Re: Vectorbeam monitor issues

The X amplifier is working okay. The Y amplifier is not working on the negative supply side (top half is blank) and it
also appears that the Y power transistor on the positive supply side is not working, that's why it's compressed. I
would expect from the pictures also that the LF13331 quad switch IC is shot. It is latching both endpoints of Y but
only one endpoint of X.

Bill Boucher
http://www.biltronix.com

>
>
> I installed a 7406 and the intensity issue is fixed. I guess I mis-read
> the part number... or I'm going crazy. I left the diodes in place.
>
> This is where it's at now: the image is compressed into a band about three
> inches tall. The vectors do not align.
>
> Tail Gunner title
> screen<https://lh6.googleusercontent.com/-QTu_tZiCu4Q/UVHJvPk0trI/AAAAAAAAKCE/H_rt2FjSdPU/s895/IMG_0008.JPG>
> Push Start Credits
> 1<https://lh3.googleusercontent.com/-tFQ_GEJZJ6Q/UVHJv5uSUaI/AAAAAAAAKCM/wTEp0_cz9HI/s895/IMG_0009.JPG>
>
> Any insights are appreciated.
>
> Carlos
>
>
> On Tue, Mar 26, 2013 at 10:40 AM, Carlos Rubio <csrubio@gmail.com> wrote:
>
> > Correction to my original post:
> these<https://lh3.googleusercontent.com/-aQ9D82rvVr4/UVGOweZsPXI/AAAAAAAAKBk/E1w6AkFky-g/s895/IMG_0007.JPG>diodes are
> between pins 1 and 14 and 3 and 14. >
> > Carlos
> >
> >
> > On Tue, Mar 26, 2013 at 10:28 AM, Carlos Rubio <csrubio@gmail.com> wrote:
> >
> >> One reason I hesitated on changing the 7409 to a 7406 is it looks like a
> >> factory mod and I wasn't sure if other parts of the circuit had also been
> >> modified to accommodate the 7409. The reason I think it's a factory mod is
> >> because Bill Boucher's NIB Space War has a monitor identical to mine, and
> >> his also has the mod as can be seen
> here<http://www.biltronix.com/images/space_war/2008_11_22/vsw_2008_11_22_05.jpg>. >> I'm hoping someone here can help
> me understand this. >>
> >> I will swap it with a 7406, but should I leave the diodes in place?
> >>
> >> I forgot to mention in my original message that I verified the .5 amp
> >> fuse in the power supply is good.
> >>
> >> I will check C10, thanks for the suggestion.
> >>
> >> Carlos
> >>
> >>
> >> On Tue, Mar 26, 2013 at 10:06 AM, Rodger Boots <rlboots2@gmail.com>wrote:
> >>
> >>> 7409 is wrong part, change it to 7406.
> >>>
> >>>
> >>>
> >>> On Tue, Mar 26, 2013 at 7:14 AM, Carlos Rubio <csrubio@gmail.com> wrote:
> >>>
> >>>> Hello, I'm working on a Vectorbeam monitor on which I've replaced about
> >>>> 90% of the components. This monitor is the "discrete" version with the HV
> >>>> components on the monitor PCB. It also uses the older part numbers.
> >>>>
> >>>> Currently the screen is blank, but I'm not sure if it's a problem with
> >>>> the intensity circuit or a legitimate spot killing. Jumpering Q2 (labled
> >>>> Q24 on my board) causes the picture to appear and reveals that the top half
> >>>> of the image is missing. All transistors have been replaced.
> >>>>
> >>>> I should also mention that this monitor has a 7409 at IC7 (labeled U6
> >>>> on my board) instead of the 7406 referenced in every document and schematic
> >>>> that I've seen. There are diodes between pins 1 and 8 and 3 and 8 as seen
> >>>> here<https://lh3.googleusercontent.com/-aQ9D82rvVr4/UVGOweZsPXI/AAAAAAAAKBk/E1w6AkFky-g/s895/IMG_0007.JPG>.
> >>>> I've replaced the 7409 and the diodes with new ones, exactly as they were.
> >>>> The symptoms were the same before and after.
> >>>>
> >>>> I'd appreciate any insights in understanding if one problem is related
> >>>> to the other, and how to narrow down the fault(s). Thanks,
> >>>>
> >>>> Carlos
> >>>>
> >>>
> >>>
> >>
> >
>
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Received on Tue Mar 26 13:03:30 2013