House of the Dead 4 - 52" LG DLP Screen

EagleTG

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Working on a 52" DLP screen that's in a House of the Dead 4 cabinet. It is model number 52SX4D or 52SX4DUB.

It started with no image on the screen. I was getting a continuously blinking red light on the front of the unit (NOT the Lamp light, the standby light).

I took it apart, found that the power supply board had a few bad capacitors (via completely testing the board caps with an ESR meter). I've replaced those and done some other basic testing on the power supply (diodes, transistors, resistors, etc. all look good) now am getting a 5-blink code from the standby light. According to the service manual, this is normal standby mode. Yet I've got an input signal. I've also noticed that the fans do not stay running on the unit. The bulb never fires, yet I'm relatively certain the bulb is good. The TV is not showing any indications of lightbulb error codes, and the bulb is visually perfect (although I know this is not always the best way to test these bulbs).

I've tested the output of the ballast with an HV Probe, I get nothing from it. I'm assuming that it's due to other parts of the start-up not completing properly. I've read that there is a chain reaction start-up that occurs on these units, and if anything doesn't go right, it will terminate the boot process.

I was able to get the unit booting further, not quite sure how or why. In this case, the unit would show a solid red standby light and briefly blink the lamp light green. Then it would restart with the red standby light. The bulb still never fired in this mode. I was only able to get it to boot this far during one of my testing sessions.

As of now, I'm back to the solid red standby followed by 5 red blinks of this light. The process then restarts. The fans are back to running for about 3 seconds on initial boot before they stop. This REALLY looks like a power supply issue to me, but I can't seem to find it.

I had initially purchased another ballast, but have not installed it to try yet. I'm assuming it's not the problem at this point. I can't quite reach the 5V Lamp Enable plug to test it while in-operation (also, I'm not quite sure what the pin-out should read on this, as I can't seem to find that information in the service manual... even if I could reach either end of this plug).

I've tested the outputs of the power supply board and everything looks generally in-spec. I'm going to go through the outputs in more detail and will post the results now that I have the service manual (I was going by what was printed on the board).

I've done so much work and diagnostic on this thing, I'm sure I'm missing some info in this post.

I thought I'd post here and see if anyone had any better ideas. I will try over on FixYourDLP.com soon. I've also extensively Googled for information on DLP startup processes, and other common issues with this model and others. I've read a ton of information, but am open to suggestions on other things to try.

Thanks all!

Edit: I've also read that the color wheel needs to spin up before the bulb will fire. I've confirmed that the wheel is not seized, broken, or otherwise damaged. It does not spin during any of the boot process... however I've only been able to test that during the "3 second fan burst" boots.
 
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Light Engine?

The colorwheel has to spin first, as you know..
Check voltages to the DMD board..?
Any of the boards have any lit LEDS on them?

Maybe as simple as a bad fan,does one fan stop
seconds before the other fans have to check all fans.
Is any of them tight? if you see one spinning slow?
try helping it spin, see if it stays up then..

It may be better to just buy a light engine ,Where you at on this repair?
If its been {on} for atleast 3 years i would buy a lamp first!!
You may have collected error codes need to reset.
Even without lamp errors, they don't last more then 3-4yrs in the Home..
Good Luck!
 
The color wheel does not spin, or even pulse. Shows no sign of life. It is not seized, it spins freely.

I have checked the voltages coming out of the power supply (values of which are very nicely silk-screened onto the PCB). They all seem to check out. I have not tested at the DMD side of things yet.

There are no LED's lighting except on the front of the unit as mentioned in my original post.

All fans turn on (strong and proper) for the first few seconds of the unit being powered. Nothing appears seized, but I will double-check.

At this point, I've replaced the capacitors on the power supply board and tried a new (known good) ballast. I have yet to order a lamp, as it doesn't seem to be exhibiting any of the standard lamp failure symptoms. I also didn't get any HV pulse out of the ballast, so I'm assuming it never even tries to fire. I'd think I should see something trying to come out of the output of the ballast on an HV probe. This is where I assumed the problem was deeper.

So you are saying it could still be the lamp, even though the errors and symptoms don't seem to indicate that? I'm not adverse to trying that. It's definitely cheaper than the entire light engine.

The unit is from 2006, so it's about 5 years old. It has been in an arcade most of its life, but the arcade is not open every day.

Is there a way to pull more elaborate codes from the unit? I see that it has an RS232 for firmware upgrade. I was considering plugging a null modem/standard serial cable into it and seeing if it logs anything to the port during boot.

There is a lamp reset function that involves the remote on this unit. I think that process seems to require that you see the screen. Since I'm not getting that far, I'm guessing that has to be a later part of the process.

Thanks again for the assistance.
 
Lamp that Last 5 Years

They don't last that long in the Home!
Tip: Lamp may not come with Light engine..
Would you want a weak lamp after the Light engine
is replace, or any other part for that matter..
I understand your fears but from my experience i don't under estimate
the lamp..it doesn't have to implode to be bad,check the bottom
of the arc tube inside the lamp does it look swollen etc..

It's true the lamp may not be the direct problem at this time.
I would expect the all parts to start then stop after a few trys with the lamp.

Zenith/Lg uses a special service remote as a aid in repair..not easy to get a hold of
may not be needed if unpluging the set resets the error codes so you get fresh
error codes..Lamp time is different then, error code resetting...
The c/w needs voltage to it thru the DMD board..check ribbon to C/W
Need to remove sheild from dmd and test the voltages.

Do you have the service manual?
The Ballast doesnt work like a flyback that use's a rectifier in it
and you can measure DC at the anode..
Just for the record the ballast use a High voltage arc to light the arc tube..
can not measure with a dc high voltage probe.
But should be able to hear and see a flash on ballast board as it trys to start
the lamp atleast 3 times or more.
Sorry Upgrades don't fix sets for me..atleast dead sets.
Does the manual say what error 5 is?
 
Hi,

was this problem resolved? did a new lamp/light engine correct the problem?

very close to picking up a HOD4 Deluxe unit with failed DLP and wondering how much work/time/parts to get this unit going again for home use.

Thanks!
 
colorwheel?

Hi,

was this problem resolved? did a new lamp/light engine correct the problem?

very close to picking up a HOD4 Deluxe unit with failed DLP and wondering how much work/time/parts to get this unit going again for home use.

Thanks!


Hows the C/W Look?
ETG said his colorwheel look good.
Check yours..
Remove only the bracket just behind the monitor
so you can remove the back of monitor without
removing the monitor from the game..
Remove four screws to remove the cw
from the light engine..and the tape holding
the wires down,then remove the plug from the cw.
I started a new job and they gave me two dlps and both
the same model and both had broken colorwheel filter damaged.
Part# for filter #5230v00028e Happy hunting!
Is yours good??
 

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