Weird USB issues

[ratdude747]

My main rig is haing the following USB issues:

- The internal card reader will stall/freeze after a while

- The USB hubs on the monitors I installed cause a no-POST when connected to the Onboard USB

The USB is at least partially fed off the 5Vsb (as the card reader LED is always on, even when powered off). When running, the measured VCC at the port is 4.84V

My system is based off a Tyan K8WE... with a 600W seasonic PSU (kinda on the edge of it's output specs, I'm drawing maybe 550W or so)... I haven't recapped it.. while it's full of Su'scons I haven't had any other issues...

Any other suggestions on where to look for the problem?

[ratdude747]

Re: Weird USB issues

Bump. Is 4.8V an acceptable USB voltage?

[goontron]

Re: Weird USB issues

Bump. Is 4.8V an acceptable USB voltage?

most USB devices will run on as low as 3v. with the exception of those USB to 2.5 HDD converters that like to kill drives

[mariushm]

Re: Weird USB issues

Yes, it's within the limits according to standards. At the connector... the cable itself may have some voltage drop as well.

[momaka]

Re: Weird USB issues

... with a 600W seasonic PSU (kinda on the edge of it's output specs, I'm drawing maybe 550W or so)...

I doubt that. Get yourself a kill-a-watt meter and check wall power usage. I bet even that is not 550W at peak usage.

I haven't recapped it.. while it's full of Su'scons I haven't had any other issues...

Any other suggestions on where to look for the problem?

Some motherboards power the USB ports from the 5VSB rail. Check 5VSB caps in PSU or replace if in doubt.

4.85V on USB seems a little lower than what I am used to seeing, but it should still be okay.

[ratdude747]

Re: Weird USB issues

I doubt that. Get yourself a kill-a-watt meter and check wall power usage. I bet even that is not 550W at peak usage.

I know you'll disagree, but running a PSU load calculator, it was just around 550W. Given the PSU's heat output under load, I'd believe it.

Some motherboards power the USB ports from the 5VSB rail. Check 5VSB caps in PSU or replace if in doubt.

4.85V on USB seems a little lower than what I am used to seeing, but it should still be okay.

The PSU could use a recap... full of su'scons, probably dried out. I thought 4.85 seemed low too (hence why I posted it).

[mariushm]

Re: Weird USB issues

screw psu calculators, i'll have to agree with momaka.

Get a kill-a-watt, they're cheap. I'll bet it hovers around 250-300 watts. (or get a multimeter/clampmeter and measure current but be careful )

[ratdude747]

Re: Weird USB issues

I'm sure it draws more than that... there was a 400W psu requirement for the board... Add twin GPU's...

[mariushm]

Re: Weird USB issues

The requirement for 400w is to make sure the power supply can provide enough amps on 12v. Saving stupid people from using those 20$ crap power supplies on newegg.

mb eats 30-50 watts, each cpu eats about 60-90w, ram about 3 watts each module, hdd about 6-10w each...

As for twin gpu's... the gpu will pull a maximum 60w from slot , 75w from each pci express 6pin connector and rarely the two gpus will both run at maximum and when you run games you won't have both cpus at 100% etc etc

[ratdude747]

Re: Weird USB issues

Whatever. Given that I've gotten one of the two USB hubs to work today, my guess is an LCD issue... I've never torn them down... me thinks at least one has cap issues that are causing that LCD's hub to act goofy. FWIW my LCD's are Dell Ultrasharp 1801FP's.

[momaka]

Re: Weird USB issues

The hubs in the LCD are likely powered by the LCD monitor's PSU and not by the PC. So it probably wouldn't hurt to crack open those 1801FP's either.

[ratdude747]

Re: Weird USB issues

The hubs in the LCD are likely powered by the LCD monitor's PSU and not by the PC. So it probably wouldn't hurt to crack open those 1801FP's either.

That's what I meant...

[ratdude747]

Re: Weird USB issues

opened it up, broke a cable. damn my luck.

The PSU board has a bunch of capxons, not bulged. Will replace anyway.

Yup. Dead. Ripped a flat flex. I can't get a replacement, so I'll have to blow $25 on another 1801FP the next time I'm up north... in the mean time I have a similar 1703fps that is mixmatched but I'd take it over 1 monitor (or two fixed VGA LCD's).

In the mean time, at least I have the caps to order...

[momaka]

Re: Weird USB issues

Is it between the video/logic board and t-con or t-con and panel? If the former, you could just solder extremely thin cables from the video/logic board to the t-con... if you have a steady hand and the nerves, that is. (I don't have the latter).

[ratdude747]

Re: Weird USB issues

Is it between the video/logic board and t-con or t-con and panel? If the former, you could just solder extremely thin cables from the video/logic board to the t-con... if you have a steady hand and the nerves, that is. (I don't have the latter).

Nope. A long thin one between the button/LED board and the logic board... yeah, I could solder it... but I have my reasons for not (not a lot of clearance, etc.)

If a new LCD were more pricey... but at $25 a pop, I'll grab yet another one, and keep this one for parts...

[momaka]

Re: Weird USB issues

Nope. A long thin one between the button/LED board and the logic board...

Aw, cmon, then. That's an easy one! Probably no more than 10 wires total there, if even that many. With some 28 to 30 AWG wire, you can have it running in as little as 30 minutes.

[ratdude747]

Re: Weird USB issues

Aw, cmon, then. That's an easy one! Probably no more than 10 wires total there, if even that many. With some 28 to 30 AWG wire, you can have it running in as little as 30 minutes.

maybe use old 80 pin wire if i have a long enough bit? the only con is is I no longer have a bezel connector... i'll have to clip and unclip the board.

[ratdude747]

Re: Weird USB issues

having gone in, it looks a bit too fine of a pitch to solder by hand in my basement... if I HAD to I would, but it looks tight. much finer than 80pin wire, that is (like twice as tightly cramped)

I may try it for laughs later but for now I'll leave it.

[Pentium4]

Re: Weird USB issues

I have the same exact PSU as you, and I recapped it. Let me know if you want a list of the caps used and I can send the specs to you. It's well designed but, the fan spins insanely slow which doesn't help those Su'scons at all!

[ratdude747]

Re: Weird USB issues

I have the same exact PSU as you, and I recapped it. Let me know if you want a list of the caps used and I can send the specs to you. It's well designed but, the fan spins insanely slow which doesn't help those Su'scons at all!

Iirc I have the list but since you actually did it, send it.