i have an issue with my motherboard.. usb keyboard was not working on the initial screen.. initial screen stays at "checksum error press f1 to contine f2 to setup". so i tried to reset cmos by removing the battery/connection clear pins on jumper cable but the issue persists. so i decided to check the power supply including the battery and they read well except the white pin which reads +4.97 but it should be -5v. Wondering if this would cause an issue for checksum error or usb mouse/keyboard not working.. any advice is welcome.. i am also thinking of getting a replacement motherboard from ebay..
PSU white reading +4.97 instead of -5v
- Thread starter Thenn
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When i checked through multimeter i had connected black(ground) tp black multimeter and the colored wires to the red one in multimeter. For -12v power supply(blue) it read as -19.98v so i was expecting the white should read as around -5.5v. Here are my readings from various colored wires in PSU.
cmos battery = +3.1V
+12v (yellow) = +11.99V
-12v (blue)= -11.98V
+5v (red) = +5.13V
-5.5v (white) = +4.97v
+3.3v (orange) = +3.36v
+5v standby (purple) = +5.04v
does this corealte to the issue iam having (usb keyboard) not working during the initial screen when the message reads "checksum error press f1 to continure"
- Apr 22, 2009
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Are you taking the reading at the 24 pin connector on the PSU? There is no -5V. Just +5V*. And the white wire is suppose to be (NC). But I can't see any way that issue would relate to a checksum error. All your values are within the allowable tolerances.
* Older PSUs used to have a -5V for the ISA bus, but that is now obsolete.
* Older PSUs used to have a -5V for the ISA bus, but that is now obsolete.
clutchc :
Are you taking the reading at the 24 pin connector on the PSU? There is no -5V. Just +5V*. And the white wire is suppose to be (NC). But I can't see any way that issue would relate to a checksum error. All your values are within the allowable tolerances.
* Older PSUs used to have a -5V for the ISA bus, but that is now obsolete.
* Older PSUs used to have a -5V for the ISA bus, but that is now obsolete.
i meant -5.5v.. not -5v. sorry. what next step would u suggest for me? can i go ahead and buy the same model motherboard or a new one that can take in my current processor/power supply etc?
- Apr 22, 2009
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And it reads -5.5V to ground at the white wire? It must be a throwback to the old ISA days. That wire isn't used any more. So that is not your problem.
Does the mouse (or any other USB device) work if plugged into the USB port that the KB was plugged into?
Does the mouse (or any other USB device) work if plugged into the USB port that the KB was plugged into?
When i connect mouse to the same usb i was connecting KB - i see the light comes up and stays on where as the keyboard caps/scroll/num keys blinks once initially and then goes off.. my tries to turn on the caps/scroll/num lock keys are not working... there is no way for me to tell if the mouse works in the checksum error screen..
- Apr 22, 2009
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So basically, you are stuck at the boot screen, can't enter Windows... right? The problem could still be the PSU, just not the -5.5V issue. It could also be a failing MB. Do you have a PS2 KB that you can use to see if it works? Or a PS2 mouse? Or is that one of those old inexpensive boards with no PS2 ports?
- Apr 22, 2009
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I'd flash the BIOS only as a last option. But put a fresh CMOS battery in just to be sure that isn't adding to the issue. That board and its battery is several years old. Those batteries don't last forever. Do the front panel USB ports on the case work?
yes. front panel usb is connectd to the mb.. so a failed keyboard controller means i can go ahead and buy the same model motherboard from ebay.. i am looking in this one and the seller claim the motherboard is tested and he accept returns if it does not work..
http://www.ebay.com/itm/141373338241?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
also i read in a different tomshardware.com post that the DG33BU motherboard would be a replacement to dg33m05(one i am having issues with).. what u think would be best? i would still want to go with my existing model but if u think dg33bu is best then please let me know.
http://www.ebay.com/itm/Intel-DG33BU-LGA-775-Motherboard-microATX-G33-Express-Chipset-D79951-411-/301277392987?pt=Motherboards&hash=item462588305b
- Apr 22, 2009
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First, let me remind you that my troubleshooting from afar may not be totally accurate. It's not like having the system in front of me with the necessary equipment. But from our discussion, my GUESS would be that the on-board USB controller (located on the south bridge) has died. You could try flashing the BIOS with the latest version available as a final check to see if it is firmware related.
If you decide to try replacing the MB, I would get the exact same one you have now for the least problems. Your OS (Win7?) will see a different board if there is much difference, and possibly assume you are trying to use the OEM licensed OS on a 2nd machine. If that happens, you'll have to "jump through a few hoops" to get it re-activated.
Also, if you replace the board with an exact duplicate, there's less chance you'll have to install new drivers for the on-board devices.
The seller seems to have a lot of sales with no bad feedback. That is usually a safe seller to buy from.
If you decide to try replacing the MB, I would get the exact same one you have now for the least problems. Your OS (Win7?) will see a different board if there is much difference, and possibly assume you are trying to use the OEM licensed OS on a 2nd machine. If that happens, you'll have to "jump through a few hoops" to get it re-activated.
Also, if you replace the board with an exact duplicate, there's less chance you'll have to install new drivers for the on-board devices.
The seller seems to have a lot of sales with no bad feedback. That is usually a safe seller to buy from.
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