wierd fault on a tube

[grantspain]

Just thought i would let you all know about a very strange fault i had arise on a Outrun 2 this week,i noticed the screen on player 4 off during the day so i did the usual reboot and hey presto the screen comes up although minus the red .Next i swapped the board rgb outputs,no difference so therefore monitor fault ,then i swapped the neck card for a quick fix(sanwa monitor btw) because thats where the video decoding and colour transistors are-still no joy ,now its got to be a tube gun fault.Well i swapped the tube from a naomi cab and bingo the red is back and the picture is spot on .
Now many years ago an old work mate said that sometimes dust can short the guns out,he also said that you could rectify this by turning the tube on its face and tapping the neck gently to dislodge the dust,well would you believe it-it worked a treat .Now what i am wandering is if anyone else on this forum has had the same fault and how common/rare it is?

[Doughbroz]

It's not an uncommon problem, especially with upward-facing tubes, such as in cocktail cabinets.  When there is trash shorting the neck, the symptom is usually a color gun that is stuck ON instead of a missing color.  Rejuvenating (shooting) the tube usually fixes this problem if tapping on the neck doesn't.   Once you have this problem with an upward oriented tube, use it only in a normally oriented position game.