To be honest, nowdays any beep codes are usually memory or video card errors. Award BIOS only has 1 beep code now, meaning cideo display is borked. Everything else it spits up on screen.
Did some searching, maybe this is it?
If it isnt that, then I'm not sure, as all the Compaq's have are 4 sets of beeps.
link to bulletin
RELEASE DATE: December 2001
DESCRIPTION
Unit will not post and produces a 3-1 beep code error (CMOS RAM Test Failed).
SCOPE
Presario 12XLxxx series notebooks using ROM versions F.05 (08/16/00) and earlier.
12XL3, 12XL300A, 12XL301, 12XL302, 12XL303, 12XL304, 12XL305, 12XL307, 12XL310, 12XL311, 12XL312, 12XL320, 12XL323, 12XL325, 12XL326, 12XL327, 12XL330, 12XL4,12XL402, 12XL403, 12XL405, 12XL406, 12XL407, 12XL408,12XL409, 12XL411, 12XL412, 12XL413, 12XL414, 12XL416, 12XL421, 12XL502,12XL506, 12XL507, 12XL510, 12XL512, 12XL521,
RESOLUTION
The failure to boot and the 3-1 beep code has been identified by a code failure in the F.05 (08/16/00) and earlier ROM's. This has been corrected in the ROM revision F.0E.
If the unit already is producing the beep code error, have the unit serviced by an authorized service center.
To prevent the unit from producing the 3-1 error code, down load ROM revision F.0E (SP19395.exe) or later.
Compaq Softpaqs are available for download from the Compaq WEB site,
http://www.compaq.com/support/files/allsp.html orhttp://web14.compaq.com/falco/sp_list.asp orftp://ftp.compaq.com/pub/softpaq/
HARDWARE PLATFORMS AFFECTED: Presario 12XL
COMPONENTS AFFECTED: System/Processor Board
OPERATING SYSTEMS AFFECTED: Non-OS Specific
SOFTWARE AFFECTED:
THIRD PARTY PRODUCTS AFFECTED: None
DOWNLOADABLE FILES: SP19395