[HELP] NEC NP400 Mod problem

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deliquenme
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Re: [HELP] NEC NP400 Mod problem

Message par deliquenme » 24 janv. 2014, 01:18

Hello, sorry for writing in english but if I would write in french I don't think you would understand me.

After finding this great forum I got two videoprojectors with dead lamps hopping I can mod them, the first was a Hitachi RS CP55 that I managed to MOD and put in a Xenon 55W and works a treat but the other is a NEC NP400 that gives me a hard time.

The problem is that I've shorted the two wires that go to the optocoupler for the Lamp OK signal and I know that is the right one because there are 3 optocouplers, two have the emmiter and collector to the ballast and the other to the motherboard, but I still get the Lamp error, I've set to close all the optocouplers and the same Lamp Error, on the motherboard I have 5 fan connectors, 2 Temp sensors, 1 speaker, the ballast connector, and the power plug. I understand that some VP's have a light sensor but for a light sensor to be there it would need a wire and connector, there is nothing else on my motherboard.

Any ideeas?
Thank you!

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oreo
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Re: [HELP] NEC NP400 Mod problem

Message par oreo » 24 janv. 2014, 11:24

Hi, where do you have apply the shunt? on the ballast or on the motherboard?
Could you please show us a photo of your shunt?

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Re: [HELP] NEC NP400 Mod problem

Message par deliquenme » 24 janv. 2014, 15:06

Here are the images, in the first one I've shunted the wires on the connector wires and in the first I've shunted the legs of the optocoupler, I've marked with yellow lines the traces that go to the connector. So pin 1 and 2 are the emmiter and collector.

Image

Image


I've e-mailed NEC but they would not provide a service manual.

Thank you for trying to help and I hope I can figure it out.

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Re: [HELP] NEC NP400 Mod problem

Message par deliquenme » 24 janv. 2014, 18:02

I searched the internet for similar problems and found that some VP's use a serial communication for the lamp OK signal, and found a single chip that I can't find any data for. The signal out opto seams to connect to pins 2 and 12 on that chip but I could be wrong, I posted a picture of the chip.

If it's a serial com device I don't think I can mod the VP without a service manual.

Image

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Re: [HELP] NEC NP400 Mod problem

Message par oreo » 24 janv. 2014, 18:22

If you are sure to have follow the good wire from the opto on the ballast to the motherboard, it certainly use a serial communication or thing on that way...i'll seek about it.
By chance, for my own mod i've just welded the opto wire on a earth of the motherboard, have you tried that?

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Re: [HELP] NEC NP400 Mod problem

Message par deliquenme » 24 janv. 2014, 18:32

Yes I've tried that too, and the wierd thing is, pin1 is 3V, pin2 is GND but is not the same GND as the screw GND. And if I messure the Pin1 and Pin2 I get 3V, and if I messure Pin1 and Screw GND I get nothing.

Image

I will take the motherboard out and look for that same chip that is on the ballast, and follow it to Pin 1 and put it to GND and see what happens.

If only I could find a service manual for NEC NP seriesd projectors...

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Re: [HELP] NEC NP400 Mod problem

Message par oreo » 24 janv. 2014, 19:03

Apparently Oliv49 had a similar problem 5 years ago with a Osram ballast (your's osram too?) >http://www.homecinema-fr.com/forum/vide ... 16333.html < there they'd explored ways to regulate the concern without victory, but maybe you'll find some interrestings infos (the language what seems to pose a problem to you must be USART >http://fr.wikipedia.org/wiki/UART (in french sorry but i'm sure you'll find infos in english about it).

Another trick to try, as explained on the 1st link, is to add an interruptor to your shunt, and apply the shunt a few milliseconds after have putted on your video projector.

Don't hesitate to send a mail to Oliv, he's a nice guy and a good teacher ;) and do not worry you, others answers will come from those which encountered the same problem.

PS: All what I found about your VP:
- User's manual >http://www.mccneb.edu/techroom/document ... manual.pdf...useless

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Re: [HELP] NEC NP400 Mod problem

Message par deliquenme » 24 janv. 2014, 19:15

Thank you, will check it out, my ballast is USHIO.

As I said I've looked at the motherboard on both sides and no luck, there is no chip that looks like the one on the ballast, I've put some pictures with all the chips I have on the motherboard.

Image
Image
Image
Image
Image
Image

And allot like this one
Image

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Re: [HELP] NEC NP400 Mod problem

Message par oreo » 24 janv. 2014, 19:28

Sorry, I can't help you with those... little things, it's kingon to me, but i'm sure a lot of people here speak klingon very well ;-)

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Re: [HELP] NEC NP400 Mod problem

Message par oreo » 24 janv. 2014, 19:53

And, I've just thunk, of course you paid attention to little contactors of the closing of the trap door? Did you?
There may be 2 others, one behind the trap door filters , and one on the small circuit of the receiver of remote control of the front face.

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