SCSI2SD power from micro-USB

[Eamoe]

I have a SCSI2SD in my Amiga 2000. I’ve been setting it up with a micro-USB cable taking juice from my cell phone charger wall wart. The goal has always been to tap 5V from a floppy power cable internally when everthing would be set up. Which I did — but it doesn’t work that way. The SCSI2SD seems underpowered when using internal voltage source like this. It is weird because my phone will fast-charge from this custom-installed cable (that is, using the A2000 PSU 5V rail).

Any ideas as to why it does provides with power but still won’t make the SCSI2SD work?

[idrougge]

Doesn’t you SCSI2SD have a hard drive/floppy power connector?

[Eamoe]

It does. The large molex HD connector. But it doesn’t work when I use just this. Actually the SCSI2SD won’t work if I only use one connector, micro-USB or molex. Both need to be plugged in. In know it sounds weird, but it’s just that.

[Jope]

The micro usb shouldn't be used when it is being used for SCSI. Sounds very strange that yours won't run off the power connector.

[FOL]

Originally Posted by Jope

The micro usb shouldn't be used when it is being used for SCSI. Sounds very strange that yours won't run off the power connector.

Unless its been shorted and blown molex power side protection circuit.
I have never ever seen one of these just go faulty. They are always installed incorrectly or shorted out.

Originally Posted by Eamoe

It does. The large molex HD connector. But it doesn’t work when I use just this. Actually the SCSI2SD won’t work if I only use one connector, micro-USB or molex. Both need to be plugged in. In know it sounds weird, but it’s just that.

You should have 5v on Molex connector. Are you getting that? Id check voltage also on fuses, see if you have voltage there.

[jrobbins70]

I was able to power my SCSI2SD using the USB on it. I had to buy an adapter that went from molex to USB:

https://www.amazon.ca/gp/product/B082FB2WK6/

My power connector on the card stopped working too, so I'm left with using power from the SCSI cable or the USB connector. I picked USB.

J

[Eamoe]

Originally Posted by FOL

Unless its been shorted and blown molex power side protection circuit.

Could be that. Although I can't see how I'd have blown it.

Originally Posted by FOL

You should have 5v on Molex connector. Are you getting that? Id check voltage also on fuses, see if you have voltage there.

I am getting 5.1V on the 5V side of the Molex. And then it normally couldn't be that connector that blew the Molex power circuit, because it is keyed, i.e. I couldn't have fed it 12V by mistake. Did not check the fuse though. I'd have to find it on the SCSI2SD.

Originally Posted by jrobbins70

I had to buy an adapter that went from molex to USB:

https://www.amazon.ca/gp/product/B082FB2WK6/

Wow I hadn't thought anyone sold adapters like these... I had to mod a Molex connector to make my own.

Anyway, I made some further, careful testing. Powering from the Molex connector only does not work at all. I now power the SCSI2SD using my USB modded cable alone. I actually works. The thing is, it doesn't work on hard boot. I have to soft-reset (Ctrl-Amiga-Amiga) the machine once after hard boot for the SCSI2SD to be recognized. It looks like there is a "lag" in power distribution coming from the A2000 internal PSU. When powered with a wall wart, it works every time, because the SCSI2SD is powered even before the Amiga powers up. But from internal power, it won't work on initial power-up. It'll stay black for a little while, and then go to Guru, error code 8000 000B.

I had completely recapped this PSU when I found the Amiga, but I used the same values (capacitance and voltage ratings), and only Nichicon-branded stuff. So I don't see this being a factor.

Anyway, it works (although still not from the Molex connector), but isn't there some delay setting I could use so the controller "waits" a second or two before "sniffing" the SCSI line?