need help with a fault please anyone

david2010 · Post by **david2010** » Sat Apr 24, 2010 2:55 pm

i have a global machine called A KNIGHTS TRAIL and i have a slight fault.

the fault is the speaker has a buzzing interferance comein out of it and i dont no wot it is doin my head in.

anyone with an answer would be a very great help.

many thanks david

jblackbean20010 · Post by **jblackbean20010** » Thu Jun 03, 2010 12:12 pm

Hiya,

Not to upto speed on machines but i would try to turn the volume up or down and see if it helps also check the speaker within the machine is not to loose, if it is loose try and tighten it but not too much.

James

stewy · Post by **stewy** » Thu Jun 03, 2010 3:46 pm

I would point out that there is often no cause to worry about a slight buzz coming from the speaker on most m/c's. What does it sound like during gameplay? It micht be worth checking that the speaker is properly connected at both ends.

reelman · Post by **reelman** » Thu Jun 03, 2010 9:36 pm

The diagnosis to your problem can be spelt in one of two ways "Global" or "Maygay"
This is an inherant trait of their design. It's efectively "feedback" from the lamp mattrix and I'm afraid there's nought you can do about it.
You shouldn't notice the "hum" too much, if at all, during play, but only when the the machine is in its out of credit display mode i.e. not being played.

GES1407 · Post by **GES1407** » Fri Jun 04, 2010 12:20 am

Hi, from my limited experience it could be an earth problem, have you checked all the earthing points? its usually a power problem, like its picking up the noise from a power source like the transformer or a faulty board component not smoothing the current out, the rectification circuit on my machine is toast & when its charging up the big capacitor on the board (Eclipse board) it crackles & hums out of the speaker until the capacitor is charged & i've reset the machine or turned it on & off then it plays fine, as yours is a global it might have the eclipse board from what i understand, at the bottom right of the board looked at from inside machine where its mounted, thats where the dc rectification happens & if theres a prob there it could be your prob, mine has a split in half zener diode & a blown off the board resistor, but luckily it still works with a bit of patience every turn on, but with maygay/global machine it could be anything! but from what you say i'd be looking toward the power circuit & things to do with it