tek 465b scope problem

[Aaron Kentucky]

Hi,

I'm relatively new to electronics...
I've got a tek 465b that has been working fine for about 8 months.
The other day without any sort of warning the crt failed to come on
when I started it. It still triggers, but I see nothing even when I
press the beam find button. I also happen to have another 465b from a
sour ebay transaction which has no horiz scan.

Is it beyond the capability of someone like myself to swap the crt
following some careful instructions? I know there are high voltages
involved.

Is it worth it to have a professional do this or should I just forget
about the old scope and consider buying something new? I'm starting
to realize that ebay may not be the best place for scopes...

Any opinions?

Thanks,
aaron

 

[Sam Goldwasser]

velcropaw@hotmail.com (Aaron Kentucky) writes:

Hi,

I'm relatively new to electronics...
I've got a tek 465b that has been working fine for about 8 months.
The other day without any sort of warning the crt failed to come on
when I started it. It still triggers, but I see nothing even when I
press the beam find button. I also happen to have another 465b from a
sour ebay transaction which has no horiz scan.

Is it beyond the capability of someone like myself to swap the crt
following some careful instructions? I know there are high voltages
involved.

Is it worth it to have a professional do this or should I just forget
about the old scope and consider buying something new? I'm starting
to realize that ebay may not be the best place for scopes...

It's probably not a bad CRT but an electronic problem like the HV power
supply..

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[Jay Levitt]

In article <6wishgpzhe.fsf@saul.cis.upenn.edu>, sam@saul.cis.upenn.edu
says...

It's probably not a bad CRT but an electronic problem like the HV power
supply..

Do you have the service manual? I think I've seen it on eBay for about
ten bucks. There is a pretty detailed troubleshooting flowchart for "no
visible display".

--
Jay Levitt |
Wellesley, MA | Hi!
Faster: jay at jay dot eff-em | Where are we going?
http://www.jay.fm | Why am I in this handbasket?

 

[Jim Yanik]

velcropaw@hotmail.com (Aaron Kentucky) wrote in
news:faf86ffa.0403061922.325218ae@posting.google.com:

Hi,

I'm relatively new to electronics...
I've got a tek 465b that has been working fine for about 8 months.
The other day without any sort of warning the crt failed to come on
when I started it.

Did you hear the hiss/crackle of the HV charging the CRT? If not,the HV may
have failed.

It still triggers, but I see nothing even when I

press the beam find button. I also happen to have another 465b from a
sour ebay transaction which has no horiz scan.

Is it beyond the capability of someone like myself to swap the crt
following some careful instructions? I know there are high voltages
involved.

Before you swap CRTs you need to check PS voltages,check for sweep at the
CRT neck pins,check for any vertical offset,check for Z-axis unblanking
signals(you need another scope for some of these checks.)

Is it worth it to have a professional do this or should I just forget
about the old scope and consider buying something new? I'm starting
to realize that ebay may not be the best place for scopes...

Any opinions?

Thanks,
aaron

Swapping the CRT's would require a recalibration of the scope,as CRTs do
not all have the same exact deflection sensitivities.And the CRT anode
voltage has a nasty bite.The CRT acts like a storage capacitor(Leyden
Jar),and had to be discharged before removing it from the scope.

--
Jim Yanik
jyanik-at-kua.net

 

[RJODONNELL01]

Hi:

Sorry to hear of your scope trouble ...

1. I got burned 2 for 2 on Ebay scopes

2. I have a Tek 465B and the service manual (I fixed them for a used scope
dealer a few years ago).

I will gladly assist you (walk you through the major tests, or compare readings
from my scope, etc,.

No, the CRT is very simple to swap.

If you are close to PA/OH I also repair scopes, etc., for a very reasonable
fee.

RJ