Date   

Re: Have a 2467B. Suggestions please on very poor focus

Mark Vincent
 

Raymond,

Thanks for letting me know the status of is scope. I did not know he had a video. I also am not on either of the other two groups. I only went by what was posted here. I do not know his level of experience or ones around him to help in person. Checking parts to confirm one way or another is one thing provided you know how and what to do. Changing is another.

Mark


Re: Have a 2467B. Suggestions please on very poor focus

 

On Tue, Jul 6, 2021 at 09:52 PM, Raymond Domp Frank wrote:


Siggi,
I already complained about Ronan's cross-posting. His main thread is on
TekScopes-2.
Here's the link to the video:
That quote doesn't work, of course.
This should:

https://groups.io/g/TekScopes2/files/Ronan_2476B_display_demo/20210706_090713.mp4

Raymond


Re: Have a 2467B. Suggestions please on very poor focus

 

On Tue, Jul 6, 2021 at 09:41 PM, Siggi wrote:


On Tue, Jul 6, 2021 at 3:25 PM Raymond Domp Frank <hewpatek@gmail.com>
wrote:


Ronan's 'scope works fine, generally, as can be seen in his video. Except
for the Rifa caps, replacement of components isn't "compulsory" and even
risky if one doesn't have the experience and tools needed to do quality
work.
I'd love to see that video, if only for reference to my 2467.
Siggi,
I already complained about Ronan's cross-posting. His main thread is on TekScopes-2.
Here's the link to the video:

**** QUOTE ****
The following files have been uploaded to the Files area of the TekScopes2@groups.io group.

/Ronan_2476B_display_demo/20210706_090713.mp4

By: Ronan <bass.woofer@gmail.com>

Description:
Demo of issue Ronan / 2476B with the finest focus I can get, while increasing the Readout Intensity from min to Max, the indicator LEDs flash as they do when I press "A/B Trig"
*** UNQUOTE ***

Raymond


Re: Have a 2467B. Suggestions please on very poor focus

Siggi
 

On Tue, Jul 6, 2021 at 3:25 PM Raymond Domp Frank <hewpatek@gmail.com>
wrote:

Ronan's 'scope works fine, generally, as can be seen in his video. Except
for the Rifa caps, replacement of components isn't "compulsory" and even
risky if one doesn't have the experience and tools needed to do quality
work.
I'd love to see that video, if only for reference to my 2467.


Re: Have a 2467B. Suggestions please on very poor focus

 

Ronan,
We're seeing the principal reason for my dislike of cross-posting.
You're getting responses from people who are unaware of what has been achieved and established already.
I fell into the same trap by responding on TekScopes after my responses on TekScopes-2.

Raymond


Re: Have a 2467B. Suggestions please on very poor focus

 

On Tue, Jul 6, 2021 at 09:17 PM, Mark Vincent wrote:


Ronan,

Check the power supply voltages for d-c and ripple. The electrolytics, some
resistors and several tantalums are known to give problems. Mr. Yachad of
Condor Audio has a parts kit for the 2465/7 series with instructions. He will
be glad to help you if you have questions. He is on this group. He is
excellent with these series of scopes.

You can check pin 2 of U4310 to see if you have the -2kv. The heater supply
can be checked at pins 1 and 14 of U4310 using a battery operated meter or
VOM, e.g. Simpson 260, across the two pins to see if you have the 6,3VAC for
the heater. Do NOT measure the heater voltage from ground to either pin 1 or
14! Pin 3 of U4310 should be about -2100V, Check TP4302 for -1100V, If these
voltages are low, the power supply is suspect as it is common to both
oscillator circuits. Replacing the parts in the power supply and elsewhere can
make things work right that look bad before replacing. Your focus and dim
trace likely will be right with the new parts. U4310 can be bad. The focus
adjust should be from 0 to 15V on one side of R4435. Check the zeners, diodes
and transistors in the focus circuit to confirm if any are bad. R4333 I will
say is way out of tolerance. Mouser has radial types in 100meg. The 1/2W or 1W
will work fine. The original carbon one could be 50, 60, etc. percent high or
even open. The carbon one in my 2465B was 170meg. It was replaced with a new
one. Here is the link for 1W types in stock:
https://www.mouser.com/Passive-Components/Resistors/Film-Resistors/Thick-Film-Resistors-Through-Hole/_/N-7gz43Z1yzvvqx?P=1z0vkovZ1z0wsz3Z1z0wljo&Keyword=100+meg+resistor&FS=True.
The 1/2W part number is: 588-MOX-300001006FE. The 1/2W is more expensive than
the 1W.

The 2 100mfd decoupling electrolytics for the two oscillator circuits should
be replaced with something like Nichicon ULD or UHE type. The kit mentioned
above likely has these two in it. Mr. Y. can confirm this.

The RIFA caps are to be pulled out and replaced! Those I know are in the kit.
Anyone on this group will attest to replacing these automatically/on-sight.

I hope you get this nice scope working right. It is a great scope.

Mark
Hi Mark,
Ronan's 'scope works fine, generally, as can be seen in his video. Except for the Rifa caps, replacement of components isn't "compulsory" and even risky if one doesn't have the experience and tools needed to do quality work.

Raymond


Re: Have a 2467B. Suggestions please on very poor focus

Mark Vincent
 

Ronan,

Check the power supply voltages for d-c and ripple. The electrolytics, some resistors and several tantalums are known to give problems. Mr. Yachad of Condor Audio has a parts kit for the 2465/7 series with instructions. He will be glad to help you if you have questions. He is on this group. He is excellent with these series of scopes.

You can check pin 2 of U4310 to see if you have the -2kv. The heater supply can be checked at pins 1 and 14 of U4310 using a battery operated meter or VOM, e.g. Simpson 260, across the two pins to see if you have the 6,3VAC for the heater. Do NOT measure the heater voltage from ground to either pin 1 or 14! Pin 3 of U4310 should be about -2100V, Check TP4302 for -1100V, If these voltages are low, the power supply is suspect as it is common to both oscillator circuits. Replacing the parts in the power supply and elsewhere can make things work right that look bad before replacing. Your focus and dim trace likely will be right with the new parts. U4310 can be bad. The focus adjust should be from 0 to 15V on one side of R4435. Check the zeners, diodes and transistors in the focus circuit to confirm if any are bad. R4333 I will say is way out of tolerance. Mouser has radial types in 100meg. The 1/2W or 1W will work fine. The original carbon one could be 50, 60, etc. percent high or even open. The carbon one in my 2465B was 170meg. It was replaced with a new one. Here is the link for 1W types in stock: https://www.mouser.com/Passive-Components/Resistors/Film-Resistors/Thick-Film-Resistors-Through-Hole/_/N-7gz43Z1yzvvqx?P=1z0vkovZ1z0wsz3Z1z0wljo&Keyword=100+meg+resistor&FS=True. The 1/2W part number is: 588-MOX-300001006FE. The 1/2W is more expensive than the 1W.

The 2 100mfd decoupling electrolytics for the two oscillator circuits should be replaced with something like Nichicon ULD or UHE type. The kit mentioned above likely has these two in it. Mr. Y. can confirm this.

The RIFA caps are to be pulled out and replaced! Those I know are in the kit. Anyone on this group will attest to replacing these automatically/on-sight.

I hope you get this nice scope working right. It is a great scope.

Mark


Re: My 475

 

Rey,

When you say that "the screen lites up" what do you mean by that? Are you saying that you have two straight lines, but when you apply a signal to either input channel you don't get any vertical deflection of either trace?

As other's have said, the first step in any diagnosis like this is to check the power supply voltages. This is easy to do on the 475 as there are labeled test points on the main interface board for each power supply rail.

I will hold my own speculation about what the fault might be until after we find out what the power supply voltages are.

-- Jeff Dutky


Re: My 475

Tom Lee
 

Dagnabit -- you're right, Dave.  I'm apparently thinking of a chart in some manual for another model.

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 7/6/2021 10:52, Dave Peterson via groups.io wrote:
Just scanned the 475 SM online doc. I didn't find a diagnosis chart - is that not in the online 475 manual?

Wanted to throw this in the suggestion box - after checking and verifying the LV supplies: check F1318 at the rear of the main board - near the transformer. This drives the HV oscillator and the tantalum 47uF cap on the other side of the fuse is a somewhat common short. It's a relatively easy fix. Don't bypass the fuse if it's out, check for a shorted C1318. That'll take down the CRT without affecting the LV supplies and other indicators.

Dave



On Tuesday, July 6, 2021, 9:47:36 AM PDT, Rey via groups.io <cis181ellin=yahoo.com@groups.io> wrote:
Hi guys, my first post here looking for answer I found this place. I'm looking for a bit of guidance, my 475 just quit it was working fine. Both channels are gone, no beam find. Every switch light works, the screen lites up. But no trace out of either channel.  I'm a hobbiest and I understand that electrical things do weird things.  But any ideas and/or pointers would be appreciated. I already downloaded the schematic.
Thanks









Re: My 475

Dave Peterson
 

Just scanned the 475 SM online doc. I didn't find a diagnosis chart - is that not in the online 475 manual?

Wanted to throw this in the suggestion box - after checking and verifying the LV supplies: check F1318 at the rear of the main board - near the transformer. This drives the HV oscillator and the tantalum 47uF cap on the other side of the fuse is a somewhat common short. It's a relatively easy fix. Don't bypass the fuse if it's out, check for a shorted C1318. That'll take down the CRT without affecting the LV supplies and other indicators.

Dave

On Tuesday, July 6, 2021, 9:47:36 AM PDT, Rey via groups.io <cis181ellin=yahoo.com@groups.io> wrote:

Hi guys, my first post here looking for answer I found this place. I'm looking for a bit of guidance, my 475 just quit it was working fine. Both channels are gone, no beam find. Every switch light works, the screen lites up. But no trace out of either channel.  I'm a hobbiest and I understand that electrical things do weird things.  But any ideas and/or pointers would be appreciated. I already downloaded the schematic.
Thanks


Re: My 475

Tom Lee
 

Welcome!

Standard procedure is to check the supplies (there are several in that scope). A quite common problem is a shorted "teardrop" tantalum capacitor, but a few quick measurements will tell you a lot.

If you've downloaded the manual, you should also take a look at the troubleshooting chart. The manual is incredibly well written.

Good luck!

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 7/5/2021 18:48, Rey via groups.io wrote:
Hi guys, my first post here looking for answer I found this place. I'm looking for a bit of guidance, my 475 just quit it was working fine. Both channels are gone, no beam find. Every switch light works, the screen lites up. But no trace out of either channel. I'm a hobbiest and I understand that electrical things do weird things. But any ideas and/or pointers would be appreciated. I already downloaded the schematic.
Thanks




Re: My 475

Paul Amaranth
 

Check all of the LV power supplies. That's always the first stop. Get the
service manual and make sure all of the supplies are within spec for voltage
AND ripple. Nothing works if the power supplies aren't right.

Paul

On Mon, Jul 05, 2021 at 06:48:42PM -0700, Rey via groups.io wrote:
Hi guys, my first post here looking for answer I found this place. I'm looking for a bit of guidance, my 475 just quit it was working fine. Both channels are gone, no beam find. Every switch light works, the screen lites up. But no trace out of either channel. I'm a hobbiest and I understand that electrical things do weird things. But any ideas and/or pointers would be appreciated. I already downloaded the schematic.
Thanks







!DSPAM:60e48921145828472026532!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@AuroraGrp.Com | Unix/Linux - We don't do windows


Re: My 475

 

My inbuilt autoresponder says: "Check the low voltages" and report back. The voltages are interdependent.
Highly likely you'll find a defective/shorted (Tantalum) capacitor.
Use dwg11 in the service manual as a reference.

Raymond


Have a 2467B. Suggestions please on very poor focus

Ronan
 

[Cross-posted to TekScopes2 and Tektronix]

Greetings!

I've acquired a 2467B, with no power-up error codes, but very poor focus. It has SN of BO50000+.

It's been in storage some years. I let it sit / powered on a couple days, same issue (as I expected). In the 2465B/2467B service manual, Preliminary Troubleshooting flowchart, I get past the 4'th step just prior to the PS test step, and now I have a decision to make.

Any experience with availability / sources of the CRT 154-0850-01 is appreciated -- having had some past experience with CRTs, and lack of diagnostics errors prior to the PS checks, time it has been in storage -- this "feels" like a soft/weak CRT. The traces don't appear to be distorted (rather are basically barely readable, totally out of focus).

As I assumed, I find no new / NOS tubes, I do see one seller on eBay/Greece -- they seem to go for between 75 and 300$ US. So, can be expensive.

As well, any ideas on the going price for a used 2467B such as this (unusable until the focus is fixed), is appreciated!

Opts 5H and 09.

There are no major cosmetic flaws, but the intensity control outer shell has fallen off.

Thank you !

Ronan
N. Cal.


My 475

Rey
 

Hi guys, my first post here looking for answer I found this place. I'm looking for a bit of guidance, my 475 just quit it was working fine. Both channels are gone, no beam find. Every switch light works, the screen lites up. But no trace out of either channel. I'm a hobbiest and I understand that electrical things do weird things. But any ideas and/or pointers would be appreciated. I already downloaded the schematic.
Thanks


Dennis Tillman

 

[I erroneously posted this message on the TekScopes-2 group first.
Sorry about that!]

A few days ago, I sent a PM to Dennis, because I hadn't seen a message from him for a while.
So far, no response.
Does anyone know whether his area is perhaps still off-line because of the heatwave?

Raymond


Re: Trouble shoot and extremely stubborn 465B

 

On Tue, Jul 6, 2021 at 06:07 AM, <Zentronics42@gmail.com> wrote:


*SOLVED* seems the tech before me that was in this unit flipped 2 of the micro
coax lines. J1101 and J1002 were flipped on the vertical board side. Seems
everything was testing good because it was. I was chasing an elephant with a
microscope.
Congratulations!

I hope my two suggestions
"Don't ignore the possibility of someone having made an assembly error"
and
"I'd check the trigger inputs to the trigger logic board (dwg6 area A1 -A2). You may check and disconnect Ch1 and Ch2 trigger input cables there. Even swap if no result"
saved you some time.
Been there, done that...

Raymond


Re: Members in Australia

 

John

Slightly OT
I need some help to source some spare parts in Oz, from Wagner and another supplier.

If any Oz members are willing to help , please reply to me - yachadm AT gmail DOT com

Thanks

Menahem
CondorAudio


Re: Members in Australia

Tom Gardner
 

If you aren't already aware of it, can I note that there are many such people on the EEVBlog Forum.
It has active sub-forums for test equipment and for equipment wanted and for sale.
https://www.eevblog.com/forum/index.php
https://www.eevblog.com/forum/testgear/
https://www.eevblog.com/forum/buysellwanted/

On 06/07/21 03:51, penguin2004au wrote:
Greetings all:
Just curious to see how many members are Down Under, if only because I might
have to downsize my collection soon.
Regards: John.


Re: Trouble shoot and extremely stubborn 465B

Zentronics42@...
 

*SOLVED* seems the tech before me that was in this unit flipped 2 of the micro coax lines. J1101 and J1002 were flipped on the vertical board side. Seems everything was testing good because it was. I was chasing an elephant with a microscope.

Zen

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Zentronics42 via groups.io
Sent: Monday, July 5, 2021 11:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trouble shoot and extremely stubborn 465B

After a night of trouble shooting I think I have traced it to at least the offending section if not the dead part. Putting a square wave on the channel 2 input I have what I think is the expected wave forms. At the base of Q1215I also have what seems to be a very low signal 10's of mv at the collector of Q1215 but I have almost 0 signal at the base of Q1118. I am starting to this R1202 or R 1205 might be toasted. There is however the 4.2 V dc Bias at the base of Q1118 One thing Is for sure nothing is making it through Q1118 in the J1101 to head to the trigger circuit.

Zen

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Mark Vincent
Sent: Monday, July 5, 2021 5:08 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trouble shoot and extremely stubborn 465B

Zen,

Check: Q1636, VR1824, VR4421, VR4495, VR4394 and VR4496. One of the VR is in the power supply. If Q1636 is bad, use KSP10BU. For the VRs, BZX85B9V1. The Q1636 is a 151-0367-00. These can to will be leaky between C and E. It will check as a diode. Ones with the round leads will be leaky. Ones with the square leads likely will be leaky. The VRs are 9V types that I will replace as the ones I have seen in scopes will be open.

Mark

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