Dell n4050 7 beep - Inspiron Dell Computers & Internet

Perhaps this will help: http://www.nullamatix.com/dell-diagnostic-beep-code-troublshooting-chart/ OR: http://factfetcher.blogspot.com/2011/04/beep-codes-computer-problem-issues-dell.html

Here is a link to your computer's service manual:
ftp://ftp.dell.com/Manuals/all-products/esuprt_desktop/esuprt_xps_desktop/xps-400_Service%20Manual_en-us.pdf
There is a section on Advanced trouble shooting which details Beep codes and LED diagnostic codes.

This WEB site gives the BEEP codes for the Dell.
http://en.community.dell.com/support-forums/laptop/f/3518/p/19447544/20098900.aspx

This WEB site gives details of the Dell POST beep codes.
http://www.nullamatix.com/dell-diagnostic-beep-code-troublshooting-chart/

If an error occurs during startup that cannot be reported on the monitor, your computer may emit a beep code that identifies the problem. The beep code is a pattern of sounds: for example, one beep, followed by a second beep, and then a burst of three beeps (code 1-1-3) means that the computer was unable to read the data in NVRAM.
YOu can find complete table on Dell support site.

Most of such errors can be fixed with a system utility software RegInOut

the 6 beep codes will be in a specific timing i.e. two beeps, a space 2 more beeps, and another space and 2 more beeps.

Looks like it may be a memory problem according to the lights.

Possible memory failure

Reseat all DIMMs and restart the system to retest.

Here is the link to the beep codes and diagnostic lights for your dell optiplex gx 150 HERE

The Beep codes are in Table 2 and the diagnostic lights are in Table 3.

Note down the beep rhythm. The table of Dell "Beep Codes" will tell you what's wrong in the computer (could me memory, CPU, bus, or video card).

Here you go:
http://www.nullamatix.com/dell-diagnostic-beep-code-troublshooting-chart/

The exact meaning of the beeps for Dell depends on their... rhythm.

http://www.nullamatix.com/dell-diagnostic-beep-code-troublshooting-chart/

Six beeps might indicate a simple CMOS failure caused by a bad battery, which is easy to replace.