Dionex 3100 VWD lamp ignition fails lamphouse cooling fan has 0% power

The ballast might have gone bad, you'll need to check the output voltage of it. In some projectors, the power supply/ballast are combined as one PCB instead of 2 separate boards.

Fans fail rarely---two years is average life for a lamp--at least take lamp out to examine it to see it is not shattered inside.

I concur with your diagnoses.

Weak power supply due to a weak, or failed, voltage power rail.

There are three main voltage power rails for your Dell Dimension 3100 power supply.

1.The 3.3 Volt rail
2.The 5 Volt rail
3.The 12 Volt rail

Newer computer power supply's are doing away with the 3.3 Volt rail.
Your power supply has,

16 Amps on the 3.3 Volt rail,
21 Amps on the 5 Volt rail, and
21 Amps on the 12 Volt rail.

These are the main power voltage rails.
Voltage times Amperage = Wattage.
You have a power supply, that is rated at a maximum output of 400 Watts.

1) ALL the lights use less than 1 Watt.
2) EACH fan uses 2 to 3 Watts
3) A typical processor uses 55 to 125 Watts.

(A typical Intel Pentium 4 HT processor, Model 640, (3.2GHz), uses a maximum of 84 Watts,

http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_microprocessors#Prescott_2M_.2890.C2.A0nm.29

With a weak, or failed voltage power rail you don't have enough power to turn on the processor.
No processor running there is nothing to run the operating system. (Windows XP is an example of an O/S)

The harddrive just sits there, and spins, or will spin a few times, and stop.

What causes this?
1) Cheap quality power supply, (SMPS), installed by computer manufacturer. Cheap components are used in the power supply. (Electrolytic Capacitors, gauge of wiring, rectifier bridge, and so on)

2) Inside of computer, and power supply hasn't been cleaned on a regular basis.
Causes havoc inside the computer.

The processor fan builds up with dust, dirt, hair, etc, and the cooling capacity drops tremendously. Eventually the processor turns off. (BIOS turns it off)
It's a Fail safe feature that is built-in, to keep the processor from burning up.

Before it get's to the stage of overheating, and turning off, it calls for more power from the power supply.
The power supply works overtime to keep up.

When the inside of a power supply, and it's cooling fan are clogged with the above mentioned gunk, the cooling capacity of the power supply also drops tremendously.

The heatsink's inside the power supply cannot get rid of the heat. The fins are clogged, and air cannot rush through them to disperse the heat.

When the blades of the fan, and it's center hub become clogged, the cooling capacity drops due to not enough air is passed.

Heat = Wasted Energy, and the power supply strains to keep up. Eventually components inside the power supply start to fail, or fail.
(Electrolytic Capacitors are usually the first to go. They are the weakest link)

Questions?

Perhaps....If the lamp still will not fire, most likely is a bad ballast. If you are electronically inclined,. first make sure the thermal cutoff on the lamphouse has not opened first and then check to make sure the 300 volt supply to the ballast is ok. If the fans are not running, and this is a combined ballast/power supply, most likely it is bad.

how many times? that will tell you what's wrong:

1x- lamp cover (close lamp cover)
2x- temperature problem (too hot. clean out and cool down)
3x- power problem (check power)
4x- fan problem (one or more fans not running)
6x- lamp fails to light (lamp or ballast problem)

test

Either lamp is failing (not covered under any warranty), or the ballast has failed. Or it may be a problem with the power supply, or even the fans... What is the picture next to the flashing light? If it's only the lamp light, then either lamp or ballast, if temp is flashing (the thermometer), it will be fans, temperature sensors, main board or power supply.

Here is the proceedure to replace the lamp and reset the lamp hours.
Lamp Replacement Procedure:
1. Press the POWER button to turn off the power.
2. Wait for about 1 minute until the cooling fan stops.
Note:
The lamp cooling fan will continue to operate for about 1
minute after the power is turned off. Do not unplug the AC
Cord from the outlet until the fan has stopped. Avoid
interrupting the power by using circuit breakers or switchable
power strips.
3. After the cooling fan has stopped, unplug the AC Cord from
the outlet.
Note:
Please wait more than one hour before replacing the lamp.
[ Forced cooling function ]
If you need to replace the lamp more urgently:
- The Projection display has a forced cooling feature.
After the POWER button is turned OFF, and during the
first minute of the normal cooling fan operation, press
the VOLUME UP button on the unit and CH UP key on
the remote at the same time for more than 5 seconds.
The cooling fan operates for about 10 minutes. (LAMP
LED will flash 5 times every 5 second and POWER LED
will flash red for 10 minutes.)
4. Remove the Front Cover Unit from the latches.
5. Turn the Knob to the left.
6. Pull the Lamp Cover out.
7. Loosen the Screw on the Lamp. Then, pull the Lamp.
Note:
Because the Lamp may still be hot, use caution when
handling.
8. Install the new Lamp, and tighten the Screw.
9. Install the Lamp Cover, and turn the Knob to the right.
10. Install the Front Cover Unit.
Lamp Time Reset Procedure:
Be sure to reset the Lamp time to "0" after replacing the new
Lamp.
1. Plug in the AC Cord, and turn on the power by pressing the
POWER button.
2. Press and hold the VOLUME DOWN button on the unit and
the SPLIT key on the remote together for over 5 seconds
in power on condition.
When the reset is finished, the display will indicate that the lamp hrs have been reset to 0 and the LAMP LED goes out.

Hi,

if the Lamp error and Temperature error lights are flashing red this means that there are two separate errors.

• A flashing lamp light means the lamp failed to ignite. It could be a lamp driver problem or lamp failure. Replace the lamp to resolve the issue. If the issue is not resolved, then service the projector.
• A flashing Temperature light signals a fan error. Turn the projector off and allow it to cool down. If the light is still flashing after the projector is turned back on, service the projector.

Goodluck..

does the lamp try to fire up
check lamphouse and fan filter safety switches