The Dimension 8400, purchased 4 yeasrs ago, suddendly froze up and would no longer boot. The rear panel lights and the front panel switch light would not light at all. When power is disconnected and reconnected the power supply (REV A04) and fans briefly enable and after 1 sec. disable. But no system boot.
I have completed the following diagnostics:
1. Cleared CMOS (disconnect power; wait for MB light to go out; removed battery; cleared pushed front panel button for 30 seconds;reset battery; reconnect power). *** The system actual boots up after 2-3 seconds. But on the next shutdown the problem comes back ***
2. Same as above but start the system without the battery reinstalled. *** Same result - The system actual boots up after 2-3 seconds. But on the next shutdown the problem comes back ***
3. a) Removed all components (disconnect power; wait for MB light to go out; removed battery, NVRAM, cards; reconnect power). MB lights and beeps. DELL Tech informs me this is the MB complaining that there is no NVRAM and an indicator the MB is OK.
b) Then disconnected power and installed one NVRAM in Slot 1 and connected power back to system. System does not boot.
c) Tested NVRAM in another system. Both (had 2 x 512MB) were bad!! Purchased new NVRAM and installed only one back into slot 1. Added back all cards checking for goot connector fits and card connections.
d) System reboots only if #1 and #2 above are done. Front panel button switch does not work but light is green on the front button.
4. Configured BIOS Power Management so Reboot when power restored after outage is set to ON. Disconnect power for 30 seconds so the MB light goes out. Reconnect power and 2-3 seconds later the system boots up no problems, all lights green, no errors.
So I can keep the system going so when finished with it, shutdown as normal, disconnect power at back and reconnect power at back when the system is again needed (time disconnected from power must be greater than 30 seconds). The system automatically boots up when power is restored at back of system.
I hope, should someone have experienced this problem, provide me kindly with insight to the following:
Any insights into this dilema whould be greatly appreciated.
Thank you very much for your reply. I will check my power supply output. However the power is enough to drive the system once the battery is replaced and the system BIOS Power Management is set to Reboot when power restored after outage is set to ON. The only thing that now appears wrong with the system is that after a shutdown I cannot restart the system with the front power button. I must disconnect the power, wait 30 seconds for the MB green light to go out, then reconnect the power. The new BIOS Power Management setting causes the system to boot up automatically. All is well.
So the power drives the system. There is no error messages on boot. All lights are now green.
I will replace the battery Tuesday - long weekend in Canada - to be sure. I have been searching the web but so far unable to find the CR2032 tolerable voltage levels. Mine measures 2.86V. This seems close enough to 3V and does maintain the NVRAM BIOS settings, etc.
The power cables and capacitors are all OK.
When all cards and memory are disconnected the MB beeps .. Therefore it appears the MB is OK.
I will validate the Power supply .. thank you for the instructions. But as I commented to Digital28, the power supply seems to be working great powering everything on the system.
I am beginning to suspect the front panel power switch is broken. Yet the LED still works.