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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Michele31415 on September 18, 2021, 07:39:54 PM
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I got a floppy power cable from AmigaKit to connect my SCSI2SD v. 5.2 directly to my GVP HC+8 controller card. Unfortunately, the connectors on the cable were keyed and didn't fit on either the SCSI2SD or the GVP so I had to cut off the keys. Now I have two connectors that can go on either way.
GVP was nice enough to print on the board which pin was 5 v. and which was 12 but the SCSI2SD is unlabeled. So could someone please tell me which end on the SCSI2SD is 5 v.? The one nearest the SCSI cable or the one nearest the edge of the board? I've looked everywhere and can't find this.
Going by the connector I'm currently using (one of the pigtails from the Amiga's power supply whose key does fit only one way), I'm guessing that 5 V. is the end nearest the SCSI connector since that wire is red and red should be 5 v. But I'd appreciate confirmation before I let the magic smoke out of my SCSI2SD.
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Hello Michele31415,
As I don't have 1 yet, best advice is that Common Ground is ALWAYS the biggest trace that goes all over and around on the board the 5 and 12 volt pins are likely short and only go to devices for a short distance and tend to jump around, they are in naturally very skinny. Typically at every chip there is a "trash" filter at the head of each chips power in, a .01 uf cap is used mostly for this.
Chris
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Well now I'm really confused. I got out my trusty ohmmeter and measured to fuse F202 which according to the schematic should be connected directly to the Berg connector input. I got continuity to the outside pin (closest to the edge of the board) and none on the innermost pin (closest to the SCSI connector). This would suggest that +5 V is on the outside pin. But the Amiga floppy connector I've been using only goes on one way and that way puts the yellow wire on the outside, and yellow is +12 V! But it's been working fine. ???
Could someone with a SCSI2SD v. 5.2 please tell me what colors go where on their Berg connector?
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Having heard nothing back I did some further poking around and found this image here https://pcweenies.com/2020/02/27/restoring-a-mac-se-fdhd-dead-drives-no-more/ that pretty conclusively indicates that the red wire goes nearest the card edge. I wonder why I didn't blow up my board by powering it from the Amiga's floppy connector (which definitely only fits with the yellow wire on the card edge side).
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Would have replied sooner if I saw this thread.
Yes, 5v is on outside edge of card. I too, has simular issue on our test setup. So I soldered a floppy molex to main board. so I can use either 3.5" drives and scsi2sd adapters.
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Thanks for replying anyway. Yes, one can never have too many floppy connectors. Between DF0, SCSI2SD, and Goteks, there's never enough to go around. And a hint to the SCSI2SD designers - would it kill you to silkscreen the phrase "+5V" at the appropriate spot on the board?