I have an experience with bad flyback transformer in Mac Plus. Flyback 
transformers have different ways to fail. In my case, there wasn’t high voltage 
on the CRT but I could hear the start up chime and activity in the FDD (loading 
OS). I took away the fly back transformer from a Mac 512K analog board (same 
part number). This model of flyback is discontinued.

Yes, it is easy to desolder and the drop a used one. As others advised you, do 
not discard the capacitors. Also take a look of the physical appearance of all 
of the components, like burned resistors and/or semiconductors, especially 
transistors. About discharge precautions, unlike newer Macs, Mac Plus’s flyback 
transformer doesn’t have the internal resistor to discharge the CRT (long time) 
when you turn the power off, so always discharge the CRT even when you leave 
the machine unplugged overnight.

 

For these old machines is a good idea to have a donor to swap components/parts. 
I like to replace the capacitor for the new ones, but I did this only in know 
working computers.


Regards,

 

Rodolfo

 

(sorry for bugs in my English)
 
> From: [email protected]
> Subject: Mac Plus flyback transformer?
> Date: Mon, 24 May 2010 15:10:36 -0700
> To: [email protected]
> 
> I have a Mac Plus that I'm pretty sure has a bad flyback transformer. When 
> you flip the switch, it makes a sort of rhythmic clicking, and nothing else 
> happens. I opened it up, and the flyback has white and brown residue on it in 
> certain areas. 
> Can you get new transformers? If so, where could I get one? Or is it better 
> to just get a new analog board? How hard is it to replace the transformer? It 
> looks easy enough to de-dsolder and then drop in a new one. Are there any 
> precautions to take to make sure it's fully discharged? 
> Thanks,
> 
> 
> -Elliott Price
                                          
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