Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: psyclick on May 06, 2006, 06:37:25 am
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Hi all,
I've just recently got hold of an absolutely huge JAMMA cabinet that has a 28" Hantarex Polo monitor in it, and i've just about got it working ok with an ArcadeVGA video card,
However,
Following the instructions for setting up the monitor in the service manual it says I need to adjust the R/G/B cut off pots to obtain 180V on the collectors of three corresponding transistors (T2,T4 and T6) on the neck board.
I can get the 180V on the Green and Blue transistors, but the Red tops out at 165V ! the image on the monitor is pretty good but this kind of thing bothers me as there is obviously something not quite right.
I've replaced the smaller transistors (BC548B, T3 T5 and T7) which made no difference, which only leaves the main IC (LM1203) or the big power transistors (BF859, which I am unable to find as they are discontinued)
My questions then are -
Any ideas what component could be causing this ?
Anyone know of an equivalent transistor replacement for the power transistors (BF859) ?
Lastly, I've got a Cap Kit on order, which I hope will clean up any other minor wobblies :)
Neil.
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if your picture is good then don't be too concerned about the slightly low voltage,its not the lm1308n ic or the power transistors-if anything i would imagine its down to one of the small caps or one of the large load resistors on the neck card.to sum up if had not checked this voltage would you consider you had a faulty monitor
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Yes, I would do a capkit first before playing with any adjustments on the neck board.