I see your in the chopped position on the vertical. I would recommend ch 1 until you have a trace. Ch1 and ground.

Ok, I'll leave it on Channel 1. Here's a short clip of what's happening:
https://www.dropbox.com/s/rpyaycxqn71e98w/422.m4v?dl=0

 

Once you start moving the time/div switch I see nothing on the screen other than occasional flashes. Is there a very dim trace there or no trace at all? Set the trigger level control fully clockwise (freerun). Does the same happen?

 

Once you start moving the time/div switch I see nothing on the screen other than occasional flashes. Is there a very dim trace there or no trace at all? Set the trigger level control fully clockwise (freerun). Does the same happen?

Yup, does the same thing, occasional flashes of trace. Sometimes if I start at the EXT HORIZ setting of the time/div switch and turn it to the next setting(.5s) I can just see the dot sweeping by but very dimly.

 

The brightness looks reasonable in XY mode. Usually 'scopes reduce the brightness for XY mode to prevent burning the screen by a very bright stationary spot but yours seems to be doing the opposite. I can't get much further without a circuit diagram and I haven't yet found a free one.

 

The brightness looks reasonable in XY mode. Usually 'scopes reduce the brightness for XY mode to prevent burning the screen by a very bright stationary spot but yours seems to be doing the opposite. I can't get much further without a circuit diagram and I haven't yet found a free one.

It's here, under the picture thumbnail on the right of the page, 'Tektronix 422 Manual(PDF)': http://w140.com/tekwiki/wiki/422

 

If you have a spot on the screen that is a good start.
The CRT in a 422 is known to go dim with age. Sounds like you have a trigger problem.
The trace will also go dim when the TIME/DIV control is set higher than 10μs/div.

Set the scope as follows:
CH1 & CH2 VOLTS/DIV = 1
CH1 input = GND
CH2 input = GND
CHOPPED

TIME/DIV = 1mSEC

Triggering
CH 1 & 2
LEVEL = FREE RUN

You should see two bright horizontal lines if you fiddle with INTENSITY and Vertical and Horizontal POSITION controls.

I have a 422 and the service manual. I will post schematics when required.

 

If you have a spot on the screen that is a good start.
The CRT in a 422 is known to go dim with age. Sounds like you have a trigger problem.
The trace will also go dim when the TIME/DIV control is set higher than 10μs/div.

Set the scope as follows:
CH1 & CH2 VOLTS/DIV = 1
CH1 input = GND
CH2 input = GND
CHOPPED

TIME/DIV = 1mSEC

Triggering
CH 1 & 2
LEVEL = FREE RUN

You should see two bright horizontal lines if you fiddle with INTENSITY and Vertical and Horizontal POSITION controls.

I have a 422 and the service manual. I will post schematics when required.

I've set everything according to what you've said, but I'm not seeing any traces on the crt. The photo I posted with the dot(s) is with the intensity at maximum. The EXT HORIZ setting (dot) can't be seen with the intensity knob at 12o'clock. I also get an occasional sweep while rotating the time/div knob.

 

It's here, under the picture thumbnail on the right of the page, 'Tektronix 422 Manual(PDF)': http://w140.com/tekwiki/wiki/422

Excellent - ta

If you have a 'scope (other than the one that doesn't work that is) try connecting it to the 'gate out' of the '422 with the time/div set to 0.5mS/div.
You should see a square wave. Tell me the amplitude and the time high and time low, please.

 

Looks like the problem is in the SWEEP GENERATOR circuit.
You will need a working o'scope to trouble shoot this.
Any chance that you have access to another working scope?

 

Excellent - ta

If you have a 'scope (other than the one that doesn't work that is) try connecting it to the 'gate out' of the '422 with the time/div set to 0.5mS/div.
You should see a square wave. Tell me the amplitude and the time high and time low, please.

Nothing coming out of the Gate Out.

 

Looks like the problem is in the SWEEP GENERATOR circuit.
You will need a working o'scope to trouble shoot this.
Any chance that you have access to another working scope?

Two actually, a 465 and a 5441!

 

hello

Nothing coming out of the Gate Out.

Sweep generator fault confirmed.

 

Looks like the problem is in the SWEEP GENERATOR circuit.

We can't both guide the fault-finding - that would get very confusing.
It sounds like you have recent experience of the '422, so I'll leave it to you, yes?

 

Two actually, a 465 and a 5441!

How comfortable are you with following schematic drawings and probing live circuits?

 

How comfortable are you with following schematic drawings and probing live circuits?

Comfortable, been in scopes before, repaired a Telequipment and the Tek 5441 that I'm using right now. So whatever I need to do I'll do it.

 

We can't both guide the fault-finding - that would get very confusing.
It sounds like you have recent experience of the '422, so I'll leave it to you, yes?

I understand and I agree that only one person should lead the trouble-shooting. I don't mind if you have a go at it. I am quite happy to watch on the sideline. I do have many years experience fixing scopes but would like to give others the chance to expand on their knowledge. I am happy to just supervise on the side when required.

I don't have the 422 manual in front of me and will have to retrieve it from work.

 

I understand and I agree that only one person should lead the trouble-shooting. I don't mind if you have a go at it. I am quite happy to watch on the sideline. I do have many years experience fixing scopes but would like to give others the chance to expand on their knowledge. I am happy to just supervise on the side when required.

I don't have the 422 manual in front of me and will have to retrieve it from work.

Thank you both very much for taking the time to help with the 422, it's such an adorable scope(still heavy!) and I'd hate to see it end up in a parts bin.

 

I do have many years experience fixing scopes but would like to give others the chance to expand on their knowledge.

I did a lot of 'scope fixing but it was in the 70's so is going to be a bit rusty. You also have a 'reference '422 which might be useful, and a paper schematic. Over to you.

 

I'll quit. I was hoping to see a full functional checkout.

 

If you examine the SWEEP GENERATOR schematic you will see waveforms and DC operating voltages given.
You want to be able to confirm the presence or absence of these signals and voltages.
Always check supply voltages coming into the circuit as a place to begin.

If you need specific physical locations on the unit I will open my 422 and post photos for you.

Edit: It turns out I do have the 422 Manual here with me. I'll have a look at the schematics.