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Thread: HP 54600A Display Image Squished


Permlink Replies: 19 - Pages: 2 [ 1 2 | Next ] - Last Post: Jan 5, 2014 10:23 AM Last Post By: bdtorr
Fixion

Posts: 3
Registered: 11/11/08
HP 54600A Display Image Squished
Posted: Nov 11, 2008 4:50 PM
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Attachment IMAGE_058.jpg (36.1 KB)
I have an HP 54600A oscilloscope that is having some problems with the display. The vertical axis of the screen seems to be squished and slightly distorted. The image is about half as tall as it should be, and slightly stretched on top. I've disassembled the scope and adjusted the "V. Size" and "V. Lin" POTs, and they help a little, but they don't have nearly enough range. Does anyone have a schematic of this oscilloscope? Does anyone have any idea as to what could be causing this problem?

I've attached an image of the screen, I apologize for the poor image quality, I didn't have a real digicam around, so I took the picture with my phone.
ko2054

Posts: 76
Registered: 06/06/07
HP 54600A Display Image Squished
Posted: Nov 12, 2008 12:17 PM   in response to: Fixion in response to: Fixion
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Hello Fixion,

It looks like you are loosing high voltage. We purchased the display from a third party vendor. I have a copy of their schematic that you can use. Agilent does not stock any replacement parts. Sorry. We replaced the display as a complete module. Maybe the attached schematic will help you out. The schematics for the 54600A are at the below web site.
http://www.home.agilent.com/agilent/edi ... id=1517718
Another copy of the display schematic is there also.
Let me know if you have more questions.
KO2054
DL1ZP

Posts: 7
Registered: 10/03/08
HP 54600A Display Image Squished
Posted: Nov 13, 2008 12:02 PM   in response to: Fixion in response to: Fixion
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Hello,

I had that problem too with my 54601 some time ago. Turned out that it was a dried out electrolytic capacitor in the vertical stage. It was marked C609 on the board in my case a 1000µF/16V. In the schematic it is C651.

Regards, dl1zp
Fixion

Posts: 3
Registered: 11/11/08
HP 54600A Display Image Squished
Posted: Dec 7, 2008 11:30 PM   in response to: Fixion in response to: Fixion
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Thank you very much for both the schematic and the advice! I'll try to replace the capacitor this week and post the results.
Fixion

Posts: 3
Registered: 11/11/08
HP 54600A Display Image Squished
Posted: Dec 12, 2008 6:12 PM   in response to: Fixion in response to: Fixion
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"
Hello,

I had that problem too with my 54601 some time ago. Turned out that it was a dried out electrolytic capacitor in the vertical stage. It was marked C609 on the board in my case a 1000µF/16V. In the schematic it is C651.

Regards, dl1zp
"


I found it! On my scope it was the electrolytic capacitor marked C608 on the board and C624 in the schematic with a value of 10µF/16V. I replaced it and the image is now full size!

Thanks for the help guys!
tonykara

Posts: 37
Registered: 02/23/08
HP 54600A Display Image Squished
Posted: Dec 18, 2008 10:52 PM   in response to: Fixion in response to: Fixion
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Congratulations!!!
tonykara

Posts: 37
Registered: 02/23/08
HP 54600A Display Image Squished
Posted: Dec 18, 2008 11:01 PM   in response to: Fixion in response to: Fixion
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Congratulations!!!
Stanish

Posts: 1
Registered: 04/19/09
Re: HP 54600A Display Image Squished
Posted: Apr 19, 2009 6:16 AM   in response to: Fixion in response to: Fixion
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Hello all,

I've similar problem with my HP 54601A. All the capacitors seems to be ok. Unfortunately, the display module doesn't match with the schematics. (546XXA_CLIP_Package.zip)
In my case it's a bit newer model:
CDM-7SF191, January 1991, Hitachi Mizusawa
there is used IC uPC1379C (NEC) and P030RV1 ? (Sharp)

The vertical deflection saw signal is distorded - saw sustain isn't linear, but parabolic.
I'll try to replace IC uPC1379C. Anyway, would be nice to have schematic to CDM-7SF191.

Hitachi support suggested to contact Agilent regarding schematic :(
Any suggestion aprecited...

Stanish
tonykara

Posts: 37
Registered: 02/23/08
Re: HP 54600A Display Image Squished
Posted: Apr 23, 2009 4:55 PM   in response to: Fixion in response to: Fixion
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At this point it could be handed to a TV repair guy who has better knowledge with these kind of circuits. He could probably fix it without too much trouble.
Silverman

Posts: 1
Registered: 08/05/09
Re: HP 54600A Display Image Squished
Posted: Aug 5, 2009 11:40 AM   in response to: Fixion in response to: Fixion
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I have a 1991 HP 54600A. It had the same problem (see http://www.flickr.com/photos/31143498@N03/3767146519/). I tried replacing C651 (C609) and (C653) to no effect. But replacing C608 (C624 on the schematic, 10µF 16V) fixed my problem right away, see http://www.flickr.com/photos/31143498@N03/3791913331/. I couldn't have done it without the guidance and schematic I found here. Thanks!
swohler

Posts: 2
Registered: 02/15/10
Re: HP 54600A Display Image Squished
Posted: Feb 15, 2010 7:38 AM   in response to: Fixion in response to: Fixion
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As it turns out, I am having the exact same issue. So before I jump in and change the cap, I'm just curious if anyone discharged the CRT prior to changing it, or is it far enough away from HV circuits that it wasn't an issue? Any recommendations?

Thanks,
Scott
swohler

Posts: 2
Registered: 02/15/10
Re: HP 54600A Display Image Squished
Posted: Feb 15, 2010 8:34 AM   in response to: Fixion in response to: Fixion
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Just wanted everyone to know that I changed the same cap in question, C608, and the problem is solved. Thanks so much for the insight!

-Scott
Stantym

Posts: 1
Registered: 05/28/10
Re: HP 54600A Display Image Squished
Posted: May 28, 2010 12:51 PM   in response to: Fixion in response to: Fixion
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I had the same problem with vertical deflection - replaced C608 and C609 and that cured the problem.

Many thanks for posting this fix on this board.

When I have more time I will replace all electrolytics on this Hitachi board - all of them must be dry.
pierre-yves

Posts: 1
Registered: 06/25/10
Re: HP 54600A Display Image Squished
Posted: Jun 25, 2010 6:17 PM   in response to: Fixion in response to: Fixion
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Same problem with my HP 54600A -> same solution.
Replaced C608 / C609. Image is full sized again.
Thanks a lot !

Pierre-Yves Andri (Belgium)
guanglier

Posts: 1
Registered: 08/05/10
Re: HP 54600A Display Image Squished
Posted: Aug 5, 2010 6:22 AM   in response to: Fixion in response to: Fixion
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Hey guys,

i got the same problem, and same solution (Replaced C608 / C609. Image is full sized again.)

thank you so much for all of these informations !

Cyrile ( France )

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