Fixing a IIgs monitor?

#1 Wed, 30 May 2012 - 23:02 68kMLA

I have an Apple IIgs in OK condition. The monitor is giving me issues. First, it makes a horrible high pitched sound when turned on (only slightly subdued when there's a picture on the screen, but still rather intolerable.) Second, the picture is near the bottom of the screen because if I adjust the vertical location, the picture becomes completely distorted and starts scrolling up and down.

Is this something I can repair? Anyone here used to fix CRTs?

Thanks

#2 Thu, 31 May 2012 - 03:13 68kMLA

Have you checked the capacitors?

#3 Thu, 31 May 2012 - 17:04 68kMLA

Try the TV repair FAQ. It's out there on the interwebs someplace.

#4 Sun, 3 Jun 2012 - 15:14 68kMLA

kinda hard to tell by the description. Might need to do a short video or picture showing the symptoms.

The squeal is caused by a loose core in the flyback IF it sound like a 15khz squeal? The other issue sounds like a fault in the vertical circuit.

But at the same time, it could be all in the power supply and squeal is coming from there as well, and rendering a low B+ voltage. Does the picture appear to be slightly smaller than usual? not quite as much brightness, or brightness causes the raster to bloom? This would be indicative of low B+