Recently received a super gun from a member who asked me to fix it,he said it used to work but then stopped.
Here it is on my work bench, I received the super gun,power supply and rgb cable.
Plugged everything and powered on with my 19 in 1 pcb but I got a black screen with absolutely no image ,sound was working with music playing. So it appears we have proper power but more likely a problem in the rgb output,next I removed the rgb din plug from the gun and scoped the output pins.All signals were present as well as the blanking 5 volts out.
Ok so far we have rgb video, composite sync,blanking 5 volts which is good so it's got to be a problem in the scart lead. Reconnected the rgb din back to the guns 8 pin socket and started to scope the scart 21 pin plug, all signals were present except the blanking signal at pin 16 which was floating. Removed the cover and ......
As you can see the wire circled is the blanking wire which had been detached from pin 16.The weird thing is on pin 16 there's a link wire which goes to pin 8?
Pin 8 is used for rgb switching at 12 volts.
To be honest the quality of this is a mess,decided to remove all wires and redone the wiring to a better standard.
Now that is much better, I've connected the blanking wire with a 100 ohm resistor so the pin gets the correct 3 volts also there was a spare purple wire which I've soldered to pin 8 to force rgb switching. As one of the pins on the rgb socket was not used I soldered a wire on this pin to 12 volts on the 28 pin edge connector.
Reconnected everything and plugged in the 19 in 1 pcb and......
Ohhhhhhh yes
We have game,all controls and sounds and picture working perfect.
Another satisfying repair.
Here it is on my work bench, I received the super gun,power supply and rgb cable.
Plugged everything and powered on with my 19 in 1 pcb but I got a black screen with absolutely no image ,sound was working with music playing. So it appears we have proper power but more likely a problem in the rgb output,next I removed the rgb din plug from the gun and scoped the output pins.All signals were present as well as the blanking 5 volts out.
Ok so far we have rgb video, composite sync,blanking 5 volts which is good so it's got to be a problem in the scart lead. Reconnected the rgb din back to the guns 8 pin socket and started to scope the scart 21 pin plug, all signals were present except the blanking signal at pin 16 which was floating. Removed the cover and ......
As you can see the wire circled is the blanking wire which had been detached from pin 16.The weird thing is on pin 16 there's a link wire which goes to pin 8?
Pin 8 is used for rgb switching at 12 volts.
To be honest the quality of this is a mess,decided to remove all wires and redone the wiring to a better standard.
Now that is much better, I've connected the blanking wire with a 100 ohm resistor so the pin gets the correct 3 volts also there was a spare purple wire which I've soldered to pin 8 to force rgb switching. As one of the pins on the rgb socket was not used I soldered a wire on this pin to 12 volts on the 28 pin edge connector.
Reconnected everything and plugged in the 19 in 1 pcb and......
Ohhhhhhh yes
We have game,all controls and sounds and picture working perfect.
Another satisfying repair.
