Mac Plus HIGH-PITCHED sound

[mloret]

Hello! I recently purchased a Mac Plus. I've gotten it running and with a working floppy. Occasionally it makes a VERY high-pitched noise. I suspect it's coming from the CRT as it's that kind of noise, but I am not sure. The machine hasn't been recapped. Any idea what this could be?

 

[Johnnya101]

Bad flyback? Would make sense in a Plus as they tend to overheat.

Bad news is new ones are $100+. Good news is suitable used replacements are easy to find.

 

[mloret]

Yes it gets really hot in the vents above the flyback. Arg. You recommend ebay?

 

[Johnnya101]

It all depends on what you want to do. Personally, if I wanted to use it instead of just having a Plus sitting on a shelf or whatever, I would spend the $100+ on a new flyback just to have a new one. You will need to remove the back, discharge the CRT, remove the paper backing off the analog board, unsolder the old flyback and solder the new one on. May as well resolder all the solder joints on there as well, they tend to go bad.

Here's a used one off ebay: https://www.ebay.com/itm/185305390334?hash=item2b250fdcfe:g:w9AAAOSwvEhiEont (IMO Way overpriced for one in that condition).

Here's a new one: https://www.ebay.com/itm/121655780759 (Pretty large volume discount, they may accept an offer around the $130 range).

The heat above the vents is normal as there is no active cooling in a Plus. I'd wait before jumping to buy a new flyback for someone else to post their ideas just in case there is something else I am missing.

You could also ask around on here for a used one, someone may have one laying around.

 

[mloret]

Ok. Thanks for the advice. I'm a little nervous about desoldering the flyback. I'm just working with a braid and I fear that i would wind up wrecking a pad or something. I might be better off just getting a board.

 

[Johnnya101]

Actually, in your case, I would send the whole board out to someone to recap it, such as Amiga of Rochester, and have them install a new flyback for you. That ways all the caps are replaced and you get a new flyback installed. That's IF it is the flyback going, just wait for a confirmation from another member before doing anything.