scrolling bars nanao monitor

[borg07of09]

nanao ms-2932s

there are two 2 inch bars scolling from the bottom to the top.

adjusted settings on back of monitor:
     1)bars gets lighter or darker depending on which settings i touch

setting brightness darker makes bar disappear (but can still see it) and lighter makes bar easier to see

i tried to take many pictures of it but pictures cant duplicate what problem is (imagine looking at the screen through picture camera or moving camera and you can see the scrolling bar.  it kind of looks like that)

im not sure what to do.  can someone please help me?  thanks.

[grantspain]

it sounds like an electrolitic cap fault somewhere on the chassis,i have these models in manx tt and i have had a similar fault-i changed the electrolitic on the neck card(there

[Kevin Mullins]

I'll second the vote for it being an electrolytic capacitor problem....

[borg07of09]

thanks guys.  where could i get this part?  what is the part number?  do you have a picture of it so i can see what part i need to replace?

i really appreciate the help.

[grantspain]

what are you running the monitor from by the way(arcade or mame)-the capacitor i refer to is the only one on the neck card(small cylinder thing-probably says 250v 47uf or 22uf)-i can get you the correct value and part position tomorrow when i'm back at work
these bars could be a earth problem as well/instead of or a signal frequency issue-thats why a pic would be better

[borg07of09]

im running virtua tennis (naomi) inside the machine.  i tried to swap to other games like atomiswave games in hi res but it has the same problem as well.

i tried to manual degauss it with a degauss coil... same problem.  tried to move cabinet around the room in different areas of it and in different rooms, same problem.

i see the cap on the neck card.  its a black cylinder shape.  i dont see any other type of cylinders like that on the neck board.

i appreciate in youre finding out what part i need.  also could i do this with the neck board connected?  as u can tell im not to real verse with electronics.  i know how to discharge a monitor but the nanao has multiple wires that says high voltage.  what do i need to do to put in the capactor.

thanks again for all of your help.

[Kevin Mullins]

Aside from the possible capacitor.... does your cabinet have an EMI filter in the bottom of it?  The cord that plugs into the wall should go through this somewhere.

[grantspain]

with further thought to your problem i believe it is a possible interference issue,can you check one thing for me-disconnect the rgb signal input and turn your brightness up a little so you have a white screen and see if the bars are still there
at the moment my thoughts are the following;
electrolitic capacitor fault on the monitor chassis
earth problem
power supply problem
and another possibility is what kevin mentioned,to do with mains interference

[grantspain]

one further thing,you are aware dip switch no1 on the naomi motherboard switches the frequency,have you tried that?-mind you that would give two pictures if it was the wrong freq

[borg07of09]

ok after fooling with settings of camera i was able to take this picture.




im not sure what you meant by disconnect input rgb signal.  i disconnected rgb connector from chassis while vga cord was connected.  was this what i was suppose to do?

i dont get a white screen but a black screen with what you see there.  there seems to be seem white (other colors... hard to tell on the outer edges of monitor)

is there anything i could try.  thanks again.

btw the dip swith setting is right.  i did try to put it to low res but picture split in 2 or so.  so its on the right setting.
 

[grantspain]

is this an astrocity or naomi cab?you have a small degauss issue at the bottom,when i said dis the signal you need to turn up the brightness to get the white screen-this is to prove whether this is a power or signal problem-is the chassis earthed?

[borg07of09]

this is a naomi universal.  i turn up the brightness so instead of the screen being black its now a little whiter.  its not really white white though if thats what you mean.   i see flickering on the screen.  its hard to say if its bars scrolling from the bottom up.  i took a picture but it looks like the screen is pefect.



as for the chassis... here is a picture.  as for it being ground im not sure if it is.  how could u tell if it is or not?



here is the motherboard and etc if this helps any.



anything else u could suggest i do would be appreciated.  thanks again.

[grantspain]

if the screen just went like this one day then its definately a cap on the monitor chassis-if so your best bet is get a complete electrolitic cap kit and replace the lot,bit of a long job but worth it and yes you will need to remove the monitor chassis and discharge the ht-all our naomi have sanwa chassis,only our older sega have nanao(strange)
the only other thing i can imagine is some sort of problem on the naomi motherboard(on the signal out),but its unlikely-one thing worth trying is to disconnect every thing from the naomi except power,usb and r,g,b-see if that helps(reconnect your monitor first)

[borg07of09]

i looked on the chassis and it says nanao on it.  does that mean its a nanao chassis?  where could i purchase a cap kit for this?

i did disconnect everything except the power, usb and rgb and the same thing happened.  thanks again for your help

with what keven said.... what is an emi filter?  do you see that in the picture i provided earlier?

as for the chassis, i see a green wire connected near the vga connection so i assume the chassis is grounded.

[grantspain]

if its says nanao then it is nanao-must be an early cab
you have an emi filter-i have seen it in your pics(they don't go wrong like that)
the green is the ground for the monitor
you can purchase cap kits from many suppliers but depends on where you live,otherwise you download a schematic and note the value's of all the electrolitics and purchase them at a local electronics supplier
i guess you have already tried a different mains socket