TEKTRONIX 2213A CRO Oscilloscope - XY Mode Issue - Only half a circle

[BTO]

I also had a half moon on my Tek2225, see this thread.
In the end it appeared to be a loose connection.
Maybe that thread gives you some pointers.

I had a look at your issue.
My one appears to be identical, Almost.
Your semi circle even appears on the same side.
the only difference is, You adjusted the circle with Phase shifting, i'm doing with Frequency shifting.. but, that doesn't matter too much for the problem.

[BlownUpCapacitor]

I had another look at schematics again. Try fiddling with R738. It's the x-axis offset pot. Remember to back its original setting with a marker or something. If that doesn;t rectify the issue, reset it and follow the following steps.

Probe pin 5 of P9705. Does it resemble the input signal from ch1?

If not, probe TP350. Does it resemble the input signal?

If not, desolder Q739 and power up the unit in X-Y mode without the transistor. While this transistor is out of circuit, do not switch into any other modes other than X-Y as this may damage the scope. If the problem solved?

If not, resolder Q739 back in, or just replace it with generic 2N3904, then probe the emitters of U350E and U350D using differential probing. DO NOT CONNECT A GROUND LEAD TO ANY OF THESE POINT!!! Does it resemble the input signal?

If not, probe the bases of Q302 and Q303 using differential probing. DO NOT CONNECT A GROUND LEAD TO ANY OF THESE POINT!!! Does it resemble the input signal?

Report back.

[BTO]

I had another look at schematics again. Try fiddling with R738. It's the x-axis offset pot. Remember to back its original setting with a marker or something. If that doesn;t rectify the issue, reset it and follow the following steps.

Probe pin 5 of P9705. Does it resemble the input signal from ch1?

If not, probe TP350. Does it resemble the input signal?

If not, desolder Q739 and power up the unit in X-Y mode without the transistor. While this transistor is out of circuit, do not switch into any other modes other than X-Y as this may damage the scope. If the problem solved?

If not, resolder Q739 back in, or just replace it with generic 2N3904, then probe the emitters of U350E and U350D using differential probing. DO NOT CONNECT A GROUND LEAD TO ANY OF THESE POINT!!! Does it resemble the input signal?

If not, probe the bases of Q302 and Q303 using differential probing. DO NOT CONNECT A GROUND LEAD TO ANY OF THESE POINT!!! Does it resemble the input signal?

Report back.

FIRSTLY
Shit... I blew up my scope 

No... Not really .
Yes i understand the dangers of mains referencing the ground reference of the scope......   DON'T WORRY ABOUT IT. I'm aware of it.
- Now i do not have a differential probe
- However.. i do have a handheld Hantek Scope which is "Floating", i can charge it up on Battery power and use it
to conduct the tests.

FOR THE BENEFIT OF NEWBIES READING THIS AND WONDERING
"What the Hell are they on about ?"

TRAP FOR YOUNG PLAYERS


So.. Update, Young Riley will be coming next week on Saturday
Until then i'll have a peek inside, but i do want to wait for him until we sink our teeth in

[BlownUpCapacitor]

You don't need to use a handheld floating scope. Just use differential probing, by using two conventional probes.

On a scope like a 2235, set the cert mode to "ADD" and set channel two to "INVERT". This will make a differential amp. So you can use a ground-referenced scope.

Look at this video: https://youtu.be/DgYGRtkd9Vs?si=ZeNDvT2toklw6CCg&t=559

You can use a good high bandwidth bench top scope instead of a cheap hantek here.

[BTO]

You don't need to use a handheld floating scope. Just use differential probing, by using two conventional probes.

On a scope like a 2235, set the cert mode to "ADD" and set channel two to "INVERT". This will make a differential amp. So you can use a ground-referenced scope.

Look at this video: https://youtu.be/DgYGRtkd9Vs?si=ZeNDvT2toklw6CCg&t=559

You can use a good high bandwidth bench top scope instead of a cheap hantek here.

well, i do have a high bandwidth scope, Rigol MSO5000 Series (350MHz), Although.. I'd rather not use it in this instance.
is there anything inherently wrong with using the hantek , Just in case.
at the end of the day it is a floating scope.
If it's not earth referenced, I don't see the issue with it.
Worse case scenario, something happens and the hantek gets sacrificed.

[BTO]

OK, I'm back
With a great degree of difficulty, I got the C.R.O. Open.

AS ADVICE FOR ANYONE ATTEMPTING THIS
1. There is a screw on side of the chasis (take that out)
2. Take off the Back Cover
3. Initially you don't need to worry about removing the front panel cover or buttons and knobs
4. The 2 hinges that hold up the legs HAVE NOTHING TO DO WITH OPENING THE SCOPE.

The Housing will Slide down and out the back of it,  But it will require some convincing because the friction (in my case, Caught on around
half way making me think i missed a screw.

Once opened, Here is what it looks like

[BTO]

After looking at schematics, check the following transistors:

Q732
Q737
Q742
Q743

They amplify the X-axis signal from CH1.

Don't pull them out. Use another scope to trace the signal from CH1 in X-Y mode. Follow the schematic on page 159 here https://w140.com/tekwiki/images/e/e5/070-4733-00.pdf

Follow the signal until it looks "wrong", maybe the wave is cut in half, or it's out of phase.

So.. I was looking for those Tranny's that you stated.
AND THEN I SAW THIS and then i looked closer with my video microscope
41 - is what i spotted first
42 - a bit of a closer look
33  and 34 are video scope views

so... We have CRACKED JOINTS

I sucked up the old solder with Solder wick and Re Soldered the Joints
then restarted the scope, still get the same result,  XY Still doesn't work, 
But YT Does

I've also noticed that If i feed in a Signal (say sine wave) 1kHz  that's fine, But given this is a 60MHz scope.
i should be able to feed in up to 60MHz and still be able to stretch out the signal (or.. Zoom in) and be able to easily see the waveform,
However i can't. Even at 10MHz you can't zoom in and see the waveform as a single AC Line.

[BTO]

After looking at schematics, check the following transistors:

Q732
Q737
Q742
Q743

They amplify the X-axis signal from CH1.

Don't pull them out. Use another scope to trace the signal from CH1 in X-Y mode. Follow the schematic on page 159 here https://w140.com/tekwiki/images/e/e5/070-4733-00.pdf

Follow the signal until it looks "wrong", maybe the wave is cut in half, or it's out of phase.

Now..
1. I couldn't find those Tranny's yet that you listed, I've looked on the mainboard , it's not there.
Now there are 2 others boards, A VERTICAL (which forms the board for the knobs ) and A HORIZONTAL (which appears to be
for the Op Amp and controls and calibrations of controls)  I took a few pictures of this

On these boards, the first thing i encounter after the control knob is (What i believe is A TIMING CAPACITOR)

Pretty cool.... It's a Tektronix Cap 0.019uF , 600V  (Hard to Find)
Now, one of these caps is questionable the other seem highly bloated , I'm inclined to replace them.
it's the Ch2 cap that seems bloated the most.

[BTO]

After looking at schematics, check the following transistors:

Q732
Q737
Q742
Q743

They amplify the X-axis signal from CH1.

Don't pull them out. Use another scope to trace the signal from CH1 in X-Y mode. Follow the schematic on page 159 here https://w140.com/tekwiki/images/e/e5/070-4733-00.pdf

Follow the signal until it looks "wrong", maybe the wave is cut in half, or it's out of phase.

Here is the Channel 1 Cap (Picture 37)
and 38 is the Channel 2 Cap

Now in the process of looking around (Picture 35) shows that i noticed voltage readings coming out of the PSU.
so i decided to test them with a DMM, they were
  30    V DC
100    V DC
    8.6 V DC
    5    V DC
  - 8.6 V DC
They all test pretty much spot on.

[bdunham7]

Pretty cool.... It's a Tektronix Cap 0.019uF , 600V  (Hard to Find)
Now, one of these caps is questionable the other seem highly bloated , I'm inclined to replace them.
it's the Ch2 cap that seems bloated the most.

Those are not electrolytic caps and are very unlikely to be bad.  Besides, they are simply the AC blocking capacitors and completely irrelevant if you are using DC coupling.

[BlownUpCapacitor]

That blown capacitor implies that someone overloaded the input and damaged something. Most likely in the attenuator.

[BTO]

Pretty cool.... It's a Tektronix Cap 0.019uF , 600V  (Hard to Find)
Now, one of these caps is questionable the other seem highly bloated , I'm inclined to replace them.
it's the Ch2 cap that seems bloated the most.

Those are not electrolytic caps and are very unlikely to be bad.  Besides, they are simply the AC blocking capacitors and completely irrelevant if you are using DC coupling.

I'm confused
1. the rating on them is 0.019uF   which to me suggest a capacitor
2. Granted i have NEVER in my life seen a Tektronix Capacitor
3. when i look up the part , it's called a Timing CAPACITOR
4. you yourself called it AC Blocking Capacitor

so.. How is it not a capacitor ?

[BTO]

That blown capacitor implies that someone overloaded the input and damaged something. Most likely in the attenuator.

i wouldn't say it's BLOWN but i would say it's bulging.
But, ok, i'll keep the attenuator in mind

i now have to figure out how to remove the boards out of the scope, once i do that i have a look for that transistor
that you were referring to

[bdunham7]

I'm confused
1. the rating on them is 0.019uF   which to me suggest a capacitor
2. Granted i have NEVER in my life seen a Tektronix Capacitor
3. when i look up the part , it's called a Timing CAPACITOR
4. you yourself called it AC Blocking Capacitor

so.. How is it not a capacitor ?

1.  Yes
2.  Not unusual in this era to have Tek or Fluke or HP part labels on seemingly ordinary components.
3.  Where are you seeing "Timing Capacitor"?  These appear to me to be C2 and C52 on the attenuator board.
4.  Yes, according to the schematic, these are the AC blocking capacitors.  0.019uF for the early s/n, 0.022uF for the later ones. 

I didn't say it wasn't a capacitor, I said it isn't an electrolytic capacitor.  It's listed as a "plastic" capacitor, which probably means polypropylene but IDK for sure.  The later model ones do look like PP, yours are in a can so it is hard to tell.  The bottom line is that they don't have the same common failure modes that an electrolytic cap might have and in any case, the scope would still work properly (in DC-coupled mode) even if the capacitors in question were shorted, open, missing or in any other state you could think of.

[BTO]

I'm confused
1. the rating on them is 0.019uF   which to me suggest a capacitor
2. Granted i have NEVER in my life seen a Tektronix Capacitor
3. when i look up the part , it's called a Timing CAPACITOR
4. you yourself called it AC Blocking Capacitor

so.. How is it not a capacitor ?

1.  Yes
2.  Not unusual in this era to have Tek or Fluke or HP part labels on seemingly ordinary components.
3.  Where are you seeing "Timing Capacitor"?  These appear to me to be C2 and C52 on the attenuator board.
4.  Yes, according to the schematic, these are the AC blocking capacitors.  0.019uF for the early s/n, 0.022uF for the later ones. 

I didn't say it wasn't a capacitor, I said it isn't an electrolytic capacitor.  It's listed as a "plastic" capacitor, which probably means polypropylene but IDK for sure.  The later model ones do look like PP, yours are in a can so it is hard to tell.  The bottom line is that they don't have the same common failure modes that an electrolytic cap might have and in any case, the scope would still work properly (in DC-coupled mode) even if the capacitors in question were shorted, open, missing or in any other state you could think of.

2 Quick points

You didn't say it WASN'T a capacitor.
No problem
I however didn't say it WAS an electrolytic 

Where did i see, TIMING CAPACITOR ?
here...
https://www.ebay.com/itm/224560230256

They don't look electrolytic and i first thought Axial.
it has 1 leg going into the usual place and the other leg seems to be on the can

I'm going to try and separate the 3 boards and check whatever i can and follow the schematic and then have a look around for thos Tranny's.

thus far i have the housing off and can see the markings on the bottom of the Main Board, thos tranny's are not there
but i didn't expect them to be either
so... the Search continues

[BlownUpCapacitor]

These "plastic capacitors" are typically used for timing applications in Tek instruments. In fact, all of the horizontal timing circuits in all the oscilloscopes I have (that are Tektronix) use this timing capacitor idea.

I have included an example of a Timing Capacitor in my 7B80 horizontal sweep plug-in.

And on to you not being able to find the transistor, they are hidden away inside the metal construction of the horizontal sweep camshaft.

I have attached a photoshopped image of the diagram for the A4 timing board. The transistors of suspect are highlighted in red.

Do not replace the "timing capacitors" on the A4 board. Those capacitors are matched and are highly unlikely to fail.

These "plastic capacitors" can usually be replaced with new modern polyprop caps.

[BTO]

These "plastic capacitors" are typically used for timing applications in Tek instruments. In fact, all of the horizontal timing circuits in all the oscilloscopes I have (that are Tektronix) use this timing capacitor idea.

I have included an example of a Timing Capacitor in my 7B80 horizontal sweep plug-in.

And on to you not being able to find the transistor, they are hidden away inside the metal construction of the horizontal sweep camshaft.

I have attached a photoshopped image of the diagram for the A4 timing board. The transistors of suspect are highlighted in red.

Do not replace the "timing capacitors" on the A4 board. Those capacitors are matched and are highly unlikely to fail.

These "plastic capacitors" can usually be replaced with new modern polyprop caps.

"And on to you not being able to find the transistor, they are hidden away inside the metal construction of the horizontal sweep camshaft."
LOL.....OF COURSE THEY ARE !, I mean.. why wouldn't they be ?  what sane person would put them in an easily accessible location  LOL

"Do not replace the "timing capacitors" on the A4 board. Those capacitors are matched and are highly unlikely to fail."
Understood

"I have attached a photoshopped image of the diagram for the A4 timing board. The transistors of suspect are highlighted in red."
I owe you a cup of coffee LOL, thank you

[BlownUpCapacitor]

If those other transistors on the sweep board test fine, check Q739 on the main board. Desolder it and put the scope into X-Y mode, then power it on. DO NOT CHANGE TO ANY OTHER FUNCTION OTHER THAN XY with this transistor removed.

If that doesn't rectify the issue, report back.

[BTO]

If those other transistors on the sweep board test fine, check Q739 on the main board. Desolder it and put the scope into X-Y mode, then power it on. DO NOT CHANGE TO ANY OTHER FUNCTION OTHER THAN XY with this transistor removed.

If that doesn't rectify the issue, report back.

OK, will do, Let me catchup on all the instructions thus far, I'll have a bit more time tomorrow, i'm a bit busy tonight.
but i am on top of this. so bear with me for like 24 hours,
its' more figuring out how to disassemble those damn 3 boards from each other.
but give me 24 hours and i will report back, speak to you soon,  thanks heaps for your ongoing help.

[BTO]

HANG ON.... HOLD THE PHONE
Ch1 Position knob DOES HAVE AN EFFECT

it would appear that if the position knob
As per Photo 27
if it's set all the way to the right THE CIRCLE IS SMALLER

As per Photo 28
if it's set all the way to the right THE CIRCLE IS BIGGER

but if the position knob does not affect the vertical movement in any way

Hmmm.  Try changing the positions of the vertical mode switches (ADD/CHOP/ALT and CH1/CH2/BOTH) to see if there is any change.  Also, disable the signal to CH1/X temporarily and verify that whatever fragment of circle you have is due to that signal.  I think you have a channel switching problem of some sort, although I'm not sure what.  Check the XY and (not)XY signal as I said before and then start looking at everything they control.  I can't see how the CH1 position control would have that effect (or any) unless CH1 is not getting fully disconnected from the vertical amplifier when commanded.  And since any such issues would cause big problems in other modes, this particular issue (but perhaps not all of them) is likely related to the control of U130 by the XY logic line through S550, U540 and related nearby parts.

I CONDUCTED A VERY THOROUGH TEST ON ALL THE BUTTONS AND KNOBS AND SWITCHES
The Results are as follows

For testing purposes i have set both SIG GEN Channels to
Sine Wave
1Hz
2V

===================================================
MAIN CONTROLS
===================================================

INTENSITY      - Works as Expected and Adjusted
TRACE ROTATION - Works as Expected and Adjusted
BEAM FIND      - Works as Expected
PROBE ADJUST   - Works as Expected
FOCUS          - Works as Expected and Adjusted
POWER          - Works as Expected and Powered ON

===================================================
VERTICAL CONTROLS
===================================================
============================================================================
NOTES :

CH1 Initially set to 1 Volt/Div
CH2 Initially set to 1 Volt/Div
Timebase set to 1ms/Div  (Freq 1kHz)

Trace position without any input is set to to the 0V Midline

Changed BOTH Sig Gen Channels to 1kHz for calibration of amplitude.
Calibrated with a Square wave of 2 V Peak to peak

Then Tested basic signal input of the following waves.
- Sine
- Square
- Triangle
- DC

Performed on Both Channels
Both Channels PASSED
============================================================================

-----------------------------
VERTICAL MODE CONTROLS
-----------------------------
Switch (CH1 / BOTH / CH2)
CH1  - Works as Expected
BOTH - Works as Expected
CH2  - Works as Expected
-----------------------------
Button (BW LIMIT 10MHz) - Works as Expected
Button (CH2 Invert)     - Works as Expected
-----------------------------
Switch (ADD / ALT / CHOP)
ADD  - Works as Expected
ALT  - Works as Expected
CHOP - Works as Expected
-----------------------------

-----------------------------
CHANNEL 1 CONTROLS
-----------------------------
CH1 POSITION KNOB  - Works as Expected

CH1 VOLTS/DIV DIAL - Works as Expected
Tested with 1V, 2V, 3V, 4V, 5V
Stops at each level at the correct level

CH1 CAL AJDUSTMENT - Works as Expected

SWITCH (AC GND DC)
AC  - Works as Expected
GND - Works as Expected
DC  - Works as Expected
-----------------------------

-----------------------------
CHANNEL 2 CONTROLS
-----------------------------
CH2 POSITION KNOB  - Works as Expected

CH2 VOLTS/DIV DIAL - Works as Expected
Tested with 1V, 2V, 3V, 4V, 5V

CH2 CAL AJDUSTMENT - Works as Expected

SWITCH (AC GND DC)
AC  - Works as Expected
GND - Works as Expected
DC  - Works as Expected
-----------------------------
===================================================
HORIZONTAL CONTROLS
===================================================
-----------------------------
HORIZONTAL MODE CONTROLS
-----------------------------
Switch (NO DLY / INTENS / DLY'D)
NO DLY - Works as Expected
INTENS - Works as Expected
DLY'D  - Works as Expected
-----------------------------
-----------------------------
HORIZONTAL CONTROL
-----------------------------
HORIZONTAL POSITION KNOB - Works as Expected
HORIZONTAL SEC/DIV DIAL  - Works as Expected
X10 CAL AJDUSTMENT (PULL AND ADJUST) - Works as Expected

DELAY TIME
SWITCH 0.4ms  20us  1.0us
0.4ms - Works as Expected
20us  - Works as Expected
1.0us - Works as Expected

Multiplier Knob
< x1  to  >x50
- Works as Expected
-----------------------------
===================================================
TRIGGER CONTROLS
===================================================
VAR HOLDOFF KNOB
Norm (Anti clockwise) to Max (Clockwise) - Works as Expected
BUTTON SGL SWP reset button - Works as Expected
BUTTON P.P AUTO - Works as Expected
BUTTON NORM - Blanks the Screen
BUTTON SLOPE - Works as Expected
LEVEL KNOB - Works as Expected

INT SWITCH
CH1       - Works as Expected
VERT MODE - Works as Expected
CH2       - Works as Expected

SOURCE SWITCH
INT  - Works as Expected
LINE - Works as Expected
EXT  - Works as Expected

EXT COUPLING SWITCH
AC
DC
DC / 10

DID NOT TEST, NOT RELEVANT
=====================================================


ENTERING XY MODE

SIG GEN 1
Sine Wave
1000Hz
2V

SIG GEN 2
Sine Wave
1001Hz
2V

Changed only Time Base to XY Mode

RESULT
- NO DISPLAY ON SCREEN
(Horizontal Position Adjustment needed)

- Horizontal Position Adjusted to the centre line
- Amplitude is correct
- However there is no immediate circle or Diagonal Line


TESTED ON ANOTHER SCOPE "Entering XY Mode" as above.
My Kikusui scope on the same settings IMMEDIATELY IN XY Mode
had the full circle in the centre without adjustment needed

when changed to YT Mode, Diagonal Line appeared.
that doesn't happen on this scope

From this position
- REMOVED CHANNEL 1 SIGNAL CABLE
no change - 2V Vertical signal remains

REPLACED Ch1 Cable
- REMOVED CHANNEL 2 SIGNAL CABLE
- 2V Vertical signal disappears and becomes a single dot

Those results occur regardless of whether the switch is in
CH1 , Both, Ch2 Mode

FROM HERE
Channel 2 Dial reacts and changes the amplitude accordingly

Channel 1 - I need to change from 1V/Div  to at least 100mV/Div
        Before i can see only a small semicircle

        If i change from 100mV/Div  to 50mV/Div the Semi Circle shoots out
        disproportionately to the voltage change.

at 100mV the semi circle extends out by 1/2 a Division
at 50mV the semi circle extends out beyond 5 divisions, specifically 9.5 divisions

None of this was required on my working Kikusui scope.

So it would appear
- The Main controls seem to work
- Ch 1 controls seem to work correctly
- Ch 2 controls seem to work correctly
- the scaling seems to work and be on par and correct
- Trigger controls seem to work
- The front end inputs seem to work
- the selector for Ch1 , 2 and Both seem to work perfectly

the problem only seems to occur when entering XY Mode
and when an input is removed, there is no Horizontal line
and there is an obvious offset of 5 divisions to the left

I APOLOGIZE FOR BEING A STRANGER AND DROPPING OFF THE PLANET
I have COVID and was sick as a dog. i'm significantly better now.
so i'll get stuck into it again.  I'll report back soon with the disassembly of the scope and trying to find the problem and checking out those
suspect components .

[BTO]

Quick Update,
After my COVID i got back into it, the problem i'm currently having is how to separate the 4 boards,
there's a Mainboard (Horizontally) then on top of that a stack of 2 other boards (horizotally),
and then a front panel board (Vertically).  Still can't work out how to separate these boards.
I'll keep trying.

[Miti]

TL;DR Did you try to select CH2 on CH1 BOTH CH2 switch? I remember having similar issues with my Tek 2445A.

[BlownUpCapacitor]

I don't think the channel mode switches interfere with the X-Y mode of operation if I remember from my Tek 2213.

[Miti]

I think it does.

Edit: I’ve attached a screenshot from a w2aew video on YouTube. Not the same model but something to consider.

And see here the reply from Chuck Harris
https://groups.io/g/TekScopes/topic/question_regarding_xy_mode/30854252?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,0,0,30854252

[BlownUpCapacitor]

That's for the 24xx. I'm talking about the 22xx. My 2230 isn't affected by the vert mode switch in X-Y.