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2445A Sweep and Other Questions


 

Hi,

I acquired a 2445A a few years back and never switched it on until now. I am now starting to look at it for the first time and there are a couple of issues, but I have no scope fixing experience. Plus it's been a while since I did any fault finding on anything truly electronic.

So, I am trying to assess whether I should sell this on Ebay (UK) as a broken item, or whether I should take a shot at fixing it up.

I have powered it up and there are no reported faults, plus the scope traces appear as they should, as well as on screen characters. However, after a warm-up period (5-10 mins) the sweep stops and I am left with just a vertical trace. Using the J119 test points I can see that the supplies all look good with a DVM, but using Pico scope (laptop based scope) I can see some ripple on the supplies. I have yet to determine whether the ripple is in spec. (Though, I know where the info for that is in the manual)

Where do you think I should start with this? Should I just do a bulk capacitor swap out an ask questions later, or are there a few particular ones I should go for?

I should also say that some of the on-screen characters seem to get corrupted after a while as well.

Any opinions on where I should go with this would be appreciated.

Thanks

Paul


 

Hi,

Fix it and tell us about it.

How large is the ripple? Everyone seems to recommend changing the caps in the power supply. You say after warmup, then the problem starts. CAPS??

The manual is online. 2445 and 2465 are very similar. On EEVBlog, another fella is working na 2465.

Larry

On Aug 14, 2019, at 3:04 PM, Paul Gallimore <paulmk22@...> wrote:

Hi,

I acquired a 2445A a few years back and never switched it on until now. I am now starting to look at it for the first time and there are a couple of issues, but I have no scope fixing experience. Plus it's been a while since I did any fault finding on anything truly electronic.

So, I am trying to assess whether I should sell this on Ebay (UK) as a broken item, or whether I should take a shot at fixing it up.

I have powered it up and there are no reported faults, plus the scope traces appear as they should, as well as on screen characters. However, after a warm-up period (5-10 mins) the sweep stops and I am left with just a vertical trace. Using the J119 test points I can see that the supplies all look good with a DVM, but using Pico scope (laptop based scope) I can see some ripple on the supplies. I have yet to determine whether the ripple is in spec. (Though, I know where the info for that is in the manual)

Where do you think I should start with this? Should I just do a bulk capacitor swap out an ask questions later, or are there a few particular ones I should go for?

I should also say that some of the on-screen characters seem to get corrupted after a while as well.

Any opinions on where I should go with this would be appreciated.

Thanks

Paul



 

On Wed, Aug 14, 2019 at 5:51 PM Paul Gallimore <paulmk22@...> wrote:

So, I am trying to assess whether I should sell this on Ebay (UK) as a
broken item, or whether I should take a shot at fixing it up.
Definitely fix'er up, there's nothing like the feeling of restoring a
beautiful bit of test gear like this. Gotta be careful though, it's hard to
stop once you fixed one :).


 

I fixed the one I purchased from eBay with the help from goys here! I'm
sure you can fix it!
Now, I'm not an expert, but in my case it was -after many days and emails
and searches on the web....- easy fix (if you can call it that).
If I can help with something specific I'll help.
My problem was - see my youtube here:


Gooood luck!

Tony

On Wed, Aug 14, 2019 at 4:51 PM Paul Gallimore <paulmk22@...> wrote:

Hi,

I acquired a 2445A a few years back and never switched it on until now. I
am now starting to look at it for the first time and there are a couple of
issues, but I have no scope fixing experience. Plus it's been a while since
I did any fault finding on anything truly electronic.

So, I am trying to assess whether I should sell this on Ebay (UK) as a
broken item, or whether I should take a shot at fixing it up.

I have powered it up and there are no reported faults, plus the scope
traces appear as they should, as well as on screen characters. However,
after a warm-up period (5-10 mins) the sweep stops and I am left with just
a vertical trace. Using the J119 test points I can see that the supplies
all look good with a DVM, but using Pico scope (laptop based scope) I can
see some ripple on the supplies. I have yet to determine whether the ripple
is in spec. (Though, I know where the info for that is in the manual)

Where do you think I should start with this? Should I just do a bulk
capacitor swap out an ask questions later, or are there a few particular
ones I should go for?

I should also say that some of the on-screen characters seem to get
corrupted after a while as well.

Any opinions on where I should go with this would be appreciated.

Thanks

Paul




 

Yes, I think this is what I will do. The scope is obviously old enough that the caps will have leaked, so I'll go with that as a starting point. I'll let everybody know how it goes.

Thanks.


 

Take lots of pictures and video, while disassembling your scope and
notes...etc! Replace what is bad, don't fix that isn't broken!
These scopes are very good quality and few parts here and there are needing
attention but that is it!

On Thu, Aug 15, 2019 at 2:48 AM Paul Gallimore <paulmk22@...> wrote:

Yes, I think this is what I will do. The scope is obviously old enough
that the caps will have leaked, so I'll go with that as a starting point.
I'll let everybody know how it goes.

Thanks.




 

OK, message understood. Steady as she goes.

Sent by Paul Gallimore

From: Tony Fleming
Sent: 15 August 2019 14:43
To: [email protected]
Subject: Re: [TekScopes] 2445A Sweep and Other Questions

Take lots of pictures and video, while disassembling your scope and
notes...etc! Replace what is bad, don't fix that isn't broken!
These scopes are very good quality and few parts here and there are needing
attention but that is it!

On Thu, Aug 15, 2019 at 2:48 AM Paul Gallimore <paulmk22@...> wrote:

Yes, I think this is what I will do. The scope is obviously old enough
that the caps will have leaked, so I'll go with that as a starting point.
I'll let everybody know how it goes.

Thanks.