SE fan troubles and an unknown brown substance

[Apostrophe]

Hi,

I have my second SE open to remove and clean the fan. Aargh! I was able to loosen and remove all screws holding it onto the board (the analog board, I presume?), but there is a set of two very stubborn wires that are glued in several places to the board, with the fan at the other end! What can I do to remove the fan?

But the main reason I posted this was to ask: is it normal for there to be a brown, crusty, dried-glue sort of substance covering one of the components? It's not a capacitor, but I'm not sure what to call it. And it's covered in this crusty brown stuff; is that normal?

I'll upload pics as soon as I find my USB camera cable...

-Apostrophe

 

[Apostrophe]

Ok, here are pics:







What could this be? Do I need to replace that component?

-Apostrophe

 

[OtakuMegane]

That would be the flyback transformer. It handles the high voltages needed for the screen. The brown stuff looks like a glue or sealant that's broken down due to age/heat. Unless someone else has suggestions, I'd say just leave it be if you aren't having trouble with the screen.

 

[JDW]

The "crusty" substance you refer to is in fact EPOXY. It is an important, albeit unsightly, seal on the flyback transformer. Per Larry Pina atop page 96 of his excellent Macintosh Repair and Upgrade Secrets book, broken epoxy seals result in ringing noises. This could result from a broken seal at the top of the flyback (the "top" is the location of the seal you have pointed out to us) or from a broken epoxy seal at the bottom of the flyback (which cannot be viewed until you desolder and remove the flyback). Epoxy can be repaired in most cases by applying new epoxy, but as Pina states, it's often best to just replace the flyback. In any event, you need not worry about replacing the flyback unless you hear unusual noises, or perhaps if you see wiggling on your screen or smell ozone.

I have take some photos in the past which show how my Mac128/512 and SE/30 flybacks look, with uncracked epoxy in good condition:

• Pre-Mac SE Analog Board: look to the left of

this photo.
Pre-Mac SE Analog Board: look to the upper left of this photo.
SE/30 Analog Board: look to the upper right of this photo.
SE/30 Analog Board: look to the upper right of this photo.

 

[Apostrophe]

Ohhhh, okay. Thanks.

The screen's fine, as far as I can tell, but at the moment all I get is the 'sad mac' surrounded by a black screen when I turn it on. But once I replace the hard drive, that problem should be fixed as well.

Which is good; now I only have to get a hard drive without having to worry about getting a flyback as well!

Thanks,

-Apostrophe

 

[OtakuMegane]

The "crusty" substance you refer to is in fact EPOXY. It is an important, albeit unsightly, seal on the flyback transformer.

Ah, that's what I was looking for. It's been quite a while since I worked inside something with a CRT.