I'm looking to fix a computer monitor with VERY poor convergence.

[jmetal88]

I finally ordered a kit off eBay today. I guess we'll see toward the end of next week how making these adjustments affects the convergence.

[jmetal88]

Well, now I have a bigger incentive to get this thing adjusted properly, as my favorite CRT computer monitor, my Samsung Syncmaster 17GL, has just bitten the dust. The image on it went REALLY narrow and unstable today. I unhooked it, took it apart, re-soldered a couple of bad-looking joints on the flyback, and put it back together, but the situation only improved by the instability going away. The picture is much too narrow to be usable on it now. Unfortunately, though I've been able to find the schematics for the Samsung, they are VERY complex, and I'm having a hard time even finding which part of the circuit I think I should be looking at, so I think I'm just going to consider it a loss and focus on making this CompuAdd monitor looking as good as I can instead.

[jmetal88]

Aw man, I got the alignment kit in, picked the closest fit, and tried to give that inductor at the back of the yoke a turn... It's cemented in place, so it's not going anywhere. In fact, the alignment tool (I had my pick of slightly too small or slightly too big) just started slipping around inside the inductor core after I applied a certain amount of force. I guess my last shot before trying to break the yoke free and move it actually would be re-capping this thing now.

[jmetal88]

Actually, the more I use this, and the more I look at all the little distortions on the screen, the more I'm suspecting that the yoke has deformed, possibly due to heat or something. It's certainly still glued in place where the three wedges are, but that doesn't mean it hasn't warped in the spaces between them. I might still re-cap it, just to try to give it some extra longevity, but I don't think I can expect an electrical fix for the convergence issues.

[jmetal88]

Hmm, I've found someone apparently selling a new CRT that matches the one in this monitor. I've e-mailed them to ask if the yoke is attached (they show a picture of a CRT with yoke attached, but have a note saying it may not represent the actual item). If it is, it may potentially solve two problems for me, one being the deformed yoke (if that actually is what's causing my convergence issues) and the other being the small abrasion on the face of the CRT. It's a pity it's as expensive as it is, but considering I've been looking up new-old-stock CRT monitors and most of them sell for about twice as much as this tube, I guess it's not too bad a deal.

[old_tv_nut]

"may not represent the actual item"

Personally, I would not buy unless the seller provides a picture of the actual item, as well as verifying it's the right one.

[MRX37]

Another option if all else fails are believe it or not, pieces of refrigerator magnets taped to the corners of the CRT back. It takes some fiddling with size pieces and positioning but it can help.

[jmetal88]

Originally Posted by MRX37

Another option if all else fails are believe it or not, pieces of refrigerator magnets taped to the corners of the CRT back. It takes some fiddling with size pieces and positioning but it can help.

Yeah, I remember when I took apart the 32" Trinitron TV I had a few years ago I saw that it had magnets glued to the back of the CRT for that purpose. Usually that's only necessary on larger CRTs, though, which is what makes me think something more is wrong with this monitor.

I have a short strip of refrigerator magnet material that I tried positioning on the back of this CRT, but I didn't see any positive effects from it, at least not the way I was trying to use it.

[Chip Chester]

Have you made the rounds of your local tech buddies, recycling businesses, etc. to see if someone has a decent complete CRT monitor to just give away? It's likely only the better ones were kept around over the years...

Chip

[jmetal88]

No, but I want this one in particular because it's the same brand as the computer I'm using it with.

[wkand]

Maybe someone mentioned it, but reading the entire thread, I did not see mention of any setup key or menus. I have never see a CRT monitor that relied entirely on internal adjustments for convergence, brightness, contrast, etc.

[jmetal88]

Originally Posted by wkand

Maybe someone mentioned it, but reading the entire thread, I did not see mention of any setup key or menus. I have never see a CRT monitor that relied entirely on internal adjustments for convergence, brightness, contrast, etc.

This is a 1992 monitor, it's too old for that. All the screen size, position, pincushion, etc are all done with individual potentiometers.

[kf4rca]

I'd try to get your Syncmaster going if at all possible. The Syncmaster is like the Sony Multiscan which is like the NEC Multisync.
Unlike most monitors that are fixed frequency types the Syncmaster is a variable frequency type. It locks to whatever is given it.
If you ever get a Sun Microsystems computer, you will need the Syncmaster.

[andy]

...

[jmetal88]

Originally Posted by kf4rca

I'd try to get your Syncmaster going if at all possible. The Syncmaster is like the Sony Multiscan which is like the NEC Multisync.
Unlike most monitors that are fixed frequency types the Syncmaster is a variable frequency type. It locks to whatever is given it.
If you ever get a Sun Microsystems computer, you will need the Syncmaster.

I already gave away the Syncmaster. I was NOT AT ALL interested in trying to troubleshoot the horizontal circuitry on that considering how complex it was.