ChildOfCv Posted April 12, 2021 Share Posted April 12, 2021 (edited) You had color in your other videos though. But you also had digital graphics corruption. Pins 1 and 18 of the 1889 should have a 4.43MHz sine wave on them. Edited April 12, 2021 by ChildOfCv Quote Link to comment Share on other sites More sharing options...
hyuma Posted April 12, 2021 Author Share Posted April 12, 2021 You had color in your other videos though. But you also had digital graphics corruption. Pins 1 and 18 of the 1889 should have a 4.43MHz sine wave on them.I haven't nothing similar on that pins and also I replaced the oscillator with the same model and the situation didn't changed at all.. I tested 3 different new oscillator and still don't know why I haven't the 4.3mhz wave.. Inviato dal mio CLT-L09 utilizzando Tapatalk Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted April 12, 2021 Share Posted April 12, 2021 17 minutes ago, hyuma said: I haven't nothing similar on that pins and also I replaced the oscillator with the same model and the situation didn't changed at all.. I tested 3 different new oscillator and still don't know why I haven't the 4.3mhz wave.. Make sure there is +12V at Q20 pin 2. This should turn the transistor off so that it doesn't interfere with the oscillator. Q20 pin 3 should be much less than 12V. Q23 pin 2 should be about 4.3V. Q23 pin 1 should be around 3.9V. Q23 pin 3 should be around 7.4V. All voltages taken with the black lead on ground. Quote Link to comment Share on other sites More sharing options...
hyuma Posted April 13, 2021 Author Share Posted April 13, 2021 Make sure there is +12V at Q20 pin 2. This should turn the transistor off so that it doesn't interfere with the oscillator. Q20 pin 3 should be much less than 12V. Q23 pin 2 should be about 4.3V. Q23 pin 1 should be around 3.9V. Q23 pin 3 should be around 7.4V. All voltages taken with the black lead on ground.Q20: Base: 11.17vEmitter: 11.93vCollector 11.90v Q23: Base: 4.24vEmitter: 3.50vCollector: 7.86v Inviato dal mio CLT-L09 utilizzando Tapatalk Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted April 13, 2021 Share Posted April 13, 2021 (edited) 1 hour ago, hyuma said: Q20: Base: 11.17v Emitter: 11.93v Collector 11.90v Q20 is wrong. What's the voltage on the other side of R137? And do you have anything plugged into the expansion module? Edited April 13, 2021 by ChildOfCv Quote Link to comment Share on other sites More sharing options...
hyuma Posted April 13, 2021 Author Share Posted April 13, 2021 Q20 is wrong. What's the voltage on the other side of R137? And do you have anything plugged into the expansion module?Voltage is about 5.45v. And no, I don't have nothing plugged on expansion moduleInviato dal mio CLT-L09 utilizzando Tapatalk Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted April 13, 2021 Share Posted April 13, 2021 6 hours ago, hyuma said: Voltage is about 5.45v. And no, I don't have nothing plugged on expansion module Inviato dal mio CLT-L09 utilizzando Tapatalk That's way too low then. The control you're reading now activates external video and has a pull-up resistor R160 to hold it at 12V until something pulls it down. The external video enable pin is 32 (bottom side, second from right) at the expansion slot. Make sure R160 is 12V on one side. Really, it should be 12V on both sides, but you said you're reading 5.4 instead. If you can't find a reason for the external video to be loaded down (solder bridge, cracked solder joint, etc) then try removing U30 to see if it improves. If not, put it back and remove U31 and repeat the voltage test. Quote Link to comment Share on other sites More sharing options...
hyuma Posted April 13, 2021 Author Share Posted April 13, 2021 That's way too low then. The control you're reading now activates external video and has a pull-up resistor R160 to hold it at 12V until something pulls it down. The external video enable pin is 32 (bottom side, second from right) at the expansion slot. Make sure R160 is 12V on one side. Really, it should be 12V on both sides, but you said you're reading 5.4 instead. If you can't find a reason for the external video to be loaded down (solder bridge, cracked solder joint, etc) then try removing U30 to see if it improves. If not, put it back and remove U31 and repeat the voltage test.I have 5.4v on one side of R137... I never measured yet R160Inviato dal mio CLT-L09 utilizzando Tapatalk Quote Link to comment Share on other sites More sharing options...
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