Recently acquired Supermac card for my IIci

[rafthe030]

So i bought that Supermac thunder /24 (rom v3.00) to get better screen resolutions and to switch between them without having to play on the adapter switches.

Pulled the 8•24 gc from my mac IIci and put the supermac instead. Works fine and has good image quality, except for the horizontal waves that show up occasionnally and half of the screen that sometimes move for a tick.

I tried two other lcd displays, other apple multisync cables, reslotted it once and plugged it directly to the display(I use a display switcher). The waves are still showing up and the screen still moves sometimes.

Then I started wondering 'Could the problem be due to any component on the supermac's board?'

So I ask here to see if anyone knows any related problem that can be fixed for the Supermac, or what component could it be. I will try cleaning contacts first. I will maybe try recapping after if this can be my solution. Any answer will be appreciated.

 

[Unknown_K]

Have you tried a CRT?

 

[rafthe030]

I don't have one for now. I should try, though!

I changed my mind about recapping, since they all are surface-mount ceramic capacitors.

At least I retried my sony 17" and horizontal bars are less visible and less frequent. The other problem seems to be gone.

 

[olePigeon]

If it makes you feel any better, I also have a SuperMac video card that has problems syncing with LCDs.  I have to tell the LCD to auto-adjust nearly every time I turn on the computer.  My Radius video card handled LCDs much better.

 

[Unknown_K]

Early cards have weird sync frequencies or used fixed frequency monitors so LCD monitors hate them.

Even much newer cards can have issues with LCD monitors. I have a PCI CAD card that does 1920 x 1080 at 60hz but my 1080p 24" DELL doesn't sync to it at that (native) resolution so I have to use something smaller.

 

[rafthe030]

Makes sense to me. At least I can get a nice 1024x768 in 32-bit colors and switch between sizes. What I was hoping for.