Working on dell dimension 3100/e310 desktop pc. when u press the power button u get a soid green light with beeps and the diagnostic light are green on lights numbered 3 and 4. need help badly

if the beep pattern and led light pattern it's a memory problem, try reseating the RAM. Problem and solution is described multiple times here
Dimension E310 won boot up 6 beeps
21.June.2015

Try here, They are the Vista 32-bit drivers, http://www.dell.com/support/home/us/en/19/product-support/product/dimension-3100/drivers?c=us
or try try the XP drivers.

Try here, They are the Vista 32-bit drivers, http://www.dell.com/support/home/us/en/19/product-support/product/dimension-3100/drivers?c=us
or try try the XP drivers.

Welcome to the user forums. Lights 3 and 4 on indicate a memory failure issue. Suggest unplugging computer, open case, then remove and reseat the memory modules. Diagnostic codes shown here: http://support.dell.com/support/edocs/systems/dim3100/en/sm/adtshoot.htm#wp1124612
See this for removing modules: http://support.dell.com/support/edocs/systems/dim3100/en/sm/parts0.htm#wp1043338

Contact technical assistance.They will most likely ask you to send it back to repair.

This chart is where I got my conclusion.

Power Light

Problem Description

Suggested Resolution
Solid green
Power is on, and the computer is operating normally. On the desktop computer, a solid green light indicates a network connection.
No corrective action is required.
Blinking green
The computer is in the suspended state (Microsoft® Windows® 2000 and Windows XP).
Press the power button, move the mouse, or press a key on the keyboard to wake the computer.
Blinks green several times and then turns off
A configuration error exists.
Check the diagnostic lights to see if the specific problem is identified.
Solid yellow
The Dell Diagnostics is running a test, or a device on the system board may be faulty or incorrectly installed.
If the Dell Diagnostics is running, allow the testing to complete.
Check the diagnostic lights to see if the specific problem is identified.
If the computer does not boot, contact Dell for technical assistance.
Blinking yellow
A power supply or system board failure has occurred.
Check the diagnostic lights to see if the specific problem is identified.
Solid green and a beep code during POST
A problem was detected while the BIOS was executing.
See "Beep Codes" for instructions on diagnosing the beep code. Also, check the diagnostic lights to see if the specific problem is identified.
Solid green power light and no beep code and no video during POST
The monitor or the graphics card may be faulty or incorrectly installed.
Check the diagnostic lights to see if the specific problem is identified. See "Video and Monitor Problems" in your Owner's Manual.
Solid green power light and no beep code but the computer locks up during POST
An integrated system board device may be faulty.
Check the diagnostic lights to see if the specific problem is identified. If the problem is not identified, contact Dell for technical assistance.

HERE is the documentation straight from Dell. It gives the explanation of the beep codes and other diagnostic information like what the lights mean. It's the best place to start.

If the POWER Button on the TOWER is blinking AMBER (Yellow) then the most likely failure point is the POWER SUPPLY in the Tower.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817226001

if the power button was blinking amber, unplug your tower, and hold the power button for 30 seconds to 1 minute, to use any excess power stored in the capassitors in the pc. this was told to me by a dell tech, it is a small issue with the 3100=E310, and 5150=E510 Dimension desktops

Hi,

here are a few things to try.
remove the power lead from the computer, for 5-10 minutes then reconnect.
press and hold the power button, for more than 3-5 seconds, incase the system has gone into hibernation/standby mode.
Remove any un-necessary connected devices ( usb powered Printers-cameras et,c )

Mike @ Compurepair.

The processor might be shot........