No boot if sid connected to core.

MIDIbox SID
1

ok. If I have the core and the sid connected, and the 5v connected to the sid, I get no power. if I disconnect the 5v to the sid, the PIC powers up, but LCD remains blank. if I completely disconnect the sid from the core, the pic boots up fine. don’t know what could be happening since the cable I madew to connect the 2 is the same one I always used. I tried the other 3 that I’ve also made, and I get the same result to test if the one cable is bad. all this after spending the day rewiring power and audio from a previous teardown.

???

any ideas?

2

did further checks. if the Vs and Vd lines on J2 of “ANY” SID module are connected to 5v, the whole unit doesn’t power on. I even tried swapping the polarity to see if I had plugged it in backwards by mistake, and it still will not power up.  :-\

??? ??? ??? ??? ??? ??? ???

3

ok. battery to voltmeter almost dead.

think I may see an error.

The Sid boards that I have are

Master: SID_R3

Slaves: SID_R3A

With J1 of the Sid modules and checking the “mbhp_4xsid_c64_psu_optimized.pdf”…

the Modules I have do not have Vs and Vd Marked on the boards.

According to the PDF, It would appear that I have the 12v power connected to Vs.

This tells me that the power could just be dumping straight to the ground.

Do I need to move the wires over to what would be marked as Vd? 

Or does it matter with the version boards that I have considering that there’s a rectifier setting right after J1? ???

I’ll check into it, in the meantime, give me some ideas if you have any.  :-\

4

Um, this sounds pretty weird :wink:

I’d try the following:

  1. Leave the 12V for the SID alone for now (remove it, hide it somewhere)

  2. Remove all ICs

  3. Do voltage check on the core with nothing connected to it

  4. On the SID board is should be fairly ease to see, which of the lines of J2 is Vss (GND) and Vdd (+5V)  - Just trace the pins to the ground plane and the power pin of some IC. Just connect those two lines.

  5. Do voltage check on SID.

  6. Tell us what’s the result :smiley:

5

thanks to the help of smashtv, nILS, and bugfight in the chat, this has been resolved. had a short that was being created by leads poking through the insulation and making contact with the aluminum panel.  :smiley: