Help! HDD little red light stays on!
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From: Paul on 11 Dec 2009 12:04 Jeff Strickland wrote: > "JD" <No.Reply(a)Sorry.com> wrote in message > news:4b220f72$0$2535$da0feed9(a)news.zen.co.uk... >> Peter Jason wrote: >>> Why? >>> >>> Please help, P >> Hi there >> >> As Jeff and Paul say the drive may be in use if you built it yourself >> connecting the power button to the IO panel you may have put the "PWR >> Switch" wires in the wrong way round which will cause the light to come on >> when the drive is NOT in use and off when it is. >> >> JD > > > While is certainly possible that the lights are switched, if it wasw true > that they were switched, then the Power light should be blinking to indicate > that the HDD is being read. > > The HDD light is supposed to blink on a random schedule as data is being > read, if the light is on continuously then something is making a call to the > HDD causing it to read data all of the time. If the HDD lighth is on steady > and the Power light is blinking, then my money is on the connectors being > switched. > > If the connectors are switched and the machine is Home Built, maybe one > should give consideration to not building any more computers. > There are a couple ways for the LED signal to be created. You could use the status signal right off the IDE ribbon cable (with appropriate buffering). Or, the status signal could be coming from the Southbridge itself, partially under software control. In the case of my LED, which turns on steady while my screensaver is running, I suspect the LED state is being affected by something the driver is doing. And I've tested it, by moving the mouse (to get rid of the screensaver), then double clicking a disk icon to get some hard drive activity. The LED actually blinks off, then comes back on, as if an XOR gate is present in the circuit and the activity state of the LED has been changed (normally ON, blink OFF). Roughly ten seconds after the screen saver has stopped, the LED goes out, and returns to blinking on in response disk activity. So my problem is related to something involving "driver" / "power management state" / "perhaps Southbridge". We really need a more detailed description of what the OP's LED is doing, to decide what it is. If the motherboard has a manual, with PANEL pinout and named signals, it may be possible to guess at whether you can arrange a LED on some set of pins, to stay on. For the LED to work properly, there has to be a series resistor in series in the circuit, to limit current flow to a safe value. I don't believe that resistor is on the computer case side. It is part of the LED driver on the motherboard. If someone connects the LED cable between raw +5V and GND, the LED would burn out. For the LED to remain lit constantly, it would preferably be on a circuit with resistor in series. So there are some limits as to how many pin combinations on the PANEL header, can provide just the right ingredients. +5V --- resistor ----X X---GND (Panel pins to make a steady LED) If you connected a LED to the RESET pin pair, that would provide a pullup circuit similar to the drawing. And, the LED would pull the circuit down to Vfb of the LED, perhaps still sufficient to not be interpreted as logic 0, and lighting the LED at the same time. I doubt the pullup resistor value on the RESET pin pair, is the right value to make the LED glow at normal brilliance. So there are plenty of nuances, that if someone describes the intensity, when the LED comes on or goes off, you could guess at where it is connected. In my case, my symptoms are bizarre enough, to need software to get involved. My symptoms are not consistent with a wiring error, and look more like the activity state of my LED gets flipped during a Power Management state change. Paul
From: Peter Jason on 11 Dec 2009 17:00
"Paul" <nospam(a)needed.com> wrote in message news:hftu3j$gqr$1(a)news.eternal-september.org... > Jeff Strickland wrote: >> "JD" <No.Reply(a)Sorry.com> wrote in message >> news:4b220f72$0$2535$da0feed9(a)news.zen.co.uk... >>> Peter Jason wrote: >>>> Why? >>>> >>>> Please help, P >>> Hi there >>> >>> As Jeff and Paul say the drive may be in use if you >>> built it yourself connecting the power button to the IO >>> panel you may have put the "PWR Switch" wires in the >>> wrong way round which will cause the light to come on >>> when the drive is NOT in use and off when it is. >>> >>> JD >> >> >> While is certainly possible that the lights are switched, >> if it wasw true that they were switched, then the Power >> light should be blinking to indicate that the HDD is >> being read. >> >> The HDD light is supposed to blink on a random schedule >> as data is being read, if the light is on continuously >> then something is making a call to the HDD causing it to >> read data all of the time. If the HDD lighth is on steady >> and the Power light is blinking, then my money is on the >> connectors being switched. >> >> If the connectors are switched and the machine is Home >> Built, maybe one should give consideration to not >> building any more computers. >> > > There are a couple ways for the LED signal to be created. > You could > use the status signal right off the IDE ribbon cable (with > appropriate > buffering). Or, the status signal could be coming from the > Southbridge > itself, partially under software control. In the case of > my LED, which > turns on steady while my screensaver is running, I suspect > the LED state is being > affected by something the driver is doing. And I've tested > it, by > moving the mouse (to get rid of the screensaver), then > double clicking a disk > icon to get some hard drive activity. The LED actually > blinks off, then > comes back on, as if an XOR gate is present in the circuit > and the > activity state of the LED has been changed (normally ON, > blink OFF). > Roughly ten seconds after the screen saver has stopped, > the LED goes out, > and returns to blinking on in response disk activity. So > my problem is > related to something involving "driver" / "power > management state" / > "perhaps Southbridge". > > We really need a more detailed description of what the > OP's LED is doing, > to decide what it is. If the motherboard has a manual, > with PANEL pinout > and named signals, it may be possible to guess at whether > you can > arrange a LED on some set of pins, to stay on. > > For the LED to work properly, there has to be a series > resistor in > series in the circuit, to limit current flow to a safe > value. I don't > believe that resistor is on the computer case side. It is > part of the > LED driver on the motherboard. If someone connects the LED > cable between > raw +5V and GND, the LED would burn out. For the LED to > remain lit > constantly, it would preferably be on a circuit with > resistor in > series. So there are some limits as to how many pin > combinations > on the PANEL header, can provide just the right > ingredients. > > +5V --- resistor ----X X---GND (Panel pins to > make a steady LED) > > If you connected a LED to the RESET pin pair, that would > provide a pullup > circuit similar to the drawing. And, the LED would pull > the circuit > down to Vfb of the LED, perhaps still sufficient to not be > interpreted > as logic 0, and lighting the LED at the same time. I doubt > the > pullup resistor value on the RESET pin pair, is the right > value to > make the LED glow at normal brilliance. So there are > plenty of > nuances, that if someone describes the intensity, when the > LED comes > on or goes off, you could guess at where it is connected. > > In my case, my symptoms are bizarre enough, to need > software to get > involved. My symptoms are not consistent with a wiring > error, and look > more like the activity state of my LED gets flipped during > a Power > Management state change. > > Paul Thanks to all for the advice. I think I have fixed it by going to a 10-day old system restore. So far the little light is now behaving normally. Perhaps it was some virus, or some fault in some program. P |