Starting a thread on my troubleshooting of my G07 in my Defender to figure out my Red gun problem.
I've done the following:
- Swapped Red & Green wires on Defender PCB to see if that was the cause, no change, Red gun still dead.
- Swapped Red & Green wires on the neck PCB of the G07, no change, Red gun still dead. Proved my signals from my G07 main board are good however as the "green" was visible when red was told to come on in test patterns.
- Connected Apple IIGS monitor to Defender PCB, picture is good, proves Defender is ok.
- Connected Fluke ScopeMeter to Green and Red wires on neck PCB, signals looks the same when displaying colour bars.
- Connected Fluke ScopeMeter to Green Cathode (GK) and Red Cathode on neck PCB, signals looks the same when displaying colour bars. Leads me the believe the Red gun is actually dead.
Ordered up a B&K 490A Rejuvinator, arrived today. Connected to monitor, all guns tested in the "Good" range and no leakage or shorts.
- As a last resort, I swapped the Neck transistors X102 and X103 just "in case". Powered up unit, problem still persisted, no red.
- Connected Fluke ScopeMeter to Green and Red wires on neck PCB, signals looks the same when displaying colour bars.
- Connected Fluke ScopeMeter to Green Cathode (GK) and Red Cathode on neck PCB, signals looks the same when displaying colour bars.
- Still leads me the believe the Red gun is actually dead...
So now I'm stumped... the 490A thinks the Red gun is good but still no red on the monitor. Blue and Green are fine.
My next step once I've let the monitor sit for a while and again discharge it, will be to lift the two resistors leading the Gk & Rk and jumper the over each other so the Red is feeding the Green Gun and the Green is feeding the Red Gun. Just to totally eliminate the neck PCB.
Will update once this last test is done but if anyone has a suggestion, please feel free.
Cheers
Tim
I've done the following:
- Swapped Red & Green wires on Defender PCB to see if that was the cause, no change, Red gun still dead.
- Swapped Red & Green wires on the neck PCB of the G07, no change, Red gun still dead. Proved my signals from my G07 main board are good however as the "green" was visible when red was told to come on in test patterns.
- Connected Apple IIGS monitor to Defender PCB, picture is good, proves Defender is ok.
- Connected Fluke ScopeMeter to Green and Red wires on neck PCB, signals looks the same when displaying colour bars.
- Connected Fluke ScopeMeter to Green Cathode (GK) and Red Cathode on neck PCB, signals looks the same when displaying colour bars. Leads me the believe the Red gun is actually dead.
Ordered up a B&K 490A Rejuvinator, arrived today. Connected to monitor, all guns tested in the "Good" range and no leakage or shorts.
- As a last resort, I swapped the Neck transistors X102 and X103 just "in case". Powered up unit, problem still persisted, no red.
- Connected Fluke ScopeMeter to Green and Red wires on neck PCB, signals looks the same when displaying colour bars.
- Connected Fluke ScopeMeter to Green Cathode (GK) and Red Cathode on neck PCB, signals looks the same when displaying colour bars.
- Still leads me the believe the Red gun is actually dead...
So now I'm stumped... the 490A thinks the Red gun is good but still no red on the monitor. Blue and Green are fine.
My next step once I've let the monitor sit for a while and again discharge it, will be to lift the two resistors leading the Gk & Rk and jumper the over each other so the Red is feeding the Green Gun and the Green is feeding the Red Gun. Just to totally eliminate the neck PCB.
Will update once this last test is done but if anyone has a suggestion, please feel free.
Cheers
Tim


