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Thread: Commodore 1571.. red and green led always on and motor to check reset line?

  1. #1

    Default Commodore 1571.. red and green led always on and motor to check reset line?

    I have two 1571, both with the same issue. Power on and red led and green are always on, and the motor runs continuosly. Check with different power supply and measure it, the 5v and 12v is correct.
    With another 1571 ICs parts, change the u1, u2, u6, u8, u11, u12, u14, u15 and u16 and the same problem. I have replaced too the electrolitic capacitors.
    I'm suspect the reset line/clock, any help? Another IC to change and test?
    Thanks in advance!

  2. #2


    What are each drive's numbers switches set to be (up down)? I assume they're not both the same, or you'll have issues caused by drive assignment conflict. Do you have the same exact issues whether you have one drive plugged in or only two? Have you tried the drives on a different machine?

    What happens when you're in C128 mode (assuming you have a C12 and you enter and run the command: ?ds$ - this command's output will tell you if the processor board of the disk drive is OK or not. The response you want will be something like: "73, cbm dos v. 2.x"
    @ BillDeg:
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  3. #3


    Hi billdeg...
    Tested separately, the same exact issue in c64 and c128 in c64 mode. When i try with load"$",8 the computer is freezed in "Searching for"

  4. #4


    Tested separately in a C64 and 128 in C64 mode. When i try to get directory with LOAD"$",8 freeze the computers. Stay in "Searching for" and lockup computers.

  5. #5


    from 128 mode what happens when you

    1. attach the computer to the drive. powered off. Verify drive switches are set to = 8.
    2. power on the drive - what is the drive light initialization blink pattern? What is the drive doing while it waits.
    3. power on the computer in 128 mode - what is the drive light initialization blink pattern, same as #2?
    4. run the command


    - what text prints to the screen?

    @ BillDeg:
    Twitter: @billdeg
    Youtube: @billdeg
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  6. #6


    Hi BillDeg, thanks for your reply..

    I found a strange situation. One of the 1571, start ok now. How? A bit of luck. Grounding the pin n22 of u6 (hd61j215p), N/C refer in IC 1571 technical manual info, the drive start correct, green light shut off and motor stop after a few seconds.
    If i cut that pin from board, the drive always start with red and green led on and motor runs and never stop. The bad news with this drive, FILE NOT FOUND error and 74 drive not ready. Tested with 2 differents mechanical parts
    in working conditions in another two 1571s.
    The other 1571, still with same sympton and answering your questions:

    1. Switches are correctly set to n8.
    2. red and green lights always on, start motor and never stop.
    3. If i power on the 128 with drive on, the 128 show screen and hang/freeze the computer. No cursor to write.
    If i power on first the 128 and then the drive, no way to access the drive, the same with PRINT DS$. Hang/freeze the 128 and need to turn off.

    Image attached, look pin n22 of u6:

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