CurtPalme.com Home Theater Forum

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Hi guys,

I just recently got some spare time to play around with the Ampro, I changed out the green tube after my old green tube started shorting and I am not sure if it did any other damage to the pj.

I plugged in an extron unit to provide a signal with a dot pattern as I was going to do the astig. The red and blue tube are fine and produce a dot pattern the green tube has no dots just a large raster pattern covering the tube face it seems as the attached jpeg shows.

I changed out the crt pc board and still had the same problem.

I have done something wrong or something is damaged, any ideas?

Thanks again.

**Curt Palme** · Posted: Mon Nov 28, 2016 2:29 am Post subject:

Swap the 2 pin video cable between tubes, it llooks like you have no video going to the neck board. Maybe the tube is open? Is the cutoff button pushed on the remote turning the tube off?

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Is the new green tube the exact same kind as the original?

If not, what is the type of the original (full model number) and what is the type of the new one?

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Hi guys,

I changed out the 2 pin video cable between tubes and the green came on! thanks Curt, however the red went off so I assume that the rgb input boards green output is shot?

I also saw I have a couple of red lights on my cpu board even with the pj off not sure what this means. I posted a picture of the rgb board.

Thanks for the suggestions CM.

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

cr43 cr44 leds?

power supplies have been effected by the discharge from the other green?

**Curt Palme** · Posted: Tue Nov 29, 2016 2:13 am Post subject:

I'm not in front of the manual, but I'm sure that's not the problem. I suspect the RGB board. You're sure the red tube isn't turned off via the remote? Also check the CPU battery. It should be 3 volts. Anything under 3 volts should be replaced. The only reason I say check that the red cutoff isn't turned on is because I've never had a bad RGB board in a late model Ampro. IF the battery is low, the remote and internal memory settings can glitch to whatever value it wants.

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Thanks Curt I will try and measure the battery and then see where we go from there.

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

I had a spare rgb board from my old 4300 and changed it out with the same results, so no its not the board as you said Curt.

**Curt Palme** · Posted: Sun Apr 16, 2017 7:27 pm Post subject:

Are you sure the blue tube video isn't simply turned off on the remote? Is the 2 pin video connector turned around the wrong way?

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Hey Curt, I was just implying you were correct and its not the RGB board, I had thought it was the neck card tube rgb etc but not so. ANyway the hvps is restarting all the time and it wont come on so I think its time to give up.

Had a lot of good years and watched a lot of movies so no regrets.

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Because you did not answer the question, let me ask it again. What is the exact model number of the ORIGINAL green tube and what is the exact model number of the NEW green tube?

I'm asking because not all green tubes are wired the same. Some have G2 wired to pin 2, others have G2 wired to pin 6, and in
some projectors one type won't work without a minor modification.

**Curt Palme** · Posted: Sun Apr 16, 2017 11:31 pm Post subject:

Yeah, the HVPS are a PITA for sure. I might have one, but have dumped my last Ampro, so I have no way to test it, although I don't keep dead parts here.

Cheers!

**AnalogRocks** · Posted: Mon Apr 17, 2017 12:09 am Post subject: Re: Hey

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

As I remember, AmPro neck boards don't use very many parts that are expensive and at least when they were being made, they were mostly pretty common parts as well. Which just means that if the problem is on the neck board, it is almost surely repairable.

Some parts are not quite so easy to come by today, like those Ohmite thick film resistor hybrids, but generally the only way those
get damaged is by mishandling. And if you do need some I'm sure you can come up with spare boards to draw parts from.

There was someone offering a 4600 on ebay recently. I think it had no takers. I was interested in buying it myself, but the tubes showed wear and only the tubes were what I was after. I don't think the unit sold. It may still be on ebay.

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Hi guys,

I dont give up easy haha,

I changed out the a while ago and the lvps I got them from Curt, my problem I am based in the UK getting parts shipped to me now is going to be hard and I no longer have time to maintain the aircraft carrier. WIth the pound going down currency wise its more expensive as well.

CM regarding the tubes, everything was ripped off this tube information wise. I used the neckboard it came with, this tube is originally from my 4300 and I am sure it was a different pinout. SO maybe this is causing havoc or maybe the arcing damaged the hvps etc, I am not sure. Saying that when I changed out the wires as CUrt suggested to the RGB board the green came on just fine. I thought it was then the green output on the rgb board, so I switched out the rgb board as I have some spare parts but no such luck. I have also changed out the neck boards prior to this.

As I said I have watched hundreds of films and the tubes are still in great shape and everyone who watched movies on the ampro was blown away as they had never seen a crt projector before except in pubs and they were not great.

I modified my ampro quite a bit, six pole magnets on the tubes, coloured c elements and HD 10F lenses and new glycol when I got it. The best investment was the glycol as the ampro tubes looked yellow originally, coloured c elements, then the lenses then the six pole for me anyway.

A huge thank you to all of you guys who have helped me over the years, you are an amazing group of people!

**Curt Palme** · Posted: Mon Apr 17, 2017 2:12 pm Post subject:

This really shouldn't be hard to fix. Did you try toggling the green tube on and off? Same with the red and blue?

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

The 4300 and the 4600 should both be using P19LCP tubes. So if you have more spare tubes in your 4300, you can borrow one and use it to test the 4600's video circuits with it. This will mean that you are running short a green tube and have two reds or two blues installed, but it will allow you to figure out if the problem is in the projector or if the problem is in the green tube.