Plugging in a scanner disables a USB hub, but not USB ports direct to the motherboard

Here’s a conundrum for USB experts… I have a Fujitsu ScanSnap S1500. This is a truly awesome device for slimming down one’s file cabinet. However, for the past year or so it wreaks havoc on the rest of my USB life. I thought it might be my feeble 4.5-year-old desktop but the behavior is even worse with the latest custom-built PC. With the old PC, powering up the scanner (connected via USB 2.0) would disable any USB devices connected via a hub. I replaced the hub with a (powered) plugable 3.0 hub. Same issues. Unplugging the scanner restored normal USB behavior for both hub-connected and directly connected devices.

With the new PC the scanner can coexist happily with the direct-to-the-motherboard ports, as before. But connecting the powered scanner actually seems to have destroyed the plugable hub. Even with the scanner unpowered and unplugged, there is no way to useĀ a USB device connected through the hub and the LED lights on the front of the hub to show connectivity will not illuminate.

I haven’t tried the scanner with a different USB cable so I am not sure if this is simply a cable issue. Could the scanner be establishing its own ground for the USB and draining crazy amounts of power out of the hub back into the PC and from there up into the scanner?

[If the answer is “throw out your 5-year-old scanner” then that leaves the question of whether to buy the WiFi replacement (ScanSnap iX500) or the Fujitsu Fi-7160, which comes with “PaperStream” software that is allegedly optimized for my kind of business use. I was never very happy with the ScanSnap software, which can’t, for example, remember the last folder that was a target for scanned files. Has anyone used Paperstream?]

Philip Greenspun’s Weblog

Leave a Reply

Your email address will not be published. Required fields are marked *