I'm currently having an issue with my PC. I own an HP slimline tower and as of recently, it's been giving quite a few problems. one of the major ones is the PC constantly crashing and rendering the monitor display into a series of blocky images. I've had this tower for all of 5 years by now and it's had this issue once before, but, now it's becoming unbearable. I don't know exactly what this means, but, it concerns me quite abit. does anyone know what this issue is and how I can go about fixing it? thank you in advance.

why new PSU,? if PC dead before say so we fix that. ask.
slimlines use a custom HP PSU, not standard ATX.
the PSU on these also have HP custom fan controls from PC mobo
to the PSU, and will fail using any generic ATX psu.
IT NEEDS TO BE HP ONLY PSU, correct HP P/N#
NO PSU LABEL POSTED BY YOU
NOR THE SOURCE, NOR IF A USED PSU.
and both DC power wires, 24 and 4 pin must be connected or the CPU will be dead. 2 key power cords one goes near CPU,see?
some PSU have 120./240ac switch on the rear, and must not ever be set wrong, and is frankly step #1 OOBE. it..

what is the problem?

most likely power supply, those power supplies are horrible and the slightest power surge cooks them. a majority of them I get in for repair are p/s issues, a few for mobo issues.

Try a different monitor. If that works, your old monitor died and you need a new (or used) one.

Try monitor self test. If passed, problem is with computer tower.
This issue can easily be resolved at http://sureconsulting.in/

I've just had a look at this web site :-

http://www.ehow.co.uk/facts_6791518_specifications-slimline-s3123w-pc-maximum.html

And it says the your PC did come with both a The HP Pavilion Slimline S3123W had a 56k data/fax modem and an integrated 10/100 Base-T networking interface.

There's more info and help, including user guide here :-

http://h10025.www1.hp.com/ewfrf/wc/searchResults?tmp_product=HP+Pavilion+Slimline+s3123w+Desktop+PC&product=3442918&tmp_qt=user+guide&lc=en&dlc=en&cc=uk

Ask AT&T if you need an ADSL modem or an old data/fax type modem. If its an old data/fax modem, you should be able to plug your phone line, may need the proper cable, into the back of your PC.

If they provide ADSL connectivity, then you'll probably need a modem, ask them to give you one or buy one from ebay or a shop. Should be really quite cheap. You may have a friend who could give you one because these are quite old technology now. Most people are now using a wireless router.

It may be worth searching on "youtube" for videos which show you how to do much of this.

its ok just POST TO HP PC or HP Desktop, with tag data.
for sure fixya does not have all 10,000 HP PC's listed nor will it ever.
H3LL even HP dont. (shock)
a desktop PC, (easy to fix , them all) no magic and ATX spec.
standards in play.
why not do the tests in the correct order.?
and do not put other HDD os in to your box, or the reverse.
that will not work.
first off the screen is black.
so you go in to BIOS, does it work and stay working there.??
that is first no the HDD, we play with OS later.
make the screen work first
see that VGA jack on rear of PC
try a different screen see if you can get to BIOS and hold there for say 5minutes, or more?
if that fails ?
this is an Emachine, with no video card, (or was added later,did you look>)
all Emachines, if you add at Video card, you must turn off the on MOBO GPU chip 6150LE
or it will get very confused. (which to use)
only you know if rear side, has x2 ,15pin VGA ports on the rear
if only one there, then its lock box stock, ORIGIONAL.
it only has 1 PCI-express 16x slot for added VGAG card.
if present remove it, and use the normal JACK
the goal is to get one of the 2 VGA jacks to work
that take owning 2 monitors, lacking a second, barrow one.
BIOS work now?
http://support.hp.com/doc-images/234/c00910084.jpg

BIOS hot keys (F1, F9,f10, esc, delete key)
the book on your machine tells you which hot keys work on your PC. and must be known by you or diagnosis goes to hair pulling.

http://jeepdied.com/look/puters/dead-screen.html

not yours but will look same with your exact model
try to know there are many sub models on all HP systems.

You need to install Virus scanning software. There are quite a few commercial one available such as McAfee and Nortons. There are also some freeware ones on the Internet, AVG is one, Google the Internet for others.

Try to change the RAS...

This is One of the Known Issues on Hp Products...

There are Updates Released by Hp for Most of the Model facing this issue...

The Products for which the Solution (drivers) have been Released so far in the DX series are...

HP Compaq dx6100 Microtower PC

HP Compaq dx6100 Slim Tower PC

HP Compaq dx6120 Microtower PC

HP Compaq dx6120 Slim Tower Desktop PC

HP Compaq dx6128 Microtower PC

HP Compaq dx7200 Microtower PC

HP Compaq dx7200 Slim Tower PC

HP Compaq dx7208 Microtower PC

HP Compaq dx7300 Microtower PC

HP Compaq dx7300 Slim Tower PC

Your Product is not listed.
You got to Report with the HP and they Will update you once they have a Driver for you,
However what you can do is try and run BIOS update if Possible.(it may not be Possible in a Boot issue though).