k4900 why does my screen look like this?

tron guy

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I pulled the chassis off of the yie ar kung fu that I had that needed a cap kit, and put on a chassis that I just tested in a qbert a few weeks back. It worked perfectly.

right now this is what my screen looks like.

Can anyone tell me how to adjust it back to centered?
 

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Ha!!! My Yie Ar did the SAME Thing. I ended up being a ground issue (incorrectly grounded) monitor. Check it.

I am trying to picture where I should be checking.

I suppose it could be the long black wire from the neck board that I connected to the wire that surrounds the tube? Is that the culprit?
 
I don't recall exactly, but I think I had a bad ground going to the chassis (The RGB WB connector), then I had to ground the monitor frame too. That issue kicked my ass for a week!
 
I dont think the sync pins are used at all on this monitor.
are you referring to the pins right above the color pins on the chassis? if so, none of my 4900's use those pins.
 
The pins on the 6-pin section are positive sync and the ones on the 3-pin section are negative sync. if you horizontal hold adjustment doesn't help, switch the sync from one side to the other.

And if its on the 3-pin side right now, and the sync is jumpered between the 2nd and 3rd pin, remove the sync from the 2nd pin. The K4900 doesn't like the negative composite sync to be on the vertical sync pin...
 
the thing that's buggin me about this is:
a few days back the chassis was perfect when testing on a qbert. I move the chassis to another tube (4900 was on the tube a few minutes before) now I get this problem.

Mod are you suggesting I pull the sync wire out of the 6 pin connector that is attatched to the board and put it in the 3 pin molex and try it on the upper set of pins?
 
Mod are you suggesting I pull the sync wire out of the 6 pin connector that is attatched to the board and put it in the 3 pin molex and try it on the upper set of pins?

That is what both Mod, and Dick are saying.

Q*Bert = positive sync
Yie are Kung Fu = negative sync
 
now I would NEVER question insight from you guys. but I am curious why the old chassis is set up the same as this and it worked nicely.
I will just go ahead and do it and report back. gotta wait until later tonite after kids are in bed. what pin should I hook the sync wire to from bottom to top?

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the middle one did he say?
 
I haven't reviewed the scats, so you can't hold my feet to the fire.

yeah no sweat. I will start by making sure the ground on the monitor is good, then move to the sync.
may as well go easy first huh?

thanks guys, I should be able to figure it out now.
 
ok, moving the sync like dick and mod said was perfect, thanks.
problem fixed.

now I still don't have sound.
I even went through a self diagnostic test, and it went through it's 28 sounds like nothing was wrong, but I didnt hear a thing. I tried adjusting what appears to be a sound pot on teh board.

I tested a couple of voltages(right on the edge connector) got +4.84 on the +5 and
-.01 on the +12. does that last part have anything to do with the sound?
 
your +5 is very low.

if it's a switcher, then replace the PSU.

useless info for the day:

if you have no picture, but have sound, it's a monitor issue, not power supply related (because you need +12V for sound, and to produce +12V, your switching power supply therefore must also produce +5V)

if you have picture, but no sound, check the +12V.

that's what I learned from the master jedi tech when I got into this stuff last year. :D
 
your +5 is very low.

if it's a switcher, then replace the PSU.

useless info for the day:

if you have no picture, but have sound, it's a monitor issue, not power supply related (because you need +12V for sound, and to produce +12V, your switching power supply therefore must also produce +5V)

if you have picture, but no sound, check the +12V.

that's what I learned from the master jedi tech when I got into this stuff last year. :D

yeah I already checked that. missing the +12 and it's NOT a switcher.
new thread concerning this topic of no sound with picture of power supply
thanks
 
useless info for the day:

if you have no picture, but have sound, it's a monitor issue, not power supply related (because you need +12V for sound, and to produce +12V, your switching power supply therefore must also produce +5V)

I've had a switcher have +5 and no +12, or vice versa, in the past...
 
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