Date
1 - 20 of 22
Tektronix 465
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Peter Margolis
I have a 465 that just lost half of it's trace. I was wondering if anyone here might help me work on repairing this scope?
thanks pete |
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Steph L
What part is lost and what isn't?
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Abc Xyz
Hello
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My recent aqusition of a 465B has a situation where Both Traces are too Short for the Screen. Many hours of Troubleshooting and I cant figure out why?! JR 951-551-3928 On Tue, May 7, 2019, 1:28 PM Steph L <stephlan@...> wrote:
What part is lost and what isn't? |
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Merchison Burke
Have you checked the power supplies as described in the manual?
On 2019-Jul-12 12:02 PM, Abc Xyz wrote: Hello --- This email has been checked for viruses by AVG. https://www.avg.com |
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Abc Xyz
Yes...the Power Supplies are Spot On with No Ripple.
On Fri, Jul 12, 2019, 10:14 AM Merchison Burke via Groups.Io <merchison= yahoo.co.uk@groups.io> wrote: Have you checked the power supplies as described in the manual? |
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Abc Xyz
Both Traces are about four Graticules Short of a Full Screen...the Position
Knob in Full CW or CCW Rotation does not Resolve the Issue. JR On Fri, Jul 12, 2019, 10:16 AM Abc Xyz via Groups.Io <yawrdanza= gmail.com@groups.io> wrote: Yes...the Power Supplies are Spot On with No Ripple. |
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Abc Xyz
They Both seem to be Lost on the Right Hand Side of the Screen.
On Fri, Jul 12, 2019, 10:22 AM Abc Xyz via Groups.Io <yawrdanza= gmail.com@groups.io> wrote: Both Traces are about four Graticules Short of a Full Screen...the Position |
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Abc Xyz
I have been through the Horizontal Section with a Fine Tooth Comb. I have
Tested all the Transistors and they are Good. Only a Couple if Capacitors and they dont appear to be Faulty. However, Voltages seem to be Out of Spec throughout. JR On Fri, Jul 12, 2019, 10:24 AM Abc Xyz via Groups.Io <yawrdanza= gmail.com@groups.io> wrote: They Both seem to be Lost on the Right Hand Side of the Screen. |
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Paul Amaranth
How did you test the transistors? I've had situations where a simple
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transistor checker said they were good but my curve tracer showed how they were bad. Paul On Fri, Jul 12, 2019 at 10:32:37AM -0700, Abc Xyz wrote:
I have been through the Horizontal Section with a Fine Tooth Comb. I have --
Paul Amaranth, GCIH | Manchester MI, USA Aurora Group of Michigan, LLC | Security, Systems & Software paul@... | Unix & Windows |
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Abc Xyz
I used one of those Digital Component Testers from China. And I used the
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Swap Method. I don't have a Curve Tracer so I suppose one or more could be Faulty. JR On Fri, Jul 12, 2019, 10:39 AM Paul Amaranth <paul@...> wrote:
How did you test the transistors? I've had situations where a simple |
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Harvey White
Does the beam finder switch have any effect?
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Some of the contacts may be stuck. Voltages may change under beam finder mode. Harvey On 7/12/2019 1:32 PM, Abc Xyz wrote:
I have been through the Horizontal Section with a Fine Tooth Comb. I have |
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Abc Xyz
The Beam Finder seems to Work Properly.
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951-551-3928 On Fri, Jul 12, 2019, 11:19 AM Harvey White <madyn@...> wrote:
Does the beam finder switch have any effect? |
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Paul Amaranth
Then you're going to have to do it the hard way and figure out why you're
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voltage readings are off. You may have a leaky transistor or faulty IC somewhere. With the position knob centered, are the traces equally short on each side or more on one side or the other? Paul On Fri, Jul 12, 2019 at 10:43:30AM -0700, Abc Xyz wrote:
I used one of those Digital Component Testers from China. And I used the --
Paul Amaranth, GCIH | Manchester MI, USA Aurora Group of Michigan, LLC | Security, Systems & Software paul@... | Unix & Windows |
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Abc Xyz
I changed one of the IC's...no change. The Traces seem Normal to the Left
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but Short 4 Graducles to the Right. On Fri, Jul 12, 2019, 12:03 PM Paul Amaranth <paul@...> wrote:
Then you're going to have to do it the hard way and figure out why you're |
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On Fri, Jul 12, 2019 at 09:08 PM, Abc Xyz wrote:
- What IC's did you change? AFAUIK, the horizontal output amplifier in the 465(B) contains no IC's. - Do you have a 465 or a 465B? You mention both. - Are you sure that both horizontal plates (underside of 'scope) are connected? Raymond |
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Abc Xyz
The Scope is a 465B. Even Textronix, and others, said there was no IC in
the Horizontal Section. The IC I Replaced was: U4269 (Schematic Location: 5D,2D,6G and 2G. Board Location: 5I, Component No: AU4269, Tektronix Part No: 256-0197-00, Serial No: B010100 B039319, Name & Description: Microcircuit, LI:5 Transistor Array, Mfr Code: 80009, Mfr Part No: 156-0197-00). I have Checked Both Connections to the CRT Horizontal Plates. JR 951-551-3928 On Fri, Jul 12, 2019, 12:18 PM Raymond Domp Frank <hewpatek@...> wrote: On Fri, Jul 12, 2019 at 09:08 PM, Abc Xyz wrote:- What IC's did you change? AFAUIK, the horizontal output amplifier in |
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On Fri, Jul 12, 2019 at 10:00 PM, Abc Xyz wrote:
You're right, that 5-transistor array *is* an IC. Raymond |
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Strange, U4269 is an unusual case; two numbers used, depends on s/n. 156-0197-00 (NSC LM3146N) only used on s/n B010100 through B039319 and 156-0048-03 (MOT SC77161P) used on B039320 and up. I have no idea if it would make a difference, but did you replace your part with the correct part for your serial number?
-- Michael Lynch Dardanelle, AR |
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Abc Xyz
Yes
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On Fri, Jul 12, 2019, 1:40 PM Mlynch001 <mlynch002@...> wrote:
Strange, U4269 is an unusual case; two numbers used, depends on s/n. |
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Harvey White
Then I guess we need to do it the hard way.
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Looking at the horizontal plates, short them together temporarily. Whatever you get ought to be centered horizontally (more or less) and vertical we don't know about. That tends to verify the CRT. Secondly: center the horizontal positioning. Use a spot (DC H input) with the intensity down so you don't damage the screen. Put the centering control to mid position. Check the voltage excursion from full left to full right, and then check the voltage when centered. The difference between the plates when full left and full right should be rather close. If one output (for instance, the one for the right plate) is limited in range, then your problem is in that half. For this test, I'd turn the intensity down completely. Center the centering control, do X input, and make it a zero. If everything is correct, then the spot ought to be centered once you turn the intensity up. look for balance between the channels as you go from the input to the output. If you have a properly centered spot, and still the trace can't go far right, then the fault is that the right plate driver doesn't have enough voltage excursion. The fault is likely after the centering pot. (note: check the voltages to the stage before the centering pot, it ought to be the same on both + and - drivers. If you can't get a properly centered spot with the centering control, then that suggests that the circuitry before the centering control is out of balance. With the input grounded (a good idea), somewhere, someplace, something is out of balance if the problem is that the spot is not centered. If on the other hand, up to the centering control everything is balanced, then past that, something is either not balanced, or something doesn't have enough of an excursion (running output voltage range) to make the circuit work. Harvey On 7/12/2019 4:07 PM, Raymond Domp Frank wrote:
On Fri, Jul 12, 2019 at 10:00 PM, Abc Xyz wrote:Even Textronix, and others, said there was no IC inYou're right, that 5-transistor array *is* an IC. |
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