Arcade Moniter Vsync problem

[epicfatigue]

Hello everyone.

First off wanna say thank you to everyone this forum is amazing and i have learned so much from reading other peoples experiences.

I have a mame cab (old karnov machine)

Asus Rampage formula x48
Intelxenon at 5.5ghz
Hyper X Ram 1044
Arcade VGA 3000
2TB HDD
Corsair 430 PSU
WG KV7000 19inch (see link below for manual)
http://www.wellsgardner.com/pdf/Spec/K7000.pdf



The problem i am having is i find that adjusting the pot gets the picture stable but only while pressure is applied the second i let go the monitor rolls like its 1969 or a get a solid white horizontal line!!!

I have resorted to wedging a little bit of cardboard in between the pots  to hold pressure on the vsync to keep it stable.

I am wondering is this one of the following

Dry or cracked solder joint
Damaged/faulty Pot
A pot in some serious need of lubrication
Possible cap kit?
Vertical collapse ?

I am going to discharge the monitor in a few days just wanted to find out what i am in for before i go into it and what i should know or what else i should be checking !

Also i have another problem thats very minor.  i find that the corners of the screen are missing (only when displaying windows screen etc dont seem to notice it during arcade games)
Its perfectly fitted vertical and horizontal but the edges are like they are folded backwards ill take a photo once i resolve the more important issue

Thanks everyone

[epicfatigue]

okay, so i believe it to be the pot or a dry solder joint.

Why?

Well if i rock VR5 (49-1027-00  040X0653-006 VR5  Resistor Control 200K )

The picture comes good, now where can i track down a replacement for one of these? is it possible to use another 200k pot?

Should i desolder it and clean it and put it back in or just outright replace it.

[lilshawn]

pots are pots except when they are audio.

try resoldering the pot and if it still flakes out grab a new 200k ohm pot and throw it in.

[epicfatigue]

pots are pots except when they are audio.

try resoldering the pot and if it still flakes out grab a new 200k ohm pot and throw it in.

So any 200k ohm pot should be fine?

could you give me an example i remember that there are 2 different types

[ed12]

hi
a pot is a pot
unless it is audio which is linear taper

ed

[epicfatigue]

Thanks everyone i will try re soldering it.

Quick question but,

If i discharge the monitor 3-4 times (yes its unplugged) can i leave the a-cap on ? as its just a quick job and cant be bothered pulling it off an on to save ware and tear on it.

Or can it continue to build voltage thanks.

[ed12]

hi
i can never recall removing the chassic to reflow a pot
the neckboard yes
the high voltage lead not that i can rem...

ed

[lilshawn]

hi
a pot is a pot
unless it is audio which is linear taper

ed

you mean logarithmic 

[Le Chuck]

A pot is a pot might be the worst piece of advice you could take away from this board.

Pots come in a variety of shapes, sizes, and properties even within a certain resistance. 

For example you can get 200 ohm rotary linear pots that are:

Single turn
Continuous turn
Multi-turn (1080 all the way to 3600 or greater)
Deflection less than 300 degrees

and come in a variety of styles such as panel mount and board mount with a huge range in actuator type and diameter. 

You can also get slide and thumb-wheel pots among others.  The best thing to so is look up the data sheet of the pot in question and find a replacement with similar qualities. 
 
Sure they would all likely work fine wired up properly to your board but having the correct part is always preferable to just an "any pot will do" approach. 

[epicfatigue]

A pot is a pot might be the worst piece of advice you could take away from this board.

Pots come in a variety of shapes, sizes, and properties even within a certain resistance. 

For example you can get 200 ohm rotary linear pots that are:

Single turn
Continuous turn
Multi-turn (1080 all the way to 3600 or greater)
Deflection less than 300 degrees

and come in a variety of styles such as panel mount and board mount with a huge range in actuator type and diameter. 

You can also get slide and thumb-wheel pots among others.  The best thing to so is look up the data sheet of the pot in question and find a replacement with similar qualities. 
 
Sure they would all likely work fine wired up properly to your board but having the correct part is always preferable to just an "any pot will do" approach. 

100% agree and thats the path i will be taking.
Thanks for pointing this out.


I have another off topic question.

I have been digging through bob roberts website... wow what a life saver this man is!.


I have a quick question about my VGA cable setup as it appears to be wrong and thats what is bending my picture, this i understand but there is something else that is bothering me.


I have not earthed my red blue green pins all to a common earth, however my monitor functions perfectly fine.
Is this recommended should i do this or should i leave it as its running fine?

EG. i do not have pins 6,7,8, connected yo pin 5

1 - Red
2 - Green
3 - Blue
4 - Not connected
5 - Ground
6 - Red Ground
7 - Green Ground
8 - Blue Ground
9 - Keyway (No pin)
10 - Sync Ground
11 - Not connected
12 - Not connected
13 - Horizontal Sync
14 - Verical Sync
15 - Not connected

[ed12]

hi
le chuck
a pot is a pot in the monitor game
the nick was asking a gen q
we answered...your reply is aboutsley off ground and or required
we could have gone tech here if u want ??
and i WILL post every possiable way..even up to and inculding a dac controlled pot..but back to the point it is a 200k pot
that need's reflow >cracked solder joint's or replacing
that simple..step down thk-u

A pot is a pot might be the worst piece of advice you could take away from this board.

Pots come in a variety of shapes, sizes, and properties even within a certain resistance. 

For example you can get 200 ohm rotary linear pots that are:

Single turn
Continuous turn
Multi-turn (1080 all the way to 3600 or greater)
Deflection less than 300 degrees

and come in a variety of styles such as panel mount and board mount with a huge range in actuator type and diameter. 

You can also get slide and thumb-wheel pots among others.  The best thing to so is look up the data sheet of the pot in question and find a replacement with similar qualities. 
 
Sure they would all likely work fine wired up properly to your board but having the correct part is always preferable to just an "any pot will do" approach. 

ed

[Le Chuck]

Ed, I wish I could read your gibberish.  Maybe someday.  Until then, keep doing what you do man.  Sorry for giving bad advice that was in now way actually bad.   

[epicfatigue]

:S settle down guys, everyones advice was equally helpful and greatly appreciated.

I am very new to all this and would love to learn as much as i can, i have always had a passion for arcade machines and electronics, i never imagined i would one day own my own machine.

Just wanna get it to be the best it can be.

Should i create a new post for my VGA connection ?