an arbitrary waveform generator NUMBER_TOKEN channel oscilloscope logic analyzer it has a multimeter and a power supply all built into this one device this was donated to the channel by a lovely viewer here in town tyler and i've had it for quite a while and i actually haven't used it yet i'm ashamed to say and i finally realized that this might be able to allow me to test the crt because of the function generator capability of it i can generate the exact signal that the monitor needs for the horizontal drive but on top of that it's also a two-channel oscilloscope which is what you see on screen here which allows me to easily show this stuff on video versus filming my rygall scope which doesn't have video output because i have one of the lower end rygalls that does not have vga now the rygall some people are going to probably say which is sitting up there on the top has some software you can run and over ethernet or usb also get a representation of all the controls but i found that software to be unreliable difficult to use and really slow this virtual bench software on the other hand is uh not bad i have to say it really isn't bad the waveform update rate is pretty good and so i'll probably be using this more in the future anyhow channel one here in red this is the signal actually coming off of the video card and as you can see right here it's uh that's too short because the documentation is quite specific on the length of the pulse it needs and looking down here further in the documentation we can see the schematics for the monitor and what i did to figure out that the pulse was just not good enough is i started measuring this is the horizontal drive input these are the transistors that start to amplify the signal and then this is the primary horizontal output drive transistor which ends up creating this waveform here NUMBER_TOKEN volts peak to peak which i think this yeah feeds into the flyback transformer this generates the high voltage and also feeds off somewhere to the yoke what would happen is when i power up the monitor and i'd be checking these waveforms like this one right here six volts peak to beak it would show up for a second and then it would collapse and the same with this output one so the monitor would never generate any high voltage now i don't know for sure if it's still the flyback that's bad it could be but i need to at least get the correct signal into this thing first just to make sure that it is not a problem with the signaling and to help isolate the particular issue now the funny thing is is this board is the motorola board as we've talked about there are two boards there's the motorola one this one and there's also one made by rca and the specs for that are further down in this document in fact here they are right here rotate this back so we can read this properly so here's the rca input and take a look at this the horizontal input is good from NUMBER_TOKEN to NUMBER_TOKEN so it's almost like if this were the rca board it would actually work off this compact border potentially right off the cga port but the motorola one is much fussier and needs that specific length signal that it cannot work down to four microseconds
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