Good luck. Used to be you could get a mobo manual from e4allupgraders.
The Imperial board is made by TriGem
Started out as TriGem Sambo, is now TG Sambo
The Imperial models were Imperial G, Imperial GL, Imperial GV, and Imperial GLVE, if memory serves.
TriGem Imperial GV - 143159 -20030812http://www.ebay.com/itm/gateway-emachine-mother-board-imperial-gv-20030812-/111025938736?pt=Motherboards&hash=item19d9a96130
Bad photo, but it does have the mouse Zoom In feature.
CMOS jumper and Clear BIOS Password jumper, down by the Front Panel header; is the same as used on the TriGem Imperial GLVE -129504,http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph07540&lc=en&cc=us&product=83481
Scroll down to Motherboard Layout (Illustration), and Photo; then down to jumper info.
(By the way.........the BIOS chipset is removable, therefore replaceable)
The front of your computer is the Front Panel.
The area of contact pins on the motherboard, that the Main wires from the Front Panel go to; is the Front Panel header.
This is PANEL in the illustration. Bottom/Right corner. Uses the same Front Panel pinout, as your Imperial GV uses.
8 pins along in a row.
Starting on the LEFT side going towards the Right;
Pins 1, 2, 3, NO pin 4, 5, 6, 7, and 8.
A) Pin 1 is N/C. Not Connected
(May not even be there for all I know)
B) Pins 2 and 3 are for the Power On LED.
Pin 3 is for the Positive wire.
If the PWR LED is dim when the computer is on, switch the wires around.
C) There is NO Pin 4. At least that is what I make, looking at the Front Panel header pinout. Indicate Pin 1 is N/C, and Pin 4 is N/C.
D) Pins 5 and 6 are for the HarDDrive activity LED light.
Pin 5 is for the Positive ( + ) wire.
If the HDD LED is dim when the Harddrive is active, switch the wires around.
E) Pins 7 and 8 are for the Power On switch.
HOWEVER, since the motherboard photo on HP Support, and Ebay; is as clear as mud; suggest you do this,
Connect your Power On switch to Pins 7 and 8;
touch across them briefly with a small flat tip screwdriver.
(Power plugged in)
See if that is correct for the Power On switch. What will happen if it isn't? Nothing. Pressing the Power On button just won't turn the computer on; is all.
Turned the Power Supply (Computer) on?
Good. We can assume the rest of the pinout is correct also.
Want to make sure? Easy.
Take an LED bulb (Power On, or HDD), and touch it's two wires to the Power On LED pins, in the Front panel header.
Stays on? Yep. Power On LED pins.
Those are the Harddrive activity LED pins.
Just that easy to check it. With using an LED, you won't harm anything even if the pinout is wrong.
Using the HP Support page, for that TriGem Imperial GLVE motherboard, the Motherboard Layout is the same as the Imperial GV.
(So is photo, 'natch)
Referring to the layout, and photo;
A) Power cables:
20-pin ATX main power cable, and 4-pin ATX +12 Volt power cable.
General example of a 20-pin ATX main power cable, and it's respective connector on the motherboard,http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20
Note* Color of power cable connector does NOT matter.
Can be Whitish, Yellowish, Black, Sea Foam Blue, or Lactating Mammary Gland Pink. (Made the last two up)
Goes to the motherboard connector immediately above PCI slot 1.
Note the LOCK on the side of the power cable, and corresponding TAB on the motherboard connector.
General example of 4-pin ATX +12 Volt power cable, and connector on motherboard,http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4
Power for the Processor
Looking at the motherboard illustration, look at the Northbridge chip; -> Intel 845GL in the middle.
ATX 12V to the left, is where the 4-pin ATX +12 Volt power cable plugs in.
See the aluminum finned Heatsink, sitting on the Northbridge chip?
The whitish/yellowish 4-socket hole square connector, to the Left.
See where it states Primary IDE to the bottom/right in the illustration? Blue IDE connector?
That is where the Harddrive plugs in.
This is a general example of the connector,http://en.wikipedia.org/wiki/File:PATA-cable.jpg
Note the Locating Lug on the top/middle. This particular style uses two ribs. Some are just a solid block.
The reason I brought it up, is if there is NO Locating Lug on the connector; let me know in a Comment.
I'll tell you how to use the faint Red stripe, on the side of the flat cable; in order to plug it in correctly.
The optical drive (CD/DVD drive) plugs into Secondary IDE.
You can see where a Floppy Drive plugs in.
Above the Processor (CPU) socket to the Right, is where a computer case fan plugs in. PS_FAN.
To the upper Left, is where the Processor fan plugs in.
To the left of the ATX Power Connector, (20-pin ATX main power cable; motherboard connector), is the connector for the small audio cable; coming from the optical drive. (CD/DVD drive)
Optical Drive In.
Right next to the round CMOS battery, is the Front Panel USB header.
-> TWO USB ports connect to this header.
A 4-pin Peripheral power cable is used for the Harddrive, and Optical Drive.
Misnomered as 'Molex' power cable,http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral
Note the rounded corners. When plugging the power cable in, these rounded corners always go UP.
[Molex was the first maker of the power cable connector.
The name stuck.
Kind of like calling an adjustable open-end wrench a 'Crescent wrench' ]
The motherboard chipset is an Intel 845GV.
This is what Processors (CPU), and Ram Memory are supported,http://en.wikipedia.org/wiki/List_of_intel_chipsets#Pentium_4_chipsets
Use a Socket 478 processor socket.
Intel Pentium 4, Celeron, or Celeron D.
(Celeron D is NOT a dual core processor)
400 to 533MegaHertz Front Side Bus processor support.
DDR Sdram ram memory that is either 266MegaHertz, or 333MHz.
(PC2100 and PC2700, respectively)
2GB's of it.
1GB for EACH ram memory slot.
For additional questions please post in a Comment.