Saturday, November 3, 2012


Date & Time Reset ON PC

Replaced CMOS battery but still Data & Time resets on PC.

In such case first test voltage of CMOS battery.
The CMOS battery is 3 volts battery. If the battery is showing fewer volts, then try another CMOS and see if that is helping.

The possible reasons for Date And Time reset on Motherboard: -----
1) A faulty CMOS Battery.
2) No VBAT voltages on Super IO chip.
3) Faulty IO chip.
4) Faulty CMOS battery Slot or loose soldering of CMOS battery slot.

The possible solutions for these problems are as follows: ----
If CMOS battery is very old or showing less then 3 volts (say 1 or 2 volts) then replace CMOS battery cell.

A Vbat voltage is received on IO chip. Test the Vbat volt on IO chip. For which pin is VBAT pin on IO chip. Just get datasheet for IO chip. To retrieve datasheet, just goggle search the serial number of IO chip and you will get the datasheet. It will tell about what pin of IO chip is called what. You have to test 3 volts on VBAT pin of IO chip. If these voltages are not there on IO chip, then apply jumper from positive solder point to VBat pin of IO chip.
These will solve the problem.

NOTE: VBat voltages are CMOS battery voltages supplied on Super IO chip. For testing these voltages, no need to connect SMPS connector. The voltages will just show up on IO chip VBat pin.

In case if you apply jumper on VBat pin of IO chip, but still the Date and Time Issue is getting reset again n again then its faulty IO chip and it has to be replaced.

But before replacing the IO chip, please consider replacing the slot where CMOS battery is inserted in motherboard. Because on many motherboards, it’s seen that replacing the CMOS battery slot, solves this typical problem of date and time reset.

Sometimes the CMOS battery slot connector solder pins get bit loose and re-soldering these loose soldering pin helps.

Cleaning the components before replacing is always advisable.
Many a times dust or moisture gets collected in between two pins and these causes not necessary connections ,so cleaning the soldering joints or chip pins with IPA helps.
Before replacing any component, clean the components with IPA, then let it dry for few minutes, and then see if the problem is still there or not.

These details will help.

For more help regarding motherboard troubleshooting, go through the help links provided below: -----

Troubleshoot Dead Motherboard

Troubleshooting NO Display Problem on Motherboard

Troubleshooting CPU Overheating Problem on Motherboard

Desktop Motherboard Cpu Fan Connector

No SMPS Power Good on Super I/O Chip

MCH OR ICH Heating on Motherboard

Desktop Automatically Turns ON

Motherboard Immediately Restarts

MotherBoard Will Not Start With 4-Pin ATX power connected

PC Motherboard System Hangs Or Very Slow

Colors Missing On Display

USB Port not working on Motherboard

Motherboard USB Connector Pin details

PS2 Port Not Working On Motherboard

Motherboard HDD not getting Detected

Fix For BIOS Corrupt