I have a couple of HGST (Apple branded) 1TB drives. When I put them in the Sabrent EC-UASP enclosure and connect them to a PC, they spin up and work just fine.
The same drives, one at a time, both together, any combination, in the DS-4SSD 4-disk bay will not spin up. If I have another (working) drive in the bay, then the whole bay goes into limbo, no drives spin up.
This appears to be a power-on issue as the drives won't spin at all (never mind getting connected etc).
So far this has happened with only these two Apple labelled HGST drives. Apple labelled Seagate drives and HGST labelled drives also pulled from Apple products, also work just fine.
So the question is this: What is the difference in the power wiring of the DS-4SSD compared to the EC-UASP?
Thanks.
@Alex Kampas The EC-UASP is USB-powered with a SATA-USB chipset and the DS-4SSD takes a separate power adapter and is a SATA-USB chipset with a port multiplier chipset. The latter should be the JMS567 and JMB575 which have different electrical compliance than some of the chipsets used in the EC-UASP, such as the JMS578. The SATA-USB bridge can be verified with USB Device Tree Viewer. This may be a compatibility issue.
No, the DS-4SSD is NOT JMS567+JMB575. It's JMS561U, which is by the way unsuitable for SSDs because it does NOT support TRIM/DISCARD, it does NOT support hot-swap or even hot-plug, and has all kinds of other features like refusing to work in some USB slots while working in others.
By my experience, the "power-on issue" is that it fails to recognise a USB connection, and spins down the drives. Plugging it into another USB port helps sometimes.
@mad-jester I will investigate this, thank you.
Edit: None of our DS-4SSDs were shipped with a JMS561U.
@mad-jester We opened up some units and they were not the JMS561U, despite the ID reflected in some utilities. However, we have requested that new DS-4SSDs be updated to a newer chipset that will not have the problems you list.
OK I have two DS-4SSD to use with M1 macs. a mac mini and an apple studio. First arrived and I couldnt power on the SSDs although the fan worked so there wasn't a power problem. I tried different SSDs in a different configuration - nothing. The suddenly it started working. Maybe a different USB port - who knows. Just got a second one and exactly the same problem. Tried an old macbook pro, nothing - apple studio different ports - nothing. 3x Mac SSD's inside - Push the power button and nothing happens. restarted changed USB cable changed ports - nothing.
@G M It may be a defective unit. We tested it here on a M1 and it worked with the power button pushed and power status light illuminated in addition to fan LED. Verified by checking Disk Utility.
