2tank
03-14-2010, 08:43 AM
It has been brought to my attention that this article would best fit in here. I've been in the process of fixing 2 Nec GP-5000 9 inch CRT projectors. Both power supplies have some trouble. One power supply caught fire, and I had to go through and replace the cooked and crispy components. The other is experiencing some voltage problems. I am trying to adjust both supplies to actually get both projectors running. I have seen the picture on one of them before the power supply went totally bad, and enjoyed it very much. Newer digital projectors just can’t capture the color hues and black levels as good as a properly set-up CRT set.
I originally outlined this project in the "General Off Topic Forums" section. I will copy and paste the information from that over here if anybody wants to read the “long version.”
The “Long version:”
Post 1:
03-07-2010, 07:52 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
Nec GP-5000 Projectors, weekend project
________________________________________
I'm new here. I've been dealing with electronics for a few years now, and I keep obtaining more and more projects. I collect vintage stereo equipment, mostly Pioneer SPEC equipment, and I have recently acquired some projectors to make a theater/stereo room. My current project involves 2 Nec GP-5000 CRT projectors. I am in the process of getting them both running well. One needs minor adjustments to become "friendlier" and the other one's power supply needs adjusted. I will be asking how to adjust the power supply. I have the user manual, service manual, remotes, and cords. I do not have a schematic, nor can I find one. I have access to some laboratory/testing equipment when that time comes. I powered this projector up and tested the voltages on the various outputs. Some were close to where they needed to be, and others were far off. I want to know if anybody has a clue about how to adjust the power supply (I think it is a Rubycon RPS-02 if I remember correctly). I opened it up and there are some adjustment pots, but I don't have the schematic that tells me what they adjust. I'll post some pictures as soon as I figure out how to do that.
Post 2:
03-07-2010, 08:06 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
Picture of a GP-5000
________________________________________
This is a picture of one of the projectors from last year. I got this one working, but it is tempermental about when it decides to work.
Attached Thumbnails
Post 3:
03-09-2010, 09:12 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
New Plans
________________________________________
Tomorrow, I will be going to the lab to work on the projector with the bad power supply. If anybody has a schematic or an idea about how to adjust the power supply, please post some information.
Right now, my plan is to hook up some voltage testers and adjust slowly and document changes. It will probably be a slow and tedious process, but it's better than having it catch on fire again. I've fixed the circuit board and replaced a diode, resistor, and high voltage transistor. I will include some "before" pictures of the board and components. I didn't have my camera with me when I fixed these, so when I'm working on it tomorrow I'll take some pictures of my handy work.
Post 4:
03-09-2010, 09:17 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
"Before" pictures of power supply board
________________________________________
These are some "before" pictures of the power supply board I fixed.
Attached Thumbnails
Post 5:
03-10-2010, 07:57 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
After Lab
________________________________________
I was in the lab for an hour today. I adjusted all five pots with no luck. I did not see an appreciable change in voltages anywhere. I am still unsure about what the problem is. I have taken the power supply from the one that works on good days and I will swap them sometime soon. Here are some various pictures. Some are from the new parts on the board, and others are of the projector, and others still are from the power supply. If anybody wants to post an idea of how I can adjust it and have it work, let me know. If you know anything about the Rubycon power supplies, that would also be helpful. I may consider designing a completely new unit. I have read the standard ones are unreliable.
Attached Thumbnails
Post 6:
03-10-2010, 10:48 PM
bgadow
Me & My TV Join Date: Oct 2003
Location: Federalsburg, MD
Posts: 3,177
I hope somebody can chime in...I'm sure somebody on here is familiar with these. Might get more attention in the "rectangular" section? Anyway, welcome!
__________________
Bryan
Post 7:
03-14-2010, 09:33 AM
2tank
AK Member Join Date: Mar 2010
Posts: 6
Thanks, I'll post a new version of this in the "Rectangular" section.
This is the end of the "Long version."
I'm still looking for a schematic or information about how to achieve the proper voltages in these Rubycon RPS-02 power supplies. If anybody knows anything about them, let me know, any information is greatly appreciated. When you're in complete darkness, even a single photon of light increases brightness by an infinite ratio.
I'll have to repost the pictures; they did not copy with the text.
I originally outlined this project in the "General Off Topic Forums" section. I will copy and paste the information from that over here if anybody wants to read the “long version.”
The “Long version:”
Post 1:
03-07-2010, 07:52 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
Nec GP-5000 Projectors, weekend project
________________________________________
I'm new here. I've been dealing with electronics for a few years now, and I keep obtaining more and more projects. I collect vintage stereo equipment, mostly Pioneer SPEC equipment, and I have recently acquired some projectors to make a theater/stereo room. My current project involves 2 Nec GP-5000 CRT projectors. I am in the process of getting them both running well. One needs minor adjustments to become "friendlier" and the other one's power supply needs adjusted. I will be asking how to adjust the power supply. I have the user manual, service manual, remotes, and cords. I do not have a schematic, nor can I find one. I have access to some laboratory/testing equipment when that time comes. I powered this projector up and tested the voltages on the various outputs. Some were close to where they needed to be, and others were far off. I want to know if anybody has a clue about how to adjust the power supply (I think it is a Rubycon RPS-02 if I remember correctly). I opened it up and there are some adjustment pots, but I don't have the schematic that tells me what they adjust. I'll post some pictures as soon as I figure out how to do that.
Post 2:
03-07-2010, 08:06 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
Picture of a GP-5000
________________________________________
This is a picture of one of the projectors from last year. I got this one working, but it is tempermental about when it decides to work.
Attached Thumbnails
Post 3:
03-09-2010, 09:12 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
New Plans
________________________________________
Tomorrow, I will be going to the lab to work on the projector with the bad power supply. If anybody has a schematic or an idea about how to adjust the power supply, please post some information.
Right now, my plan is to hook up some voltage testers and adjust slowly and document changes. It will probably be a slow and tedious process, but it's better than having it catch on fire again. I've fixed the circuit board and replaced a diode, resistor, and high voltage transistor. I will include some "before" pictures of the board and components. I didn't have my camera with me when I fixed these, so when I'm working on it tomorrow I'll take some pictures of my handy work.
Post 4:
03-09-2010, 09:17 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
"Before" pictures of power supply board
________________________________________
These are some "before" pictures of the power supply board I fixed.
Attached Thumbnails
Post 5:
03-10-2010, 07:57 PM
2tank
AK Member Join Date: Mar 2010
Posts: 5
After Lab
________________________________________
I was in the lab for an hour today. I adjusted all five pots with no luck. I did not see an appreciable change in voltages anywhere. I am still unsure about what the problem is. I have taken the power supply from the one that works on good days and I will swap them sometime soon. Here are some various pictures. Some are from the new parts on the board, and others are of the projector, and others still are from the power supply. If anybody wants to post an idea of how I can adjust it and have it work, let me know. If you know anything about the Rubycon power supplies, that would also be helpful. I may consider designing a completely new unit. I have read the standard ones are unreliable.
Attached Thumbnails
Post 6:
03-10-2010, 10:48 PM
bgadow
Me & My TV Join Date: Oct 2003
Location: Federalsburg, MD
Posts: 3,177
I hope somebody can chime in...I'm sure somebody on here is familiar with these. Might get more attention in the "rectangular" section? Anyway, welcome!
__________________
Bryan
Post 7:
03-14-2010, 09:33 AM
2tank
AK Member Join Date: Mar 2010
Posts: 6
Thanks, I'll post a new version of this in the "Rectangular" section.
This is the end of the "Long version."
I'm still looking for a schematic or information about how to achieve the proper voltages in these Rubycon RPS-02 power supplies. If anybody knows anything about them, let me know, any information is greatly appreciated. When you're in complete darkness, even a single photon of light increases brightness by an infinite ratio.
I'll have to repost the pictures; they did not copy with the text.