Oscilloscope UNAOHM G4020 = BECKMAN 9020

Collapse
X
 
  • Time
  • Show
Clear All
new posts

  • eccerr0r
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Show a photo of the insides to us, I picked out one wire from the schematic, perhaps we can find that wire in a picture for you to inspect, at least visually, if you don't have another scope to check it.

    But wait, you say vertical amplifier is OK, so if you feed in an AC to the vertical inputs, you should be able to see a vertical line, perhaps requiring the use of the beamfinder button. If you're not getting any vertical line with an AC input, then we have some strange dual failure that my be just a switch problem.
    Last edited by eccerr0r; 08-02-2018, 07:45 PM.

    Leave a comment:


  • neuron
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by eccerr0r
    This is where the second scope would be good. Because we are getting sweep output from the back (but how good of a ramp output is it? Aha..need another scope.) the sweep generator is working as far as I can tell. This output is directly used for the X deflection through R6001 and R961.

    But you say you can move the X dot from left to right with the X pos potentiometer, so the X amplifier is working depending on T908. But one can't work without the other.

    Some observation is conflicting here. Well, unless if one of R6006 or R961 is broken, HG1 connector is broken, or the wire broke...
    Thank you very much for your detail research.

    BEAM FINDER ok

    And the Y ... I can't see any vertical lines, only one dot.
    Vertical Final Amplifier is ok

    Any control before this blocks?


    " ... have you looked inside yet? ..."
    search for any ...


    Regards,

    Ruy

    Leave a comment:


  • eccerr0r
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    This is where the second scope would be good. Because we are getting sweep output from the back (but how good of a ramp output is it? Aha..need another scope.) the sweep generator is working as far as I can tell. This output is directly used for the X deflection through R6001 and R961.

    But you say you can move the X dot from left to right with the X pos potentiometer, so the X amplifier is working depending on T908. But one can't work without the other.

    Some observation is conflicting here. Well, unless if one of R6006 or R961 is broken, HG1 connector is broken, or the wire broke...
    Last edited by eccerr0r; 08-02-2018, 11:10 AM.

    Leave a comment:


  • stj
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    have you looked inside yet?

    Leave a comment:


  • neuron
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by stj
    does the x-pos control in the upper right efect the dot position?
    and make sure "single" isnt pushed.
    Let me rephrase ... explain ...

    If the Scope is working properly and you select XY or
    Test Comp = Curve Trace you get a dot in middle of screen or
    in CT a single line ... because no component in the leads.
    only volts.

    In this case I don't get nothing in the screen. :-(
    Because the dots are hid. in left side - border.

    Everything in middle position (X-POS, Y-POS) or
    off (HOLD-OFF ->MIN, VAR-CAL off, etc)
    DELAY -> N
    Push Buttons -> not press ... none

    Lets begin.

    Nothing in the screen ...

    Rot. the X-POS (white mark in middle ) the dot emerge
    from the left side.
    And I can move anywhere in the screen.


    Originally posted by redwire
    It might be in component test mode. Check the C.T. button is not in.
    Read my last posts.




    I would like to clean the Knobs, Handles, Pulls and Switches what you suggest? Alc. Isop.?



    The Youtuber - Bruce Parman - bap8guy - usual. in the Forum ?

    He repair this units.

    https://www.youtube.com/channel/UCYi...vwudcjPwj80N-Q

    https://plus.google.com/108120951169835381639

    Regards,
    Ruy

    Leave a comment:


  • redwire
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    It might be in component test mode. Check the C.T. button is not in.

    Leave a comment:


  • stj
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    does the x-pos control in the upper right efect the dot position?
    and make sure "single" isnt pushed.

    Leave a comment:


  • neuron
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by eccerr0r
    Might be best if you post pictures of the exact screen (and controls) of your device, it's hard to tell what you see by text. A good cleaning of the time/div switch is good just to make sure.

    Since you can move the dots up and down, vertical deflection is working.

    So you do see some horizontal deflection of the beam even if it's not fully across the screen?

    Yes having another scope is good because then you can use one to debug the other. I don't think 4 1ch scopes are necessarily good, but having two 2-channel scopes is better than having one 4-channel, the dual trace scopes are helpful unless your only 2-channel scope is dead...
    Yes

    Some pics ... feeling of device


    "if it is not triggering you should not see a static dot.
    as it's been around a bit, first idea is to open it and check for loose connectors. "

    Ok I will test.

    Regards,
    Ruy
    Attached Files
    Last edited by Per Hansson; 08-02-2018, 05:09 AM. Reason: Rotated pictures

    Leave a comment:


  • stj
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    if it is not triggering you should not see a static dot.

    as it's been around a bit, first idea is to open it and check for loose connectors.

    Leave a comment:


  • eccerr0r
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Might be best if you post pictures of the exact screen (and controls) of your device, it's hard to tell what you see by text. A good cleaning of the time/div switch is good just to make sure.

    Since you can move the dots up and down, vertical deflection is working.

    So you do see some horizontal deflection of the beam even if it's not fully across the screen?

    Yes having another scope is good because then you can use one to debug the other. I don't think 4 1ch scopes are necessarily good, but having two 2-channel scopes is better than having one 4-channel, the dual trace scopes are helpful unless your only 2-channel scope is dead...

    Leave a comment:


  • neuron
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by eccerr0r
    Do you have another oscilloscope? (All debug technicians should always own at least TWO oscilloscopes, better two 1-channel oscilloscopes than one 2-channel unit!)

    If you can move the dots from left to right, then the horizontal output amps are working. As you get the proper ramp sweep output on the back, the problem is in the sweep/timebase oscillator output switch/mux reaching horizontal deflection. (Then again I have not looked at your scope's schematic yet.)

    It still could mean trigger is not working.

    Not a usual failure if it's not being caused by front panel selections...
    Thank you very much for your info.

    1 - At moment no ... but in a few days ... I have one.
    Sorry don't understand ... its better 4 Scopes 1 CH ... instead a Scope with 4 CH?

    2 -" ... I can move the dots UP and DOWN ... "

    Vertical output amps work?

    " ... As you get the proper ramp sweep output on the back ... "
    I don't know if the waveform is ok ...
    I rotate TIME / DIV, and the DMM -
    300 Hz -> KHz

    3 - "... It still could mean trigger is not working ..."

    I explained in previous post:

    I test the trigger, connected CAL 0,2 V to ch 1 or 2
    and the dot go UP ( DOWN ) 1 , 2 or more lines up ( down) depend on VOLT/DIV

    INV - and the dot go down invert many lines depend on VOLT / DIV.

    A sinos. wave - I move TRIG LEVEL and the dot trigger the sin wave, moving slowly up or down the dot as I rotate the TIG LEVEL.


    4 - "...front panel selections ... "
    I would like to clean the Knobs, Handles, Pulls and Switches what you suggest? Alc. Isop.?


    If TIME / DIV is 5, 10 us I saw the dot and a trace ( tail ) with 1 cm.

    Regards,
    Ruy

    Leave a comment:


  • eccerr0r
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by stj
    i have 4.
    including a 4 channel DSO, a 50MHz handheld and a 100MHz 3channel one that can show 6 traces!!
    well I wouldn't expect any less from you! but the OP.... needs more than 1!

    Leave a comment:


  • stj
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by eccerr0r
    Do you have another oscilloscope? (All debug technicians should always own at least TWO oscilloscopes, better two 1-channel oscilloscopes than one 2-channel unit!)
    i have 4.
    including a 4 channel DSO, a 50MHz handheld and a 100MHz 3channel one that can show 6 traces!!

    Leave a comment:


  • eccerr0r
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Do you have another oscilloscope? (All debug technicians should always own at least TWO oscilloscopes, better two 1-channel oscilloscopes than one 2-channel unit!)

    If you can move the dots from left to right, then the horizontal output amps are working. As you get the proper ramp sweep output on the back, the problem is in the sweep/timebase oscillator output switch/mux reaching horizontal deflection. (Then again I have not looked at your scope's schematic yet.)

    It still could mean trigger is not working.

    Not a usual failure if it's not being caused by front panel selections...
    Last edited by eccerr0r; 07-31-2018, 07:58 PM.

    Leave a comment:


  • neuron
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Originally posted by eccerr0r
    So you're saying your horizontal sweep/horizontal amplifier/time per division switch isn't working?

    Did you set it to perhaps XY mode by mistake? This thing appears to have a sort of curve tracer built in, so I suspect it can also do XY but I don't have a good picture of the front panel for sure. If you have a high frequency sine wave you should get a line?
    Thank you for your help.

    If I select XY mode the dots disappear.

    and if I press Comp. Test ( curve tracer ) the dots vanish
    This worked in first hours and I tested caps, trans. resist,


    Beam Find work 1 or 2 dots in midle of screen.

    In back, I can find a BNC with sawtooth ... and changing TIME / DIV, I tested with a DMM -
    300 Hz -> KHz


    I visualiz. the dots -> rotating the POS and the dots appear from left side.


    Thank you,

    Ruy
    Last edited by neuron; 07-31-2018, 06:54 PM.

    Leave a comment:


  • stj
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    make sure it's not in X-Y mode and the timebase is o.k.

    Leave a comment:


  • eccerr0r
    replied
    Re: Oscilloscope UNAOHM G4020 = BECKMAN 9020

    So you're saying your horizontal sweep/horizontal amplifier/time per division switch isn't working?

    Did you set it to perhaps XY mode by mistake? This thing appears to have a sort of curve tracer built in, so I suspect it can also do XY but I don't have a good picture of the front panel for sure. If you have a high frequency sine wave you should get a line?

    Leave a comment:


  • neuron
    started a topic Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Oscilloscope UNAOHM G4020 = BECKMAN 9020

    Hi,
    A friend offered
    Oscilloscope UNAOHM G4020 = BECKMAN 9020

    In first hours worked ok ... I saw the 0,2 V 1000Hz
    and other signal in the cinescop.

    But now I only see 1 or 2 dots (channel 1 or both or ch 2)

    I can move the dots UP and DOWN, LEFT and RIGHT
    so the screen - cinesc. is working.


    I test the trigger, connect CAL 0,2 to ch 1 or 2
    and the dot is in 1 , 2 or more lines up depend on VOLT/DIV
    INV - and the dot go down invert.

    A sinos. wave, I can rotate TRIG LEVEL and the dot follow
    the wave.
    But I can't see the wave in display

    Some examples of scope:
    https://www.youtube.com/watch?v=3nBYp1pN40U

    https://www.youtube.com/watch?v=fPq1KgQ5ggQ

    https://www.youtube.com/watch?v=5osskamWJHg

    Attach - manual and schemat. I have the French version.

    Can you please provide help?

    Thank you,

    Ruy
    Attached Files

Related Topics

Collapse

  • Document Archive
    HP Pavilion Wave Pavilion Wave Desktop - 600-a030na Pavilion Wave i3-6100T Specification for Upgrade or Repair
    by Document Archive
    This specification for the HP Pavilion Wave Pavilion Wave Desktop - 600-a030na can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Pavilion Wave Pavilion Wave Desktop - 600-a030na boardview and Pavilion Wave Pavilion Wave Desktop - 600-a030na schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps...
    09-12-2024, 03:44 PM
  • Document Archive
    HP Pavilion Wave Pavilion Wave Desktop - 600-a103na Pavilion Wave i3-7100T Specification for Upgrade or Repair
    by Document Archive
    This specification for the HP Pavilion Wave Pavilion Wave Desktop - 600-a103na can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Pavilion Wave Pavilion Wave Desktop - 600-a103na boardview and Pavilion Wave Pavilion Wave Desktop - 600-a103na schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps...
    09-12-2024, 02:00 PM
  • Document Archive
    HP Pavilion Wave 600-a055cn Pavilion Wave i5-6500T Specification for Upgrade or Repair
    by Document Archive
    This specification for the HP Pavilion Wave 600-a055cn can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Pavilion Wave 600-a055cn boardview and Pavilion Wave 600-a055cn schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification,...
    09-12-2024, 03:44 PM
  • Document Archive
    HP Pavilion Wave 600-a102ng Pavilion Wave i3-7100T Specification for Upgrade or Repair
    by Document Archive
    This specification for the HP Pavilion Wave 600-a102ng can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Pavilion Wave 600-a102ng boardview and Pavilion Wave 600-a102ng schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification,...
    09-12-2024, 02:00 PM
  • Document Archive
    HP Pavilion Pavilion Wave Desktop - 600-a059na Pavilion i5-6400T Specification for Upgrade or Repair
    by Document Archive
    This specification for the HP Pavilion Pavilion Wave Desktop - 600-a059na can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Pavilion Pavilion Wave Desktop - 600-a059na boardview and Pavilion Pavilion Wave Desktop - 600-a059na schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please...
    09-12-2024, 03:44 PM
  • Loading...
  • No more items.
Working...