Tom2112
Well-known member
The TL;DNR version:
Don't use a cheap power supply for your external RaSCSI/Rasperry Pi combo. The just-good-enough-to-power-up power won't be enough for running the RaSCSI and termination too and it won't have proper termination and you'll spend hours trying to figure out why it doesn't work.
The long version:
I spent almost 1/2 a day trying to figure out why my PowerBook 165 would NOT communicate with my RaSCSI. I won't bore you with all of the nitty gritty details, but suffice to say, had the Pi not been headless, I would have known it wasn't getting enough power. But with it being headless, there isn't an idiot light to tell you. In my case, the Pi (a Pi 3B+) had enough power to boot and run the RaSCSI scripts, connect to my wifi, and make it look like it was working just fine. But the Mac it was connected to just wouldn't see it. Since the PowerBook was new to me, the RaSCSI was new, as was my newly purchased HDI-30 to DB-25 adapter, I went through a lot of fruitless troubleshooting, until finally giving up and pulling out a known-working Mac SE and start troubleshooting there. Also it helped that the SE had files/tools on it I could use to help troubleshoot, where the PowerBook was an island to itself. It was on the SE that SCSI Probe 4.3 finally told me that the SCSI bus wasn't terminated! (Thank you SCSI Probe author! You're a genius, and I wish I could buy you a beer.) Other tools I used didn't tell me diddly (I'm looking at you LIDO). I was beginning to think the RaSCSI was bad. But once I had a good way to see if it was terminated or not, I found that the switches on the RaSCSI weren't doing anything... which didn't make sense. Finally I hooked the Pi up to a monitor (I had installed the desktop version of the OS on this particular one) and immediately saw its low power indicator (lightning bolt) in the corner of the display. Once I grabbed a better quality power supply (I used a good USB power bank), the whole thing worked exactly as it was supposed to work.
I need to wire it up with the old power supply and check the amperages with my meter to see at what amps it creates a problem. The too-low-power PSU was labelled at 2.1 amps, but I don't know what it was actually putting out. The power bank I used says it only outputs 2.1 amps at 5v, so...? I'm betting the cheap Chinesium PSU is literally over-rated.
Don't use a cheap power supply for your external RaSCSI/Rasperry Pi combo. The just-good-enough-to-power-up power won't be enough for running the RaSCSI and termination too and it won't have proper termination and you'll spend hours trying to figure out why it doesn't work.
The long version:
I spent almost 1/2 a day trying to figure out why my PowerBook 165 would NOT communicate with my RaSCSI. I won't bore you with all of the nitty gritty details, but suffice to say, had the Pi not been headless, I would have known it wasn't getting enough power. But with it being headless, there isn't an idiot light to tell you. In my case, the Pi (a Pi 3B+) had enough power to boot and run the RaSCSI scripts, connect to my wifi, and make it look like it was working just fine. But the Mac it was connected to just wouldn't see it. Since the PowerBook was new to me, the RaSCSI was new, as was my newly purchased HDI-30 to DB-25 adapter, I went through a lot of fruitless troubleshooting, until finally giving up and pulling out a known-working Mac SE and start troubleshooting there. Also it helped that the SE had files/tools on it I could use to help troubleshoot, where the PowerBook was an island to itself. It was on the SE that SCSI Probe 4.3 finally told me that the SCSI bus wasn't terminated! (Thank you SCSI Probe author! You're a genius, and I wish I could buy you a beer.) Other tools I used didn't tell me diddly (I'm looking at you LIDO). I was beginning to think the RaSCSI was bad. But once I had a good way to see if it was terminated or not, I found that the switches on the RaSCSI weren't doing anything... which didn't make sense. Finally I hooked the Pi up to a monitor (I had installed the desktop version of the OS on this particular one) and immediately saw its low power indicator (lightning bolt) in the corner of the display. Once I grabbed a better quality power supply (I used a good USB power bank), the whole thing worked exactly as it was supposed to work.
I need to wire it up with the old power supply and check the amperages with my meter to see at what amps it creates a problem. The too-low-power PSU was labelled at 2.1 amps, but I don't know what it was actually putting out. The power bank I used says it only outputs 2.1 amps at 5v, so...? I'm betting the cheap Chinesium PSU is literally over-rated.