Re: Re[2]: Re[2]: Ms. Pac-Man Monitor (WG?) bends UPDATE

peter jones wrote:
> -----Original Message-----
> From: Tim Soderstrom <tim@moocowproductions.org>
> To: rasterlist@vectorlist.org
> Date: Thu, 14 Sep 2006 11:09:48 -0500
> Subject: Re: RASTER: Re[2]: RASTER: Ms. Pac-Man Monitor (WG?) bends UPDATE
>
>> Alright so all I had lying around was 1500 grit metal polishing
>> sandpaper. That seemed to pickup some of the grift, however. The
>> fuses are less than a year old and look to be in great shape as well.
>> The only problem is, that didn't really fix anything :/ The hum is
>> still on the speaker and the bar on the right hand side of the
>> monitor is still there.
>
> the hum on the speaker is poor capacitors in the amp/psu circuits not smoothing the 50/60hz mains hum.
>
> probably the cause of the bar too.

Let's back WAY up folks:

"the bar on the right hand side of the monitor is still there"---This is
NOT a hum bar, this is his original horizontal sync tear. This will
always be there if composite sync is used instead of separate sync. It
can be minimized by careful adjustment of horizontal hold/horizontal
frequency/horizontal phase (or whatever creative term they use on this
particular monitor).

A hum bar will usually drift across the screen. Remember the simple hum
bar rule:
        ONE hum bar=bad diode, fuse, or connector resistance
        TWO hum bars=bad capacitor

Remember, this is MS Pac Man, the power supply circuits are on the game
board, the capacitors are on the game board. If the hum isn't loud
enough to be a bother LEAVE IT ALONE. A lot of these games hummed a
little mostly due to grounding and unshielded wiring.
---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Fri Sep 15 12:14:58 2006