Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

chaozz

macrumors Chihuahua
Original poster
Mar 9, 2025
1
0
I am trying to figure out why my iMac G3 won't boot. The component I am currently suspicious of is the transformer on the pictures.

From the 4 wires in to the 9 wires out it seems to have two primary windings, and then 4 secondary windings + a center tab. Please correct me if I'm wrong, I'm a noob in electronics.

I can't find any details on this transformer, of the schematics of the board. I measure 130v AC going in, and 1 to maximum 3 volts AC going out. My guesstimate is that this should be a 130v AC to 12v AC stepdown transformer and the component is bad.

So, am I correct in my assumption and are there any drop-in replacements available. If not how do I go about and fix this?

Also, schematics would be awesome but I'm drawing blanks.
 

Attachments

  • 20250308_200635.png
    20250308_200635.png
    1.6 MB · Views: 31
  • 20250308_201918.png
    20250308_201918.png
    2.3 MB · Views: 19
  • 20250308_201855.png
    20250308_201855.png
    2.3 MB · Views: 18
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.