I was gonna post " Davey will find better discussion, in a iMac repair email group.". Sure enough, Davey is in the vcfed.org "early PowerPC Macs" forum, photo and all, with details. Davey focused on the flyback. But it might be useful, to focus on the horiz output transistor. Be sure it matches *brand* as well as part-number. Exact replacement horizontal transistors on CRTs is often necessary - it's an analog circuit that is sensitive that way. But it's odd to see action as described. This may be a more classic "TV" problem, like that transistor. I'll post some details in the PowerPC list. Jeff Brace:
You will need to provide a link to the picture because attachments don't .. If you are local, then I suggest that you bring it to our next repair workshop
On Sat, Nov 18, 2023 at 3:33 PM Daveyk021 wrote:
Are there any iMac G3 experts in the group?
I replaced the [iMac G3] flyback and horz output to get this iMac to come on. The unblanking has vertical strips in it, missing video. This one had worked almost perfectly until the first time I turned it off (it was having display size jittering, and some flashing, so I assume the flyback was failing). If I changed the OS resolution down to 800x600, the blank vertical lines are still there... So it kind of looks like a really weird unblanking issue. I cannot find schematics for this thing anywhere.
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