Re: GO7-CBO (13") flyback?

David Shoemaker wrote:
>
> Well this is interesting.
>
>
>
> I did verify all the caps were the right way around. And the picture
> was really good other than the curl.
>
>
>
> I had tested the monitor on the bench using a robotron boardset. Had
> pretty bad curl.
>
>
>
> I put it back into the Rally X mini that it came from and the picture
> was perfect (well it was too small width wise but other than that it
> was perfect). I replaced the .53 C515 with a .25 and that fixed the
> width issue.
>
>
>
> No idea why robotron would have that curl where rally x doesn't but I
> am going accept and move on with my life J
>
>
>
> Thanks,
>
> David
>

I had a chat back in the late 90s with a Wells Gardner tech about the
variety of boards used in their 4600 series monitors, he told me that
they pretty much had to tune (read modify) the Hor/Vert boards to each
game ordered as there was no standard for the Vertical or Horizontal
frequencies. WG did not keep the data either so he couldn't send me
anything to help sort out bad locking to sync. This led to all sorts of
problems where a monitor would work in one game, but not in another
without mucking around for a while...

The big advantage the Electrohomes had over WG was they would lock onto
a broader range of frequencies with little or no modifications
required...usually.

So, there you have it - the game board sync is the problem, not the monitor!

John :-#)#
>
> *From:* owner-rasterlist@vectorlist.org
> [mailto:owner-rasterlist@vectorlist.org] *On Behalf Of *John Robertson
> *Sent:* Tuesday, April 03, 2012 9:44 PM
> *To:* rasterlist@vectorlist.org
> *Subject:* Re: RASTER: GO7-CBO (13") flyback?
>
>
>
> David Shoemaker wrote:
>
> So it was working (with original 1981 caps), I was in a hurry to use
> it last weekend so figured I would recap it this week....
>
>
> Went dark having blown fuse 901
>
>
>
> I recapped it, replaced fuse 901 and replaced the HOT though it tested
> good.
>
>
>
> Turned it on and got HV for a split second then 901 blew.
>
>
>
> HOT now shorted. Borrowed a ringer and it showed the flyback toast.
>
>
>
> Replaced Flyback, HOT and fuse 901.
>
>
>
> Comes up with a good picture except for the curl.
>
>
> Check that you have the caps in correctly. It is unlikely that the
> flyback would create the curl. The other thing to check is what is the
> HV you are getting from this unit? I think the 13"chassis ran at 100V
> instead of the 123V of the GO-8s, but - well, I'm at home and the
> files are at the shop - I could be wrong on the voltages.
>
> There was a mod suggested for GO-7s to improve the sync, did your cap
> kit include the following info?
>
> "There is an optional C303 upgrade. Some claim it helps with screen
> "curling" problems. Here are the steps for that modification.
>
> 1. Remove C501 and discard.
> 2. Remove C303 and install it where C501 was installed.
> 3. Remove the solder from the hole that is in the middle of the two
> holes where C303 originally resided, and fill the C303 hole farthest
> from the board's edge with solder.
> 4. Insert new cap (10 mfd 50v) in the cleaned holes, with the
> positive lead closest to the edge of the board (to the collector of X305).
> 5. After installation, you may need to adjust the Horizontal Hold.
> Hole you don't have to, as the HHold coil is usual pretty fragile from
> heat stress. Leave it alone if at all possible. "
>
> John :-#)#
>
>
>
>
>
> *From:* owner-rasterlist@vectorlist.org
> <mailto:owner-rasterlist@vectorlist.org>
> [mailto:owner-rasterlist@vectorlist.org] *On Behalf Of *John Robertson
> *Sent:* Tuesday, April 03, 2012 9:18 PM
> *To:* rasterlist@vectorlist.org <mailto:rasterlist@vectorlist.org>
> *Subject:* Re: RASTER: GO7-CBO (13") flyback?
>
>
>
> David Shoemaker wrote:
>
> I have a monitor that ate the flyback. I couldn't find anyone that
> had the 13" specific flyback so I put a 19" flyback in. It all works
> fine except part of the screen is pretty badly curled (about the top
> 1/2" or so). No adjustment fixes it.
>
>
>
> Any suggestions on getting a solid picture on these or a direct
> replacement flyback source?
>
>
>
> Thanks,
>
> David
>
> Did you recap the monitor at the same time?
>
> Bad caps eat flybacks...
>
> John :-#)#
>
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> www.flippers.com <http://www.flippers.com>
> "Old pinballers never die, they just flip out"
>
>
>
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> www.flippers.com <http://www.flippers.com>
> "Old pinballers never die, they just flip out"

-- 
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
                 www.flippers.com 
"Old pinballers never die, they just flip out"
---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com