USB and DMA problem--OT

[Sciascia]

Of course it's off topic--I think that's all I post anymore Anyway I have exhausted all of my resources, internet, tech support, yelling at the PC and calling it names to no avail. I was getting ready to go to bed and I always take a look here so that I can spend another hour or two wading through the posts and I thought, "these guys have had every problem known to man, I bet someone knows" Ok enough buttering...

Here is the situation. I have a Tyan Tsunami AT 1830s MB. It is a slot 1 440BX board with AGP, 4 PCI, 3 ISA and 1 shared slot. I never messed with USB devices too much because I had problems with them. Apparently it wasn't the devices but the MB itself or config. If I have DMA enabled on my Primary IDE controller (WinME or Win98SE) it loses connection with my USB hub. It is not the hub since it works great on my laptop. I have a USB Ethernet adapter that after I lambasted Linksys for not working on my desktop works great on my laptop. (Sorry Linksys--it is one of the best $50 that I ever spent). Here is my sytem config.

IRQ 0 System timer OK
IRQ 1 Standard 101/102-Key or Microsoft Natural Keyboard OK
IRQ 2 Programmable interrupt controller OK
IRQ 4 Communications Port (COM1) OK
IRQ 5 IRQ Holder for PCI Steering OK
IRQ 5 Vortex AU8830 Multifunction PCI Platform OK
IRQ 5 Vortex AU8830 PCI Audio OK
IRQ 6 Standard Floppy Disk Controller OK
IRQ 7 EPSON Printer Port (LPT1) OK
IRQ 8 System CMOS/real time clock OK
IRQ 9 IRQ Holder for PCI Steering OK
IRQ 9 Intel 82371AB/EB PCI to USB Universal Host Controller OK
IRQ 9 3Com EtherLink XL 10/100 PCI NIC (3C905-TX) OK
IRQ 10 IRQ Holder for PCI Steering OK
IRQ 10 Matrox Marvel G400 AGP - English OK
IRQ 11 IRQ Holder for PCI Steering OK
IRQ 11 Win9x-ME Promise FastTrak100 (tm) Controller OK
IRQ 13 Numeric data processor OK
IRQ 14 Intel 82371AB/EB PCI Bus Master IDE Controller OK
IRQ 14 Primary IDE controller (dual fifo) OK
IRQ 15 Intel 82371AB/EB PCI Bus Master IDE Controller OK
IRQ 15 Secondary IDE controller (dual fifo) OK


I have tried it with no network card or RAID installed--no difference. I am convinced that it is a PCI BusMastering or bandwidth issue. And the no hub situation isn't even good because my brand new Casio QV3000 doesn't like the USB port nor do my game controllers. If the Hub is connected they atleast show up before the HD kicks in and screws up the install. I also checked for ESD and voltage problems. It is rock solid 5+/- .03V with/without HD access.

Any ideas?
Sciascia

[wkulecz]

Is your hub powered or unpowered? I know quite a few BX motherboard USB implimentations can't supply the USB spec'd power to external devices. I've seen claims that "replacing a resistor" fixes the problem.

I think there are some buggy revisions of the Intel 82371AB/EB PCI to USB as this is what W2K reports on my Dell Notebook and I cannout output DV from a PCMCIA 1394 card and external 1394 drive back to the camcorder unless all USB devices are unplugged.

Sorry for no real help, but about the only unpowered USB device my 440BX ASUS P2B-D can drive is a SanDisk compact flash reader. I have no troubles with the Hauppauge WinTV USB, but it has its own powersupply.

--wally.

[Sciascia]

I guess that I should have mentioned that it is a powered hub. What resistor are you referring to or do you have a link?

Thanks

[Sciascia]

I fond something interesting....the southbridge controller is responsible for the USB and IDE controller (as well as ISA). So I believe that I found a link in the problem. Of course what to do is a good question.

[Greebe]

The resistor is there for current limiting... for example, my M$ Internet Keyboard Pro has 2 USB ports on it and spec'd at =<100ma of current (Low power USB devices only will work). So to allow it to work with higher powered devies I would need to change that reststor. Now I'm sometimes lazy and thus haven't taken the time to figure out which (or even bothered to search the net for someone who already has), but that's besides the point. There isn't any specific place this critter to be located, so determining what your's is I'd have to see it or like above do a search and hope another already has figured it out.

Either way this is mute, if you are using a powered hub that resistor is not part of the problem, for the hub will supply a high current USB device by itself.

[Sciascia]

I caved in. I was looking at new motherboards, but didn't find anything that made me happy. Too many questions about AMD and VIA chips to convince me. I just bought a $25 USB controller card and it works great now. Tyan tech support sucks. All they sent to me was a pitiful lin kto their useless FAQ page. It appears that others have had the same problem. I am really irritated because I asked them long ago and several times about this problem. Each response that wasn't automated was "it's the drivers for the device". What a poor excuse for customer service. That is the last money that they will get out of me.

On a positive note I bought a cheapo game pad a while back form Interact(???) and asked for help from them. At that point I wasn't sure about the cause. I got a fast response and even after I told them it wasn't their device they asked for my system info to try to help me out. Another gold star goes out to Belkin. They were fast and helpful even though they didn't resolve the problem. I apperciate the support of both these companies and their devices work great.

[Sciascia]

OK, I couldn't let it rest. It was bugging me to death that I couldn't fix this. I found an old message in the Tyan newsgroup that had the fix. Turns out that it is a voltage divider circuit that had a wrong value resistor. Unfortunately it is a tiny surface mount (when I say tiny, I mean tiny) that either needs to be replaced or have another resistor placed in parallel to correct the voltage problem. It is a 470k 1/8 watt resistor placed in parallel with R136 (located near the USB headers on the MB near a large component named "F2"). There is a circuit run going to F2 so I soldered one leg to it. Threw it in there and it works great, took about 45 minutes for the whole deal. It requires a steady hand and good to above averge soldering skills.

A PCI USB controller card also works fine...for the timid.
First time these ports have worked in over 2 years!!

Thanks Greebe for opinting me in the right direction. It apparently did have some effect with the self powered hub.

Got some more life out of this otherwise great board that just happens to have piss poor tech support.

Sciascia

[Sciascia]

OK here is the link. Hopefully it isn't too bad (first time building a webpage). Hope it helps someone else out there holding on to these boards.

http://www.geocities.com/ashasha3/