My PC dosn't work

"i can find my dmm?" did you mean CAN'T?
"its clearly off", what is off?
the fans are 3 pins,2 are power, one is RPM tachometer.
"it all works fine", so you can boot and run any OS, ?

"the voltage reads +12vdc", where, at fan or PSU?
the fans run off 12vdc, they are DC motors (from outside fan)
if the fan runs slow at 12vdc the the fan is bad or is a low RPM
fan, as some are, bigger fans run slow, for less noise.!

first is the CPU fan it must run full speed, if not the CPU will overheat in seconds and ALL CPU shut them selves (by there selves) this way. so CPU fan is first. what does it do... there....?

then BIOS screens. GOT BIOS UP? and running? with, ESC key pressed>.
let me guess your symptoms
1: PC dead. will not boot.
2: BIOS dead.
3: all fans DEAD,.
4: power switch works and all PSU voltages read right, (seems not)/?
5: if the PSU power wire reads right(DMM), matching the side sticker voltages, and the CPU is dead, the MOBO is dead, or CPU is toasted.


here is a modern PSU, sticker.
see 5 to 10 power lines, see them. all must read correctly
if a fan is dead, then its dead if 12vdc is present on the fan power pins.

hello iam vishal i will tell you the solution,
1)open the cpu
2)clean all the parts with a cloth
3)remove harddisk ,cmos battery and for reinsert after 5 minutes
4)remove the wire and re-attach all the pc wires
run the pc
5)problem is solved

The power supply is defective and it needs to be replaced, if the computer is still under warranty then contact Compaq if it's out of warranty then either buy a power supply to replace yourself or bring it to a computer shop to get it replaced.

can I buy some puctuation?
i can not understand most of that.sorry....
D330 PC, check
unstated monitor, what monitor of 1000s/?
post all that works and not, only all facts solve problems
we are blind here, cant see you or it. (those parts)
"displayed fan pin" i read that 10 times and draw a blank...
i see your screen is not dead ,it prompts you with text
I bet the BIOS hot key work , do they ,sure.
OK yes, the F1 joy, this is when BIOS discovers that the COIN cell is dead, as all PCs are this old,
dead dead dead, its just $2 coin cell battery

see this
https://support.hp.com/us-en/product/hp-compaq-d330-desktop-pc/342066/manuals

see
service man
http://h10032.www1.hp.com/ctg/Manual/c00059138


see page 46
BINGO, coin cell *****.
wow it lasted 11 years, , that be like a world record
Id frame the sucker.

what error or msg you receiving.
if its asking for go to setup(bios)
then go & restore default configuration

search this site...
http://www.sparepartswarehouse.com/Compaq,Computer,Part,308615001.aspx

power supply
to motherboard..

put the power connector to power socket of the motherboard..plus the 4pins connector to the 4pins socket into motherboard..

put the power connector of power

then connect the fan to a 2-pin connecter if you cant do it take it to a computer place to do it for you

Here's a link to a video that should prove to be useful...
http://www.wonderhowto.com/how-to/video/how-to-install-a-pc-power-supply-9043/

there are several possibilities. 1. replace the ram, make sure that its a good working ram module. 2. review all your work from system board to power supply. 3. try running it temporarily without the cmos battery. 4. check your monitor. 5. check your VGA. 6. retry and retry.

Hey,

download and install the driver again from the hp site
http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?prodNameId=342068&lang=en&cc=us&prodTypeId=12454&prodSeriesId=342066&taskId=135


Let me know if you need anything else.


Thanks,
Ekse