robotron sound - i have none, but weird sound PCB voltages...

Klassic

Member
Joined
Dec 9, 2006
Messages
597
Reaction score
6
Location
Boynton Beach, Florida
robotron sound - i have none, but weird sound PCB voltages...

game works now, but is new to me, so i don't have much of a history with it. currently, last issue i have is no sound. the weird part, is the sound board voltages are:

+13.8
ground
+13.14
+13.6.

are they supposed to be +5, ground, -12, +12, going from TP1 thru TP4?

everything else appears to be fine. fuses, power supply voltages, game play, etc...
 
From the schematics... it looks like TP1 - TP4 should be...
+12v (unregulated)
-12v (unregulated)
GND
+5v
 
thanks, jeff...ok, that explains those stupid original results...

checked correctly, i'm at:

+.65
-12.8
ground
+.53


cap it? at least the numbers now make some sense. ha...
 
Last edited:
Check fuse F2 on that sound board. If it's good, then the bridge rectifier BR1 is probably bad.

[edit]
Actually... if F2 is good... you may just have some cold solder joints on J1(the 9-pin connector near the corner of the sound board). Definitely check that before you go desoldering BR1 to check it.
 
Last edited:
thank you. both fuses checked out good last night (removed from PCB), but i went ahead and just now replaced them and cleaned the fuse holder on F2. powered up, now i have sound. guessing just a poor connection from sitting for years.

it was just a fuse...dammit. i usually don't post fuse questions...ha ha.



Check fuse F2 on that sound board. If it's good, then the bridge rectifier BR1 is probably bad.

[edit]
Actually... if F2 is good... you may just have some cold solder joints on J1(the 9-pin connector near the corner of the sound board). Definitely check that before you go desoldering BR1 to check it.
 
Last edited:
Back
Top Bottom