Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: arfink on April 17, 2020, 06:57:09 pm

Title: Abnormally loud flyback- causes, fixes?
Post by: arfink on April 17, 2020, 06:57:09 pm
I've got a monitor with an abnormally loud flyback. Is this an issue with a common cause? Will a recap potentially fix this, or do I need to replace the flyback? Also, should I be concerned about this being misadjusted and making x-rays in this case? Thanks!
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: MKFan4Life on May 04, 2020, 03:24:30 pm
Loose ferrite core? High-pitched squeeling, right? Try reading this article from Bob Roberts:

http://www.thegleek.com/bobroberts/whiny.html

 ;D
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: arfink on May 05, 2020, 12:58:41 am
Thanks, that seems like an interesting solution, just dampening it. My flyback is an older 80s two piece affair, with the C shaped part in one module, and the screen and focus adjustments potted into another module, with high voltage leads between then. So I'll have to determine which part is making the noise and try to dampen it individually.
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: MKFan4Life on May 08, 2020, 12:00:06 am
Hope it works for you. If so, let us all know!

I had a singing one in a K7400. Worked well for a few years, then acted like it didn't want to come on a few times. Next time, it wouldn't come on at all. I had bought another working K7400 and just swapped them out to get my MAME cabinet up and running quickly.

I assumed it was that flyback, as I had never changed it out. Only put new neck transistors in it when I bought it used. But I noticed a bulging cap as I was putting it away. Think I'll do a recap to see if it fixes it, then likely put in a new flyback since I have one for it now.

 :P
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: arfink on May 08, 2020, 08:42:46 am
I would totally do a flyback swap on this one, but like I said, it's a super-weirdo flyback that I've been totally unable to find a replacement part for. I'll have to take some pics. Hopefully today will be the day to work on it some more.
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: arfink on May 08, 2020, 10:47:12 am
Updated to say that pressing with my finger on the certain parts of the ferrite core while it's turned on (I know, reckless!) definitely silences the squeal, so this is on the right track.
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: MKFan4Life on May 08, 2020, 03:45:20 pm
Yeah, I don't know if I'd replace it if it's functioning ok. I'd try a wedge. Maybe wooden, or maybe even a rubber wedge used for monitor yokes (if you cut it down into smaller pieces). You might get it to quieten down.
Title: Re: Abnormally loud flyback- causes, fixes?
Post by: arfink on May 08, 2020, 11:51:18 pm
Yeah, I don't know if I'd replace it if it's functioning ok. I'd try a wedge. Maybe wooden, or maybe even a rubber wedge used for monitor yokes (if you cut it down into smaller pieces). You might get it to quieten down.

Yup, I was thinking that or I have some pieces of neoprene sheet I could cut up and use for jamming into crevices as necessary. Of course, all of this assumes I can figure out the issue I'm having with my RGB signals going into this thing. RGB modding is not doing well. This was a high-end consumer monitor, not an arcade monitor, and so it was not designed for 15khz analog RGB, but rather accepted both NTSC composite and TTL RGB. I've been getting closer to having it work, but it's having some issues still, and I'm pretty stumped after today.