John's Arcade Forum - Classic Arcade and Pinball Collecting and Restoring Discussion Forum - RETRO MAME - Nintendo Vs Forum

Tech and Marketplace => I need help with my game! - Technical Discussion => Topic started by: kingdbag on February 05, 2017, 10:50:30 pm



Title: K7201 Issues
Post by: kingdbag on February 05, 2017, 10:50:30 pm
Had a monitor that was totally dead... replaced the flyback, hot and a cap kit. Now the tube comes on, but the screen is just red... with a little blue and green creeping in. I know I have to degauss it, but I honestly don't think that is going to fix it 100%. I tried adjusting every knob on the chassis and the picture just stays red. I don't see anything in any of the flow charts I've been looking at that help. I don't know where to go from here... any ideas?

I did see the attract mode working (I could see something move on the screen, but was hard to make out) at one point until I started tweaking knobs so I think the tube is getting picture correctly from the PCB. What's on the screen in the image I attached is just burn-in...

(https://forums.arcade-museum.com/attachment.php?attachmentid=298127&d=1486200469)


Title: Re: K7201 Issues
Post by: kingdbag on February 27, 2017, 11:19:04 pm
So after tweaking the monitor a little bit this is the best I can get the monitor to look... It is soooo blurry... when I try and adjust the focus on the flyback the screen just turns bright white if I turn it up too high. I messed with the convergence rings, degaussed the monitor, etc... and I just can't get it to look any better. Any ideas?  ???

Someone help me out!!!  ;D

(https://forums.arcade-museum.com/attachment.php?attachmentid=299391&d=1487036098)


Title: Re: K7201 Issues
Post by: BadMonkey on March 22, 2017, 02:16:38 pm
Can't see your pictures. I believe that you need to have the pictures hosted elsewhere and put the link to them here. But....that being said: are you aware of this monitor ever working?( asking in case the yoke, rings, tube or chassis has been replaced improperly.) assuming the game is playing blind, and your repairs have been made correctly, you may have a bad tube or you may want to check the neck board. Make sure the transistors on the board are good and that the socket is good. My checks go in order : power, connections, adjustments, components (caps, transistors, resistors) I had a metal oxide resistor go out on a 7000 series monitor. It is used as a type of fuse. It went out due to bad transistors.


Title: Re: K7201 Issues
Post by: BadMonkey on March 22, 2017, 02:43:18 pm
Also: I believe some med res monitors had jumpers (or a jumper bundle) on them to use as standard res. Not sure if yours is one or not. Something to look into. I'm not in my shop ATM but I'll look it up when I can.