HP DC7800P SFF, POWERS UP BUT NO DISPLAY, RED LIGHT BLINKS AND BLEEPS SEVERAL TIMES

It means you do have a LCD panel back lights problem, in most of the case, a defective back lights inverter could be the cause.

The red light and beeping indicates a fault. The fault code number will be indicated in the display or by other LEDs being lit. If you post back with the details of the display we may be able to help you.

check connections

It will blink a number of times, pause, start again.

You need to count the number of times the LED blinks between pauses.

then go here to see what the box is trying to tell you

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00274415

Here is a link.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00274415

Make sure it is four beeps, as that is not listed here.

However, It does mention other things you can look for (like looking at the power LED during power up to see it it blinks).

When you machine powers up, it has a certain manufacturers BIOS installed. These are additional beep codes for different BIOS manufacturers. You can tell which BIOS you have when you first turn the machine on, the name should be listed (Phoenix, AMi, etc..)

http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=bph07107#N697

here is a link to the service reference card for thew system.

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c00067072/c00067072.pdf

Similar to the first link but more detailed.

change your memory ram with the same specification.

Well with out doing a whole bunch of research on your device I would say there is a back light problem you will need to buy a new display

5 beeps is a mainboard failure. More specifically a processer CPU chip problem. Take the cover off and make sure your Processor isn't loose.

The processor is underneath the fan. More importantly, this problem could be caused by the fan not working. Make sure your fan is always turning at a high speed. Not just barely turning or completely stopped

I get 5 blinking red lights for about a minute or so before it powers back down. The Sony TV has a specific light that i presume is supposed to light up when the bulb is out. I'm unsure if this is what it is.
no picture, no sound. tries to boot with green light blinking a few times. then goes to red blinking light, six in all, then waits a few moments, then another 6 blinking red light.
Bulb was already replaced several months ago but we do have the TV on for long periods of time.

My TV did the same thing today. My red light blinks 6 times. Any help would be much appreciated!