how to test a dlp ballast?

[mattstolte]

can anyone tell me how to do this?

[tom66]

Re: how to test a dlp ballast?

Magnetic or electronic? For magnetic it should be a short circuit. Need an LCR meter to confirm.

[mattstolte]

Re: how to test a dlp ballast?

The ballast is the thing the bulb plugs into right? Is there a way i can just put meter progs in there and press power on tv and watch for voltage?

[goontron]

Re: how to test a dlp ballast?

The ballast is the thing the bulb plugs into right? Is there a way i can just put meter progs in there and press power on tv and watch for voltage?

if you want to plug your meter in and watch for flames as your meter explodes then yes.

[Kilroys]

Re: how to test a dlp ballast?

First, is the door lamp switch closed ?
There should be about 300V to the ballast and
about 5V lamp_enable signal to make the lamp lit.
Could you hear the ballast arcing ?
Could you hear the color weel spinning ?
No spinning, no lamp_enable signal.

[RCA2000]

Re: how to test a dlp ballast?

Agree with what was said here. Nealy all sets I have seen--DLP or LCD or even LCOS or DILA--ALL of those with a vapor l;amp--have electronic ballasts. ONE foreign-made one had a magnetic ballast and an "ignitor" module off of it.

You CANNOT safely test the output to the bulb. During 'ignition" that voltage surges to at least 10Kv or higher !! Once a proper arc is established-a MUCH lower voltage--usually under 100 volts at substantial current levels--is then sourced to the bulb--to keep it running.

To properly test one--you need a proper load. A KNOWN good bulb. Then you could tell if it was firing the bulb and then maintaining it. You would also want to know if the input voltage to the ballast--usually 300-385 volts DC, is correct. Some ballasts get the AC from the main PS and then convert it on-board. Also--you need to know if the "lamp on" command is getting to the ballast.

But like said above--if the Color wheel is to coming up to proper speed--the ballast will NOT receive its' "on" command..and no lamp. Check to see if this is ok. And if you see--and/or hear--a "ticking" or "snapping" noise--from the bulb-- after turn on--the ballast is working--and you likely ned a new bulb.

[RCA2000]

Re: how to test a dlp ballast?

I forgot to add--I have seen only a FEW bad ballasts in tv sets..in ALL of my repair years. It is almost ALWAYS some other problem.

[mattstolte]

Re: how to test a dlp ballast?

First, is the door lamp switch closed ?
There should be about 300V to the ballast and
about 5V lamp_enable signal to make the lamp lit.
Could you hear the ballast arcing ?
Could you hear the color weel spinning ?
No spinning, no lamp_enable signal.

Im new to dlp so I don't know what sounds I'm looking for but when I got it I went to power it on and screen came on and I seen all the fuzz on picture but no light up on screen and green light was blinking lamp and TV went out. So I changed bulb and it still does that. Saying lamp

[mmartell]

Re: how to test a dlp ballast?

If you KNOW the lamp is good then could be your colour wheel. Remove it and see if it spins freely or is binding even slightly.

[R_J]

Re: how to test a dlp ballast?

Whats the Make and Model number??? How did you see a (fuzz) picture if the lamp did'nt light? The color wheel must spin up before the lamp will light.

[mattstolte]

Re: how to test a dlp ballast?

whats the make and model number??? How did you see a (fuzz) picture if the lamp did'nt light? The color wheel must spin up before the lamp will light.

samsung hls4266wx/xaa and once i got it i turned it on and i seen fuzz on screen, tv was dark and lamp was not on. So it turned on for 1 sec and then turned right back off so i thought it was lamp and green lamp light was flashing so i thought for sure thats what it was, well it still did same thing when i put new malp in.

[R_J]

Re: how to test a dlp ballast?

How could you see anything on the screen if the lamp did not light? What the @%*&! is Fuzz?

[Agent24]

Re: how to test a dlp ballast?

What the @%*&! is Fuzz?

A horribly blurry picture?