iMac Pro review
I have an irrititating problem with two of my systems.
I have a usb hub and a usb switch so that several pcs can share several devices such as mouse, keyboard, scanner, zip drive and compact flash reader.
Two pcs are quite happy to boot into W2000 with the hub active but two other pcs hang early in the boot up process, also w2000.
The solution is to boot up first then make the hub active via the switch.
One problem pc has a jetway motherboard, one has a gigabyte. Similar motherboards in other pcs boot perfectly.
I also have a ps2 mouse and keyboard attached to all machines via a kvm switch.
Enabling/Disabling USB Keyboard/Mouse in bios has been tried but does not help and even when disabled my usb keyboard and mouse still work!
I know I have a complex setup but I would welcome any advice.
yes, the hub is powered, belkin brand, a very reputable type.
if it didn't work with any pcs i could accpt it but it works with 2 out of 4 and as far as i can tell all 4 pcs are set up the same
Wild guess - - Maybe you need to update the motherboard chipset driver(s)
the most up to date bios has been flashed
Not BIOS, Chipset drivers.
What are we considering here? USB 1.1, USB 2.0 or a mixture of both?
1.1 hub and devices although the motherboards and onboard usb sockets are 2.0 compatible
Sorry Mike, but it would help if I knew a bit more. I assume the switch is a 4x1 and you have the hub connected to the single upstream usb port and the devices are connected to the hub.
Is the switch USB 1.1 also and does it have its own mains power adapter?
Do all the 4 switch/PC cables plug into USB 2.0 ports?
What make are the chipsets on the failing motherboards? VIA? and how old are the motherboards?
It may be that the USB controllers are slow to warm up up or the power supply (PSU) in the offending PCs are a bit 'weak' in that they are not providing sufficient power to the USB controllers at bootup due to the heavy drain on the 5Volt supply at that time.
What is not often recognised is the fact that USB controllers and hubs do not supply a full 500mA or bandwidth immediately - there is a staged process in providing both - hence the number of problems with USB devices after a cold start.
Of course it may be a lot simpler than that!
you are absolutely right about the configuration
pcs to switch then uplink to 4 port hub.
the hub is usb 1.1 and the switch claims to be 1.1 and 2.0 compatible
the switch is unpowered, made by belkin and matches the hub which is powered.
the mobo chipsets are via kt333 and kt400a on the ones that don't work and via kt133/vt8363 and kt400 on the ones that do work.
the failing motherboards include a brand new gigabyte Ga7VAXP Ultra A and a Jetway 333DA, the working ones are a Jetway 663AS and an old Pentium II
both pcs that do work plug into usb 1.1 ports and of the 2 that do not work 1 is 1.1 and one is 2.0
the failing pcs have a 350W psu in one case and a 550W on the other whereas the working ones have 250W and 350W.
i will try and progress tomorrow by connecting just the hub and then just switch and hub then one device at a time.
thanks for your advice and expertise
This thread is now locked and can not be replied to.