I have a Dell Dimension 8400 that will not turn on. I tested multiple power sources and power cables, made sure the psu was on 115. I replaced the CPU, motherboard, front panel switch, I/O control panel and cable, and the cpu fan and hood. I shorted the P1 connector which turned on the psu and tested it with a voltage meter and it read 5 and 12 v as it should. At this point I've replaced or tested everything in this machine that would prevent it from turning it and still nothing. Will a bad video card or ram prevent it from turning on? WHAT IS WRONG WITH THIS PIECE OF ***!?!!?!!?!!
Breadboarding is when you build the system outside of the case.
Start by removing everything from the motherboard, except for the CPU, heatsink, and heatsink fan.
1. Place mobo on a non-conductive surface (such as cardboard or wood)
2. Connect the PSU (remember to connect the 4/8-pin connector near the CPU)
3. Use a flatheat screwdriver (or similar tool) to jump the power switch pins on the mobo.
At this point you should hear a series of beeps: 1 long, followed by 2 or 3 short. If you hear these beeps, your mobo has performed POST, but halted at the memory test. Continue to step 4. If you didn't hear the beeps, ensure you have a case or mobo speaker, and if you do have a speaker and didn't hear beeps, your board is likely dead.
4. Continue by installing RAM one module at a time. If you hear the series of beeps again, remove the last installed RAM module and try a different one. This is how you rule out bad RAM or bad RAM slots.
5. Once the RAM is successfully installed, continue by installing your GPU or connect your monitor to the mobo. If you see display on your monitor, you will also see an error message stating no hard drive detected.
6. continue by connecting your hard drive. If no errors are found, continue to add the rest of your hardware one at a time.