Lou - N2MIY
Veteran Member
So for the past few weeks I have been working hard on repairing a trashpicked 42" plasma monitor. It's a 10 year old Pioneer PDP-424MV. It's not a TV, because it has no tuner, but it has tons of inputs on the side. I trashpicked this beast in the hopes that 1.) I could fix it and 2.) it could be a VR241 replacement. Will and I had been talking over the years about what could replace a VR241 in a simple manner. I actually bought a $30 RGB to VGA scan converter, but it needs clean composite synch and I did not build the LM1881 synch stripper yet. But then I saw this monitor in the trash about a month ago. So far 1.) I have fixed it and 2.) it looks like it might work as a VR241...
It was a bear to fix. One of four switching supplies on the y-sustain board was not working. The plasma engine is an NEC and there are no print sets anywhere for the engine. I had to reverse engineer the switching supply. Of course, it was a bad cap, but it sure took me a while to find it. It works now though. It does have bad screen burn also, but it was trashpicked. It was a little diversion from the RL02 emulator that had been burning me out....
So, this evening I hooked up the Rainbow. A while back I made this little box/cable affair for connecting both the VR241 and a VR201 to the Rainbow at the same time:
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14603
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14604
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14602
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14605
From the photos you can see there is a little box that breaks out the signals from the 15 pin monitor connector on the back of the Rainbow. The usual VR201 cable plugs into one side, where I also have a phone handset jack for the keyboard. The other side has a high density 15 pin connector. I have wired this connector with R,G,and, B drives wired to the usual VGA pins. No other pins are used (real VGA includes H and V synch lines, but the Ranibow does not have them, it's synch on green.) The little switch either connnects green drive or the monochrome drive to the VGA connector. (Remember, the Rainbow has two video subsystems, one monochrome, and one RGB. On the DEC VR241 cable, R, G, and monochrome as green get connected to the VR241. The real green drive is there, but never gets used in any dec cable.)
So, I use a standard VGA breakout cable to get R,Gs,B out to nice BNC connectors. The monitor has a slew of connectors, including R,G,B,H,V as BNC jacks. I wasn't sure if this plasma monitor would do synch on green, but it did!
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14606 (blurry, sorry)
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14600 (I always liked the game SCRAM!)
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14601 (I'm an engineer, so gotta have CAD)
The down side is that I cannot get all the horizontal scan lines displayed. It's a 480 line monitor, so it should work. I have to study the manual. I will report here if I figure out the settings.
My long term plan is to put this in the garage as a monitor for the VT240.
Keep your eyes peeled for people getting rid of 10 year old monitors...
Lou
It was a bear to fix. One of four switching supplies on the y-sustain board was not working. The plasma engine is an NEC and there are no print sets anywhere for the engine. I had to reverse engineer the switching supply. Of course, it was a bad cap, but it sure took me a while to find it. It works now though. It does have bad screen burn also, but it was trashpicked. It was a little diversion from the RL02 emulator that had been burning me out....
So, this evening I hooked up the Rainbow. A while back I made this little box/cable affair for connecting both the VR241 and a VR201 to the Rainbow at the same time:
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14603
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14604
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14602
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14605
From the photos you can see there is a little box that breaks out the signals from the 15 pin monitor connector on the back of the Rainbow. The usual VR201 cable plugs into one side, where I also have a phone handset jack for the keyboard. The other side has a high density 15 pin connector. I have wired this connector with R,G,and, B drives wired to the usual VGA pins. No other pins are used (real VGA includes H and V synch lines, but the Ranibow does not have them, it's synch on green.) The little switch either connnects green drive or the monochrome drive to the VGA connector. (Remember, the Rainbow has two video subsystems, one monochrome, and one RGB. On the DEC VR241 cable, R, G, and monochrome as green get connected to the VR241. The real green drive is there, but never gets used in any dec cable.)
So, I use a standard VGA breakout cable to get R,Gs,B out to nice BNC connectors. The monitor has a slew of connectors, including R,G,B,H,V as BNC jacks. I wasn't sure if this plasma monitor would do synch on green, but it did!
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14606 (blurry, sorry)
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14600 (I always liked the game SCRAM!)
http://www.vintage-computer.com/vcforum/album.php?albumid=204&attachmentid=14601 (I'm an engineer, so gotta have CAD)
The down side is that I cannot get all the horizontal scan lines displayed. It's a 480 line monitor, so it should work. I have to study the manual. I will report here if I figure out the settings.
My long term plan is to put this in the garage as a monitor for the VT240.
Keep your eyes peeled for people getting rid of 10 year old monitors...
Lou