I was very glad recieving the service manal from You. Additionaly very fast. Extremaly nice servicing. Thanks very mach! Now my GX-220 working better, than it was made. Alexander from Moscow, Russia/
Sweet! I won the item on eBay and couldn't adjust the geometry or even keep a steady picure. This guide has the full schematics (not available anywhere else as far as I could tell), and was a bargain for the wealth of knowledge it contains. I hooked it up to my testing equipment, tweaked a few potentiometers and got it playing videogames in no time. Thanks!
Great Manual! It contains all the wiring schematics and mechanical exploded views that are essential for service and repair. I was surprised I even found this for such an old machine. Only wish I knew of this site many years ago.
Text excerpt from page 42 (click to view)
MECHANISM TROUBLESHOOTING GUIDE
1.Deck Mechanism
A.
No Auto Rewind operates.
YES
Is output of the end sensor �H�? �H�: 3.5V or less �L�: 0.7V �1V or less
YES
NO
Is the end sensor Vcc applied at 5V?
NO
Check the Syscon power supply.
YES
Replace the end sensor.
Is voltage at both ends of the IR LED 0.8V-1.5?
NO
Replace the LED.
YES
Is the Syscon checked?
B.
No F/R operates.
YES
Is the current mode an F/R mode?
NO
Check the assembly position of the Mode S/W.
YES NO
Does the Capstan motor rotate? Is normal voltage applied at the Vcc1 and the Vcc2 of the Capstan motor?
YES
Does the T/up and the supply reel Operate?
YES
Is the Vctl terminal voltage of the Capstan Motor applied at more than 4V?
