This is a common and not too difficult to fix problem. Well, not common as in it happens all the time but common as in when something goes wrong this is often it.
the diagnostic lights are one of Dell's more redeeming qualities for sure. Having them show Green, Yellow, Green, Yellow (A=Green, B=Yellow, C=Green, D=Yellow) is usually a memory issue. The beeps you desccribe also indicate a memory problem.
The Dell manual shows this:
Memory modules are detected, but a memory configuration or compatibility error exists.
It then lists the following trouble shooting steps.
- Ensure that no special memory module/memory connector placement requirements exist.
- Verify that the memory modules that you are installing are compatible with your computer.
- If the problem persists, contact Dell.
The most likely problem is that one or more memory modules installed are not compatible with your system. The only thing that leads me to believe otherwise is that your problem is intermittent. Obviously a memory module would not randomly change type. Which leads me to one solution Dell does not list for this error code.
Re-seat any memory modules installed in your system. Take the following steps:
- Shut down your computer and disconnect the power
- Remove all memory modules
- If you have access to compressed air, blow out the slots to make sure there is no dust
- Place the modules back into the slots and make sure they are firmly seated and the tabs are secured (do not force them into place, if there is too much resistance then they are not aligned properly)
If the problem persists and you have more than one memory module:
Remove them one at a time and try again. It is possible that one module can be defective.
