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Dan
Dan, Master Tech and Repair Facility Trainer
Category: TV
Satisfied Customers: 7180
Experience:  USAF trained; A.A.S Electronics; A.A.S. Education; Currently teaching advanced troubleshooting and repair for the DoD.
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I HAVE SAMSUNG HLS7178 AND THE TV TURNS OFF AFTER A FEW SECONDS

This answer was rated:

I HAVE SAMSUNG HLS7178 AND THE TV TURNS OFF AFTER A FEW SECONDS WITH THE 3 BLINKING LIGHTS...I REPLACED THE LAMP, BALLAST, COLOR WHEEL, RESET LAMP HOURS AND TRIED BYPASSING THE TEMP SWITCH.. STILL THE SAME PROBLEM PERSISTS. ANY IDEA?

Dan T. :

Welcome to the site! I'm Dan. Please let me know when you've joined the chat.

Customer:

im here

Dan T. :

Hi. Welcome.

Customer:

thanks

Dan T. :

I'll need to know a little more about the symptoms...

Dan T. :

When you press the power button, does the color wheel spin?

Customer:

yes

Customer:

picture comes on and looks good

Dan T. :

How long until it shuts down?

Customer:

10 seconds 15 maybe

Customer:

i can barely get into the service screen then its off

Dan T. :

10-15 seconds after you get a picture?

Customer:

yes

Dan T. :

Where did you get the new parts?

Dan T. :

The lamp, specifically.

Customer:

discount merchant i believe

Customer:

phillips

Customer:

it came in a new housing as well

Dan T. :

And did that change the symptoms, at all?

Customer:

no

Customer:

i did the ballast, and then the lamp

Dan T. :

What's the part number on the ballast you put in?

Customer:

and i could hear the color wheel when it was turning off so i figured the bearing was going bad and replaced it

Customer:

let me check, one second

Dan T. :

OK.

Customer:

item # XXXXX

Dan T. :

OK. Same as what you pulled out?

Customer:

yes i compared them and even switched them back and forth

Customer:

same symptoms

Customer:

i appriciate your help by the way

Dan T. :

No problem at all. You might not like the diagnosis, though... ha.

Customer:

haha it is what it is

Dan T. :

But I've got to be honest with you... I really think you've got a bad DMD board in there.

Customer:

yea, i thought so

Dan T. :

Either that, or maybe a weak/failing power supply.

Customer:

it would act the same way if the dmd board was bad?

Customer:

yea, how do you test the power supply

Dan T. :

Well, the DMD can cause all sort of things. It's pretty much 4/4 on the list, but you've already replaced 1-3.

Dan T. :

Testing the power supply with these symptoms would be really tough. You're not getting a stable enough system, really, for any readings you take to be totally valid, in my opinion.

Customer:

dmd is the main mother board, or the small board by the projector behind the fan

Dan T. :

The good news, though, is you can get a used/refurbished DMD for your TV for about $50. With a warranty.

Customer:

o wow thats reasonable

Dan T. :

Small, rectangular board on the light engine.

Dan T. :

It holds the DLP chip.

Customer:

yes i have takin it out and put it back once already

Dan T. :

Yep, it's cheap because it won't come with the DLP chip. The chip is about $300, usually, but there's no reason to suspect the chip... just the circuit board.

Customer:

thinking the color wheel was in the light engine

Dan T. :

Ah.

Customer:

maybe i messed it up R and I it

Dan T. :

Maybe.

Dan T. :

Part number should be BP94-02269A, but I would take a good look at yours first.

Customer:

are there any sensors other than the the back door switch that would be doing this

Dan T. :

No. And if it was the door switch, you wouldn't be getting 15 seconds of video.

Dan T. :

Now that I think of it... have you checked the fans?

Dan T. :

Do they all spin freely when you power the TV on?

Customer:

here and there i get a check fan no 2 but i replaced it

Customer:

but not with a samsung part...like a computer fan with same voltage and wattage

Dan T. :

Hm. I don't recommend that.

Customer:

so its on and its not too hot in there....

Customer:

yea i was gunna try a new samsung fan, does it knw when its not a samsung fan

Customer:

and is there anyway to hard reset the system besides unplugging it

Dan T. :

The original fans tie into the TV's safety circuit with a feedback voltage.

Customer:

i c

Dan T. :

Hard/impossible for me to say if the PC fan will work.

Dan T. :

I would probably order a new fan and the DMD. They're inexpensive.

Customer:

yes i will do that

Dan T. :

And double/triple check the other fans, too, to make sure they're spinning freely.

Customer:

hope that will fix it

Customer:

theres only one other one

Dan T. :

I tap the motor/center of the fan with a screwdriver handle.

Customer:

correct?

Dan T. :

That helps, sometimes.

Customer:

ok

Dan T. :

I don't recall if there's 2 or 3, and can't get to my service data right now. Do you have the service manual?

Customer:

not with me

Customer:

ive reassembled this thing a million times by now, ive only seen the lamp fan and dmd board

Dan T. :

Do you have an exhaust fan pointing out of the back of the set?

Customer:

no theres a fan by the ballast that goes to the lamp and through a plastic grate thing that sits in front of the lamp and out the back

Dan T. :

OK.

Dan T. :

Well, fan and DMD... that's my advice.

Customer:

its not near a wall ive cleaned all the dust, dos the temp sensor go bad?

Dan T. :

Thermistor would be similar to the lamp door switch, in that, you wouldn't be getting video.

Customer:

ok, hopefully i can get it goin with those inexpensive parts

Customer:

ok

Dan T. :

ShopJimmy.com for the board.

Customer:

thanks

Dan T. :

Call them... don't use the site.

Dan T. :

My pleasure! Good luck!

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