Color Mac Classic (with LC575 pcb) geometry issue..

[Patchboston]

Hi, 

After recapping the LC575 motherboard and installing a new battery (external), I'm just about finished with this computer. There is only one issue that remains...on the left and right side of the screen, there are mirroring gemetry issues, where the screen kinda "dips" in. 

Here is a pic: 

Are there any known issues I should look into? Or do you suspect this is capacitor related on the analog board? 

Any guidance is appreciated! 

 

[Macdrone]

could be but there are geometry adjustments under the back case.  Take it off and youll see them at the back of the analog board.

 

[techknight]

thats the pincussion circuit responsible for that. 

2 causes. 1 could be a noisy pot and its actually drifted in resistance from the wiper oxidation, Or capacitors.  Id suspect the former rather than latter in this case. 

 

[Scott Baret]

Adjust your screen first. This should correct the issue. I've fixed this problem on a CC before with that adjustment.

Note that you'll have to actually remove the rear cover of the computer. Only the horizontal and vertical shift controls are available on the back of the Mac as-is. You'll also want the appropriate tools. Since TV adjustment tools are so hard to come by these days, I recommend using an insulated tiny flathead screwdriver (I took one from an eyeglass repair kit) for those controls and, for those with the plastic hex, a filed-down plastic kids' watercolor brush (usually a buck or two at Target for a pack of several). File the non-brush end down until it fits the hole. (I actually used one of these on a CC last week).

 

[Patchboston]

Thanks guys, you have given me great info and ideas!

I do have some tv/monitor adjustment tools, so I will take the cover off and give it a peek tomorrow! 

-Dave