Zenith X-Box Screen Voltage Question

GonzoMPM-1 · Post by **GonzoMPM-1** » Thu Jul 03, 2008 7:12 pm

OK, am I on crack here?

The a/c adapter that came with the screen I'm using for a project says it is putting out over 12 volts.

OK, fine. That's not what it says, but whatever.

But here's where I have a question: I look at the internal regulator and IT is putting out 11 volts. Not 7.2 - 8v which is what I would think this device needs.

What the hell is going on here. Is it dangerous hitting this sucker with 11 volts, or is the regulator on the main Zenith board taking it down to 7.2 and 5v anyway.

If the later is the case, I presume that they're throwing higher voltage at the thing because of the drop out in their regulator. Anyway, what voltage can I feed this board directly WITHOUT using that stupid power supply daughter board?

Has anyone done so?

Chapel · Post by **Chapel** » Thu Jul 03, 2008 7:25 pm

WITH the daughter board I am feeding it 7.4V and the screen works pretty well (except for the backlight which I apparently broke

and is scheduled for a LED mod). Others on this forum have commented that not using the daughter board reduces the quality of the output.

As for your possible drug usage, urine tests are a better way to find out.

GonzoMPM-1 · Post by **GonzoMPM-1** » Thu Jul 03, 2008 8:26 pm

Chapel wrote:WITH the daughter board I am feeding it 7.4V and the screen works pretty well (except for the backlight which I apparently broke and is scheduled for a LED mod). Others on this forum have commented that not using the daughter board reduces the quality of the output.

As for your possible drug usage, urine tests are a better way to find out.

Do you mean that the daughter board you are using is putting out 7.4 v? 'Cause mine puts out 11v

Chapel · Post by **Chapel** » Thu Jul 03, 2008 9:57 pm

GonzoMPM-1 wrote:
Chapel wrote:WITH the daughter board I am feeding it 7.4V and the screen works pretty well (except for the backlight which I apparently broke and is scheduled for a LED mod). Others on this forum have commented that not using the daughter board reduces the quality of the output.

As for your possible drug usage, urine tests are a better way to find out.
Do you mean that the daughter board you are using is putting out 7.4 v? 'Cause mine puts out 11v

I don't know what it is putting out, but the screen works when hooked up directly to a 7.4v Li-ion battery with the daughter board.

GonzoMPM-1 · Post by **GonzoMPM-1** » Fri Jul 04, 2008 11:26 am

Chapel wrote:
GonzoMPM-1 wrote:
Chapel wrote:WITH the daughter board I am feeding it 7.4V and the screen works pretty well (except for the backlight which I apparently broke and is scheduled for a LED mod). Others on this forum have commented that not using the daughter board reduces the quality of the output.

As for your possible drug usage, urine tests are a better way to find out.
Do you mean that the daughter board you are using is putting out 7.4 v? 'Cause mine puts out 11v
I don't know what it is putting out, but the screen works when hooked up directly to a 7.4v Li-ion battery with the daughter board.

Does yours work _without_ the extra daughter board? Its kind of big, clunky, and hot with that voltage regulator.

dragonball345 · Post by **dragonball345** » Fri Jul 04, 2008 3:18 pm

The daughter board probably just drops the 11 volts fed into it down to 7.2 volts which then directly powers the screen quite a few power adapters I've seen and if your screen gets its power directly from the xbox I think use 12 volts.

GonzoMPM-1 · Post by **GonzoMPM-1** » Fri Jul 04, 2008 4:01 pm

dragonball345 wrote:The daughter board probably just drops the 11 volts fed into it down to 7.2 volts which then directly powers the screen quite a few power adapters I've seen and if your screen gets its power directly from the xbox I think use 12 volts.

That's my point. When fed 12 volts, the daughter board is NOT producing 7.2 volts.

It is producing 11 volts.

Chapel · Post by **Chapel** » Fri Jul 04, 2008 6:52 pm

GonzoMPM-1 wrote:
Chapel wrote:
GonzoMPM-1 wrote:
Chapel wrote:WITH the daughter board I am feeding it 7.4V and the screen works pretty well (except for the backlight which I apparently broke and is scheduled for a LED mod). Others on this forum have commented that not using the daughter board reduces the quality of the output.

As for your possible drug usage, urine tests are a better way to find out.
Do you mean that the daughter board you are using is putting out 7.4 v? 'Cause mine puts out 11v
I don't know what it is putting out, but the screen works when hooked up directly to a 7.4v Li-ion battery with the daughter board.
Does yours work _without_ the extra daughter board? Its kind of big, clunky, and hot with that voltage regulator.

I would be too worried to try it without the daughter board as it may fry something. I figure that the daughter board serves some purpose and that it is better to err on the side of caution.

superdeformed · Post by **superdeformed** » Fri Jul 04, 2008 9:23 pm

The LCD driver on the screen board is fed straight off of the 7.5V input, so you definitely do not want to power it without something to regulate that voltage. I'm not familiar with the x-box version of the screen, but the gamecube and PS2 versions have a really dirty regulator that relied on the load to get the right voltage, so it may be the same case here as well. Are you checking the voltage of the daughter board while it's plugged in to the screen? If you are, I suggest not using it and finding an alternate method to power it (which you seem to want to do anyway, anything that puts out about 7-7.5V that can handle the current should work). If you're checking it with nothing hooked up to it, then try putting a 100 ohm or so resistor across the output of the regulator and checking it again. The resistor should be rated for at least 1 watt, so if you don't have anything that big just connect a bunch of 1/4W (standard size that radioshack carries) resistors in series.