Re: Rip Off display of vectors question

Thanks David. I'll let you know what I find.

tm

 
> Hi Tom,
>
> Since you've determined that it IS the high intensity vectors that are missing it should be possible to narrow down the cause. You're going to need a meter to do these tests.
>
> 1) With a meter check the INTENSITY control bit on the
> CPU board with the game operating. This signal can be
> measured on pin #3 of IC J2 (a 74LS32). I would expect
> a signal level between 1.5V and 2.5V with a meter. If
> you've got a scope available it would be easier to see.
> If the signal is <.8V it might be 'stuck' LOW. The beam
> on the CRT is brighter when INTENSITY is a logic HIGH.
> Ohm out the cable between the board and monitor just
> in case there's a break. This is unlikely since it's pin #12
> of the cable.
>
> 2) This test is trickier. You need to measure the 90VDC level
> which it being generated by the Keltron power supply, the
> gold colored box on the right side of the monitor. I always measure
> this at the connector for the Keltron (pin #1 of the 6 pin connector
> is +90V and pin 5 is GROUND) but it can also be measured easily
> on the banded end of diode D4, GROUND can be found
> at a number of points. I strongly suggest getting a copy of the
> schematics for this.
>
> Check out the schematics at Spies if you don't have a set.
> http://www.spies.com/arcade/schematics/index.html
>
> The voltage measured should be roughly 90VDC +/- 10%.
> If it's around 45V you've got a dead Keltron. You might be able
> to find a replacement. Good Luck. I've had good luck
> with an alternate Hi-V supply, one fron a G05. My write
> up is on SPIES. It's called Cinematronic HV Tech.
>
> http://www.spies.com/arcade/info/index.html
>
> 3) If both previous checks are OK and the Hi-V is correct (assuming
> you have access to a Hi-V probe for the meter) then chances
> are is a weak picture tube (19VARP4 or equivalent). These
> tube ARE still available from Richardson Electronics
> try: http://www.rell.com/
> I think they run about $100 and since it's a B/W tube you
> don't have to worry about convergence. Just move the yoke
> and magnet ring assembly to the new tube. Should be fairly
> simple.
>
> Let me know what you find.
>
> Dave
>
> > -----Original Message-----
> > From: tom mcclintock [SMTP:tomm@mgcap.com]
> > Sent: Wednesday, October 20, 1999 11:42 PM
> > To: Fish, David
> > Subject: Re: Rip Off display of vectors question
> >
> > David:
> >
> > I finally took a look at Rip Off as it is displayed in Retrocade, and
> > you are exactly correct - I'm missing the high intensity vectors.
> >
> > Would you mind being a little more specific in terms of possible
> > problems? I'm not too technically proficient on the Cinematronics
> > games, but what would a control bit for INTENSITY be located on the
> > board? Also, when you refer to a Keltron, do you mean just the HV
> > section, or the entire monitor PCB?
> >
> > Sorry for asking a bunch of questions. I have access to a few spare
> > parts, and I just want the game to work :)
> >
> >
> > tom
> >
> >
> > "Fish, David" wrote:
> > >
> > > <snip>
> > > >Fired the game up
> > > >and it plays. All except for one thing. I am missing several vectors
> > > >during gameplay. Parts of my tank are missing, parts of the enemies
> > are
> > > >missing, and none of the missile or gun traces show up. The game still
> > > >plays and recognizes all inputs and actions.
> > >
> > > It sounds like you might be missing the high intensity vectors. Are all
> > > the vectors on the screen at a single intensity level? Try cranking up
> > > the brightness (intensity?) pot on the monitors PCB. What happens?
> > > If the missing lines don't show up it could be either a 'stuck'
> > INTENSITY
> > > control bit on the CPU board, a pix tube on it's way out or a problem
> > > with the Hi-V supply (probably a Keltron).
> > >
> > > Dave
Received on Thu Oct 21 09:57:06 1999