- #PROTEK 506 SERVICE MANUAL HOW TO#
- #PROTEK 506 SERVICE MANUAL DRIVER#
- #PROTEK 506 SERVICE MANUAL MANUAL#
So, the two resistors are the ones on the right of the ckt diagram that are inline with the Y plates and in parallel with a couple of inductors. Please be safe!! Ideally, the power supply caps should be discharged and you should try to work with one hand and the other behind your back (at least that is what they taught us in EE lab 15 yrs ago ) So anyway I think it'd be worth testing a couple of key resistors and diodes and also the transistors in the bottom half of the vertical amp (I am assuming, btw, that Y- corresponds to the lower half of the screen.)
#PROTEK 506 SERVICE MANUAL MANUAL#
Life is a bit harder since the svc manual doesn't show proper waveforms at these points.ītw, do you have access to another scope? Ideally we'd want to try and isolate the various circuits within but not sure if that is going to be fruitful. and at least a subset of circuits at least in my view - I still think the trace is telling us that the bottom 'half' of the vertical amp is wonky. So, we've isolated down to the block level for sure. Particularly the sort of repeating pattern for 2mS and 5mS. Not a big deal, no need to fix that (now or ever, probably). I'm assuming it is just out of adjustment somewhat. The mid point for trace position (ie, the balance between the top and bottom halves of the vertical amp) is adjustable as far as I am aware. When we get to measuring components in a little while, we'll play it safe and test components in circuit with power unplugged and machine off and see if we turn up anything.ītw, even though the trace goes wonky at slightly above the halfway point on the screen I still believe it is the bottom 'half' of the circuit with the problem. so that proves there *is* voltage applied to Y- though it is erratic and not very related to the signal coming in from the pre-amps! The square wave shows that the top 'half' of the vertical amp is fine but whenever the preamp drives the negative half, things go bonkers. the trace itself is actually scanning down to the bottom of the screen. To me this further confirms a problem with the circuitry driving the Y- plate. The square wave displays in the upper half or 1/3rd of the screen and when you position it lower (no matter what volts/div) the trace goes haywire below a certain point. I am seeing something very similar to what I was expecting, actually. Since the position of the beam on the screen is telling you precisely what the voltages are on the Y+/Y-, X+/X- plates we will take advantage of that to see if we can get any sense of what component(s) might be failing.įantastic video - nice work. That'll narrow us down from block to circuit (following the methodology of that troubleshooting manual)Īfter you do these tests I have another test I want us to do, to see if we can get a clearer picture of what the trace looks like and maybe get a sense of what components might be failing.
#PROTEK 506 SERVICE MANUAL DRIVER#
I'm hoping this will further verify that the problem is in the vertical amp Y- plate driver circuitry. a position on the screen where the top half of the square wave is ok and the bottom half is wonky (adjust volts/div to have the trace take up the whole screen if you want) the trace on the lower part of the screen where it is all wonky the trace in the top half where it looks like a normal square wave When you film, see if you can reposition the trace and film 20 seconds EACH of: I forgot to ask how much you know about using 'scopes.
#PROTEK 506 SERVICE MANUAL HOW TO#
Sorry if you know how to do all this already. Set it to trigger off of INT (internal, ie, trigger off the waveform being displayed) and using the AUTO trigger to make sure the square wave looks "still" on the screen. Set the position and volts/div so that the trace is taking up 1/3 to 1/2 of the screen and showing a normal square wave.ģ. Make sure you have the time/div knob set to where you can clearly see the square wave - it's period should be taking up about 2 of the major divisions on the screen.Ģ. That will help me see exactly what the trace looks like without any additional effects from the position knob.ġ. Now that we're really diving in, whenever you film the trace behaving a particular way, leave the position alone and film the trace for say 10-20 seconds. PPS: when you run the suggested tests above.