Sanyo 20 EZ no red showing

DaveyPocket

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The original problem with my monitor was that there was a red haze on the screen and some raster was visible (only red). If the red adjustments were turned down, it still showed. I tried disconnecting a few things to see what would happen (removing the transistor going to the red connection on the CRT, disconnecting the pin 8 (which controls red I believe)). After trying all of that and reconnecting what I had undone, red stopped showing up. Also the resistor going to pin 8 on the neckboard broke in half, I'm assuming this could be a problem?
Any other ideas?
 
yeah, the resistors are about as important as the transistors when it comes to color drive. lol

I was gonna suggest reflowing all the transistors cause that's what I had to on on my Z-whatever (it's not an EZV) in my PC-10. funny how my problem came about after I re-capped the damn thing.

I don't know any of the ratings on the resistors, I think there's manuals up on http://arcarc.xmission.com though.
 
The resistor could be part of the problem, or it could be a symptom of the shorted transistor. Test the transistor you removed with your meter and see if it's shorted. You can also swap that transistor into, say, the green circuit and see what that does. All three color circuits are identical, so you can swap parts between them to narrow down the problem.

-Ian
 
Okay, I swapped the transistor with the one on the blue circuit. Blue still works fine, red doesn't

I started tinkering with it more, now blue is out. Only green shows up. I'm going to take the whole thing apart (again) and see what I can do.
 
Did you replace the broken resistor?

Double check your work for solder bridges, cracks in the traces and cold solder joints.

-Ian
 
How "similar"? Do you mean of the same value with the same or greater wattage or just one that was about the same size, shape, and color? A John boat is similar to the Queen Mary and performs the same function but I don't recommend putting 1300 people in one...
 
Sorry, I'll describe more. Similar meaning same resistance, but different tolerance. The last band on the original resistor was silver, meaning +/- 10%. The one I replaced it with has a gold band for the last band, +/- 5%
Though I don't think that will make a difference.
 
Okay, so here's where I'm at

I got blue back. So, the only colors I'm getting are blue and green. When I flip the service switch to test mode (to get the horizontal line) and I have the "screen" adjustment on the flyback turned down a bit. I get a dim red line.
 
So, to test the red gun on I swapped the connections on the neckboard (I swapped red with blue)
So from my results, I believe it is the tube itself. It either seems that the red gun is weak or not working at all. Is there a way I can repair this? Or is it considered dead?
 
Hey guys!!!! I have the same problem! I have a Cr70 and it shows the tube to be great!

All I get is blue.
The transistors are not shorted, I bypassed the remote board and still the same thing.
I've even checked the transistors on the chassis. They are all not shorted

I am at a loss!
 

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Hey guys!!!! I have the same problem! I have a Cr70 and it shows the tube to be great!

All I get is blue.
The transistors are not shorted, I bypassed the remote board and still the same thing.
I've even checked the transistors on the chassis. They are all not shorted

I am at a loss!
 
Hey guys!!!! I have the same problem! I have a Cr70 and it shows the tube to be great!

All I get is blue.
The transistors are not shorted, I bypassed the remote board and still the same thing.
I've even checked the transistors on the chassis. They are all not shorted

I am at a loss!
did you bother with the adjustments on the neckboard? that looks like blue is turned all the way up.
 
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