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Main => Monitor/Video Forum => Topic started by: Magnet_Eye on January 19, 2006, 02:22:50 am

Title: help with intermittent monitor problem
Post by: Magnet_Eye on January 19, 2006, 02:22:50 am
Hi, i have a cab with a CPS2 system running Dark Stalkers. It has a 25" Pentranic monitor. One day I when i turned the machine on, the monitor was black. I don't know why. I left it alone and a couple weeks later opened her up, and kinda of wiggled wires to be sure nothing came loose, etc. When I turned it on VOILA! It worked fine. Then one day a few weeks later, the same thing the next time I turned her on. Black. I checked the wires again, but no luck this time. I can't get it to have a screen. It is getting power, the neck has an orange glow, but there's no picture. The game is working, you can here the sound. Any ideas?

Thanks.
Title: Re: help with intermittent monitor problem
Post by: grantspain on January 19, 2006, 05:28:08 am
If you got an orange glow from the neck its a good sign,when you turn on your cab turn up the screen volts on the lopti,if you then get a blank raster with flyback lines then you could then look at your signal in for colour(is it rgb or vga),this is likely to be a bad connection.
The only other problem i have had with pentranics losing signal is on the neck board there is a LM1203N IC this controls the colours,if this goes faulty you get tube heaters but no picture.
Title: Re: help with intermittent monitor problem
Post by: fredster on January 19, 2006, 05:33:26 pm
1) Loose connection at the monitor connector from PCB.  (check sync and ground)
2) Xray protection circuit failure (cap failure usually)
3) Your PCB is bad and causing the problem (bad connection at slider connector)
4) Loose power wires



Title: Re: help with intermittent monitor problem
Post by: Magnet_Eye on May 25, 2006, 09:42:49 pm
ok, i hadn't had time to mess with it until today.

When i turn the adjustments (horz., vert., brightness, contrast, etc) I get a thin blue horizontal line on screen. the monitor powers on fine and all. i'm wondering if it could be the game itself? I can hear the game, and everything else seems to work... just no picture.

wish i had a jamma pcb to swap in there to find out. ugh!

so, if anyone has any ideas. i still can't figure out what's goign on. i lack the knowledge.

i appreciate it.

Title: Re: help with intermittent monitor problem
Post by: grantspain on May 26, 2006, 02:30:09 pm
if its the pentranic i think it is then they suffered frame collapse,i will post you 2morrow the chip which is faulty(burn up big time),also you have to change a cap and check a diode for damage
Title: Re: help with intermittent monitor problem
Post by: Magnet_Eye on May 27, 2006, 03:47:47 am
if its the pentranic i think it is then they suffered frame collapse,i will post you 2morrow the chip which is faulty(burn up big time),also you have to change a cap and check a diode for damage

ok. thanks!
Title: Re: help with intermittent monitor problem
Post by: grantspain on May 27, 2006, 11:02:15 am
its been nearly two years since i worked on pentranics so you will have forgive me as i forget the ic position,the ic is a tda1175p-it has a gull wing type heat shield on the top of it,if you replace this ic you will need lots of heat conductive grease,also this was a pig of a job as the track always damaged badly even with the best soldering skills,the cap is the only one thats next to the chip and in4001 diode is next to it-the best thing you could do is send me a picture of your chassis as for all i know at the moment we could be talking about two different chassis-anyway the original fault with the chassis i describe is a frame lapover at the top of the screen progressing to frame collapse