenses.

    If not then i will sell the unit.

    I have tried everything and despite the help i have recieved nothing helps. I am blaming myself let that be clear.

    Anyway pm me if you want to have a look at it.

  20. Midibox CV & Hz/V

    in Design Concepts

    Posted

    now possible to order as a regular customer too. Though the minimum order price has to be 100 Euro and payment in advance.

    I assume your'e from the Netherlands since in all other coutries you can just order as a normal customer. (at least in brittian and germany it is)

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