Hi,
I dont know if this is the right place to post, feel free redirect me if its wrong.
Im going to install debian on an old computer and use it as a server (web/ftp) but wen i try to boot it i get no image (not even in bios) an gives me a warning signal (*long* *short* *short* *short*) and then (at least sounds like) it continues booting. If i unlug the monitor after a while it says "No Connection Check signal cable" and if i plug it in again the message disapears but there is still no image. I only need the monitor to work for the installation.

You probably have a video card failure. Have you tried using a different monitor?
Each BIOS manufacture has a different set of codes.

http://www.computerhope.com/beep.htm

i googeled some and found this about the motherboard:

ENHANCED IDE
2 x Ultra DMA/33 IDE ports (up to 4 Devices)
I/O INTERFACE
1 x Floppy port (360KB ~ 2.88MB)
2 x Serial ports (16550 UART compatible)
1 x Parallel port (EPP/ECP)
AT style keyboard
PS/2 Mouse
Dual USB headers
Supports Creative SB-LINKTM
EXPANSION SLOTS
3 x PCI 32-bit slots
2 x ISA 16-bit slots
1 x AGP slot
POWER MANAGEMENT
Wake-On-LAN
Modem-Ring-On
Power On by Keyboard, PS/2 Mouse, RTC Timer
Power On by "Insert" key when system boots fail
Power Off by Windows 95/98 shutdown & PS-ON power button
PROTECTION(option)
Thermister cable to detect the temperature of Pentium II Processor
Speaker Alarm when CPU Overheat, Fan Failure or Wrong
System Voltage
System Health Status Detect & Report by BIOS & LDCM
SYSTEM BIOS
1 Mbit Flash ROM
Award PCI BIOS with Green, PnP, DMI, INT13 Extension, ACPI, and Anti-Virus functions
LS-120, ZIP, SCSI and CD-ROM bootable
Year 2000 compliance
UTILITY
Intel LDCM (LANDesk Client Manager) Utility (option)
Ultra DMA/33 Enhanced IDE Driver
AwardBIOS Flash Utility
Pentium II Patch-Code API Utility
Intel PIIX4/PIIX4E Utility
DIMENSIONS
AT Form Factor, 22.0cm(8.6") x 26.0cm(10.2")
AT & ATX Power Connectors on board

maybe the graphic card is not seated correctly or its fubar. If anyone has any other suggestion please tell me.

i think the graphic card is a Trident 3D Image 9750.
I tried re inserting it but still the same error. So most probably its dead or the agp port is dead (witch i dont think). i havnt done anything with the computer for quite a looong while (2-4 years), its only stood in the cellar. and the rest seams to work (HD and cd + cpu and fans).
By the ay i also found this:

Award BIOS 286, 386, and 486
Indicator Message
One Long and Three Short Beeps Keyboard Controller Error

but i dunno if i have one of those.

Could also be bad memory too.

ok, il try re inserting the memmory stick

At first I was going to suggest checking the keyboard (Seems to me I've heard that beep code before; it seems to be common to a lot of different systems). The you wrote: You mean no memory was installed? No wonder the POST was complaining.

You're not yanking our chains, are you? It is, after all, April 1st.

No im not, i ment taking the memory out and put it in again

Weheee ^_^ it worked.