Problems with the green channel on my Blitz 99

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hi,
The green channel on my Blitz 99 cabinet works sometimes and sometimes
does not. It is very random. Sometime it will play fine for a few hours
and sometimes it will only last a few minutes.
Can anyone give me some suggestions on what the problem maybe or where
to start looking for troubleshooting?
It has a Wells Gradner Medium Res. monitor.

Any help is greatly appreciated.

 

[RJ]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hi
Has the monitor been capped and the external connection points/flyback
been reflowed?
Allso check the neck board transistors, they may need to be reflowed..

Check the RGB Snyc connector going into the WG and also check /clean
receed your Jamma connector on your game board. I use a Scotch bright
pad to clean the edge connector or a NO. 2 pencil eraser works.

RJ

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hi RJ,
I know for sure that the monitor was repaired before I bought it,
because it had a repair ticket still on it. Unfortunately, the ticket
did not say what was done to it and since I bought the machine at an
auction I have no way of finding out what was originally wrong.

I did check the RGB sync wires and they are all good with no shorts.
I also have checked the edge connector on the Jamma harness and it is
nice and clean and seated on the board properly.

Is it possible this is a cap problem? I thought if it were the
capacitors then I would simply not have any green channel at all.

I will reflow the parts you mentioned. Hopefully it will work.
Thanks for your help!

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hi Steve,
I will try your advice. I will get out my old solder gun and see what
I can come up with.
Thank you for your time!

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Because it's intermitant it could be almost any component. The most likely
cause is a cold solder joint/broken wire somewhere...

your best bet would be reflow the chassis (concentrating on the neck board
and the input section (a goodly portion is taken overy by sync which appears
to be working in your case so you don't have to worry about that).

The other thing to check is the cables... I know you checked them for
shorts... but in this case it's actually OPENS that you need to worry
about... this may also be positional so you'll have to jiggle things around
while you're checking to see if it fails (atleast it's only the green so you
can concentrate on that wire alone)... you also need to check the green from
the chasis to the neck board.

You might also want to check the green intensity/cut-off pots on the neck
board... if the sweeper is going bad it could intermittently be going high
or low.

steve


"I Tune LOW" <thephv@hotmail.com> wrote in message
news:1119369388.539509.305090@g44g2000cwa.googlegroups.com...
> Hi RJ,
> I know for sure that the monitor was repaired before I bought it,
> because it had a repair ticket still on it. Unfortunately, the ticket
> did not say what was done to it and since I bought the machine at an
> auction I have no way of finding out what was originally wrong.
>
> I did check the RGB sync wires and they are all good with no shorts.
> I also have checked the edge connector on the Jamma harness and it is
> nice and clean and seated on the board properly.
>
> Is it possible this is a cap problem? I thought if it were the
> capacitors then I would simply not have any green channel at all.
>
> I will reflow the parts you mentioned. Hopefully it will work.
> Thanks for your help!
>

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Please don't use a gun, unless you mean an iron. I'd second the neck
board solution. Had one with red out that the trace had lifted off the
board and had broken in two. While you're there, if any other traces
are coming off the board, put a jumper wire in if nescessary to
directly connect the component legs. Those neck boards get crispy.

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

sorry, yes I meant iron.... lol

I have isolated the problem to the monitor by swapping out monitors
with an identical one that works fine. The problem is definately the
monitor.\

I reflowed the neck and chasis boards and still have the same problem.

The guy at Zanen Electronics (very helpful) thinks it could be a video
transistor.
I noticed the video transistor area on this board look like they have
gotten very hot at one point. So I ordered some new ones and will try
that.

What would cause the video transistors to overheat?
This is maybe something I need to answer so I dont fry the new ones if
they are the problem to begin with. Anyone?

btw, my monitor is a WG U5000.

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

It seems like the case with transistors in monitors, there are a lot
more incidences of "leaky" ones than other applications. I'd agree
with you re: failures are usually total and easy to detect in other
applications though.

Mike Doyle

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

It could certainly be the video transistor... however I since it is
intermittently working perfectly I would suspect that it would *not*
actually be the case. (someone correct me if they think I'm wrong, but in
generall when I've seen transistors go bad they generally go totally bad...
intermittent (except for bad supply voltages) seems to be very rare).

"I Tune LOW" <thephv@hotmail.com> wrote in message
news:1119474979.158126.145590@z14g2000cwz.googlegroups.com...
> sorry, yes I meant iron.... lol
>
> I have isolated the problem to the monitor by swapping out monitors
> with an identical one that works fine. The problem is definately the
> monitor.\
>
> I reflowed the neck and chasis boards and still have the same problem.
>
> The guy at Zanen Electronics (very helpful) thinks it could be a video
> transistor.
> I noticed the video transistor area on this board look like they have
> gotten very hot at one point. So I ordered some new ones and will try
> that.
>
> What would cause the video transistors to overheat?
> This is maybe something I need to answer so I dont fry the new ones if
> they are the problem to begin with. Anyone?
>
> btw, my monitor is a WG U5000.
>

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Your next bet would be to acually remove the pots and check them... or, if
you're not sure you could just swap the green and red pots and see if the
problem moves...

"I Tune LOW" <thephv@hotmail.com> wrote in message
news:1119474979.158126.145590@z14g2000cwz.googlegroups.com...
> sorry, yes I meant iron.... lol
>
> I have isolated the problem to the monitor by swapping out monitors
> with an identical one that works fine. The problem is definately the
> monitor.\
>
> I reflowed the neck and chasis boards and still have the same problem.
>
> The guy at Zanen Electronics (very helpful) thinks it could be a video
> transistor.
> I noticed the video transistor area on this board look like they have
> gotten very hot at one point. So I ordered some new ones and will try
> that.
>
> What would cause the video transistors to overheat?
> This is maybe something I need to answer so I dont fry the new ones if
> they are the problem to begin with. Anyone?
>
> btw, my monitor is a WG U5000.
>