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.
Great manual very clear copied. You are making an incredible job. I appreciate a lot the rapidity and your efficiency. Thanks a lot
Text excerpt from page 86 (click to view)
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7.1.2 Protection Circuit
DC detection
A
Detection method
XPROTECT port (A/D)R397: 56 K-ohms Less than 0.6-0.8 Vdd 2.8 sec after Mute: On Speaker Relay: Off Shifting to STBY after 3 sec "AMP ERR" flashes for 3 sec Hold the STANDBY key pressed for 10 sec. The unit will recover if the duration of detection is 3 sec or less.
Detection start time Process
Display Recovery Remarks
B
Overload detection
Detection method
XPROTECT port (A/D)R363: 27 K-ohms 0.4-0.6 Vdd 2.8 sec after Mute: On Speaker Relay: Off Shifting to STBY after 3 sec "OVERLOAD" flashes for 3 sec Press the STANDBY key.
Detection start time Process
C
Display Recovery Remarks
Fan (temperature) and short-circuit of the power supply circuit
Detection method
XPROTECT port (A/D) 0.4 Vdd or less 1.0 sec after Mute: On Speaker Relay: Off Shifting to STBY No display Hold the STANDBY key pressed for 10 sec.
Detection start time Process
D
Display Recovery Remarks
Fan stop
Detection method
E
XPROTECT port (A/D) 0.4 Vdd or less 1.0 sec after Mute: On Speaker Relay: Off Shifting to STBY No display Hold the STANDBY key pressed for 10 sec.
