Usual causes of inoperative USB ports?

[berniedd]

Just like the title says. All 4 of the rear USB ports in my 5 year old desktop are dead/malfunctioning/intermittent. Yes, they are enabled in BIOS. At first I thought bad OS, so I tried a clean install of Ubuntu and later on, reinstalled win XP, but none of the ports came back to life. Everything else works in both OS installs. Bad caps in and around the USB ports even though they look OK visually?

[pentium]

Re: Usual causes of inoperative USB ports?

You sure the connectors themselves are okay? I have seen quite a few mashed up USB ports in my time from stuff fralling off desks to small objects lodging in the port.

[washu]

Re: Usual causes of inoperative USB ports?

ICH5 southbridge? Some versions have insufficient ESD protection and can die easily.

[Scenic]

Re: Usual causes of inoperative USB ports?

most of the time when i found dead USB ports on the back and they weren't mashed up, the fuse blew.

happens quite a lot when ppl use external 2.5" Harddrives or other power hungry equipment without the additional powersupply.
or overloaded cheapo USB Hubs without protection.

if the front USB ports are dead it can also mean the connector on the board was plugged in the wrong way around..

[delaware74b]

Re: Usual causes of inoperative USB ports?

I had a customer's computer (HP/Compaq Evo D510 SFF) start doing the same thing. I opened the computer and it was full of popped caps. This model is almost as bad as Dell's SFF for heat build-up. Since your system is 5-years old, I'd check all caps on the mobo before doing anything else. If you find 1 bad cap, replace all of them.

[berniedd]

Re: Usual causes of inoperative USB ports?

I had a customer's computer (HP/Compaq Evo D510 SFF) start doing the same thing. I opened the computer and it was full of popped caps. This model is almost as bad as Dell's SFF for heat build-up. Since your system is 5-years old, I'd check all caps on the mobo before doing anything else. If you find 1 bad cap, replace all of them.

Well, I guess the big caps are the cause, even though they look OK and none are bulged or leaking. Today the computer would hang just after the POST, before it detects the hard drive and CDROM part. I reset the BIOS but it didn't help.

[delaware74b]

Re: Usual causes of inoperative USB ports?

What brand/series caps are on your mobo? Posting your computer system specs can help us in guiding your to fixing your system.

[berniedd]

Re: Usual causes of inoperative USB ports?

It's a Socket 754 ECS K8M88-M2 mobo. Sempron 2600+ processor. North Bridge: VIAK8M800. South Bridge: VIA VT8237

All of the big capacitors are OSTs. None are bulging/leaking but I'm betting they are the problem. There are no beep codes on powering up.

[PCBONEZ]

Re: Usual causes of inoperative USB ports?

OST are famous for going bad with no bloating.

[larrymoencurly]

Re: Usual causes of inoperative USB ports?

In the case of my NEC USB card, one port quit working because the LM3526 chip blew. Ironically, that chip's job is to protect the USB ports:

[ant3202]

Re: Usual causes of inoperative USB ports?

fuse blown
static damages
usb port corrosion (due to cheap parts in casing) causing shorts / bad contact.
capacitor problems
shorts in casing

power supply (most overlooked components)

[kaniki]

Re: Usual causes of inoperative USB ports?

you forgot to add, using too many devices that draw too much power/data that does not blow anything, but knocks the connection for too much requirements and not enough sources. I have seen times where someone will have an AIO printer and try to use it with something like a camera on the same hub. Every time that they tried using both at the same time, they would both get kicked off until they rebooted the PC, then everything would work fine until they tried using both at the same time again.

[berniedd]

Re: Usual causes of inoperative USB ports?

Thanks, everybody. The PSU has been changed but to no avail. There are no devices plugged into any USB ports. I'm going to change the caps, maybe I can still resurrect this mobo yet.