Sanyo EZV fold over issue

Zork2

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Not sure if this should go here in the monitor forum or not?
But here goes, I recently rebuilt my EZV. Picture looks GREAT with the original Donkey Kong 3 board in place, see pic. When I try to run my Donkey Kong board on it, I keep getting a bad fold over issue. I'm guessing this is a DK board issue?? NOT a monitor issue? And if it IS a DK board issue, what is my most likely cause? A bad VR2 Horizonal Pot? It is measuring 11Mohms?
 

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Could be a bad pot. There are pots on the board and monitor. Sometimes its easy to tell which are bad by tapping on them. Sometimes the white video cable between the monitor and board could be suspect. I would get the same thing if it wasn't plugged in properly at the board.
 
WEll my DK board is hooked up VIA the Jamma style connector? And like I said, my DK3 board works FINE using the same cables???
 
He is referring to the pots on the DK PCB. Same thing I told you at BYOAC, but I'm not sure if you saw it. Have you tried adjusting those pots on the DK PCB yet?
 
Thats not foldover. It looks like a sync issue. Try adjusting the Hhold pot on the chassis when the DK board is hooked up. Sometimes the output freq isn't exactly the same from board to board.
 
Yeah I tried adjusting the pots on the DK board. It does not help, no matter what combination I try. In fact, I can't tell, but it doesn't appear that VR2 does anything? I just checked the resistance on it, it is reading 11.5Mohms, and it does not adjust? That can't be right huh?

"Try adjusting the Hhold pot on the chassis when the DK board is hooked up"

I did this, but it doesn't want to sync up?? The pic I sent, is about as good as it gets??

It's been tough figuring this out as I have been dealing with mulitple issues! Not sure of anything anymore! HA! But I do think my monitor is solid now??

If that VR2 pot on the DK board was shot, would that cuase it to NOT sync up?
 
If the pot doesn't do anything, then it's got to be messed up. I replaced my VR1 and VR2 30k PCB pots with Bob Roberts 50k pots. My 4 board set sets says either types will work. The pots would be my first suspect, and are very easily replaced.
 
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Yeah I'm guessing 11MEGAOhms is not good! So Bob carries those? 50kohms? Ok good I'll check it out.
So if that pot was bad, would that board not syncing up be the result? Must have been damaged in shipping?
I wonder if I could steal the one off my DK3 board in the mean time? Anyone know if that would work? I wonder if it the same 50K pot? The number on the pot is different?
 
V-hold does nothing? I can get it to about what you see in the pic.....
 
Check the pot on the board and make sure it is not broken, and if it is not broken remove it and test it out of the circuit.
 
Well it doesn't LOOK broken, but that being said it is reading 11Mohms, and adjusting it does nothing, I'll pull it and check it out of the board....
 
Well, just pulled it, and I miss read, it is VR1, NOT VR2. After it was pulled it readed OL, open, so dialing would occationally get it to register, in the Mohm range..... VR1 is a 30K pot on DK3 by measuring it, I'm going to try and swap it out, and see if it cures my issue...
 
WAHOOOOOOOOO!!!!!
Worked like a champ!! Here is the proof! Thanks for helping me through guys!
Next time I place an order with Bob, I'll grab a 30K pot!
 

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I have two problems that I cant remember how to fix. Monitor is the (nintendo) SANYO EZV, problem #1, No vertical hold. rolls fast and slow as I adjust the v-hold knob, but it never "locks". Picture not scrambled, just cant stop it from rolling. Problem #2, Which caps do I need to replace to fix the famous 1" rollover on the top (vertical) of the screen? Seem to remember it was two caps. Cap kit already installed by other tech. Just trying to remember which two it was.

I do not have a flowchart for this monitor in my randy fromms big book (or its missing). DOKERT, I saw you posted something like this somewhere in this or another forum but I could not find it. Could you link to it if its still available.
 
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