Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 1831790 times)

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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10550 on: May 12, 2018, 12:03:20 pm »
These 24x5 repair notes are sufficiently useful that we would benefit from them being on some 24x5 repair thread, not merely buried in theses 10,000+ posts!

Thanks.

Here's links to a pdf parts list, a pdf dissertation on rebuilding the Tek 24xx DC-DC converter, a page that helped me with links to a lot of other useful info on repairing the 2465, and here is KO4BB's archive of service manuals and resources for the 2465B/2467B. Please don't forget to give back a little via the button; hosting those documents isn't free and you can skip Starbucks or McD's for a day. :-+

I think that stuff has already been posted in the 2465 repair thread.
An old gray beard with an attitude.
 

Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10551 on: May 12, 2018, 12:09:59 pm »
The A5 board: This is a 2465. The EAROM chip in the Buffer (Option) board in my 2465 DMS does take intermittent checksum errors so there seems to be some truth in that rumor.

At what point in the operation is that error visible? Power up, after 5mins inactivity which IIRC causes a write to the EAROM, etc?
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10552 on: May 12, 2018, 12:15:23 pm »
mnem, those 2 parts are exactly what I need.   :-+ You still have my snail mail address, right? Isn't great when a fellow TEA'er can help each other with their addiction?  :-DD Hopefully I can return the favor one day.  :-/O
   
Totally agree and I think it goes on a lot, sometimes in the background rather then publicly as well, I know that from personal experience  :-+
Who let Murphy in?
 

Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10553 on: May 12, 2018, 12:15:37 pm »
The A5 board: This is a 2465. The EAROM chip in the Buffer (Option) board in my 2465 DMS does take intermittent checksum errors so there seems to be some truth in that rumor.

At what point in the operation is that error visible? Power up, after 5mins inactivity which IIRC causes a write to the EAROM, etc?

It takes a "Buffer Board Checksum Error" on initial power up when it goes thru the self tests. It clears and the scope appears to operate normally. That EAROM stores the cal data for the DMM option and the Counter/Trigger option only. It does not affect the mainframe. Despite that checksum error I have been able to calibrate the DMM and the Counter and they appear to operate OK.
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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10554 on: May 12, 2018, 12:31:32 pm »
In between fixing the 465 and this new 2465 I was able to complete the power supply modification to the Fluke 8000A DMM. It now has a regulated 5V supply built up and installed. It's kind of a bodge but it does work and it is secure and safe. Just to the left of the new board are the 7815 and 7915 regulators for the +/- 15V supplies. I've had it on for several hours now and the measurement drift for all practical purposes is gone. All that's left is final check of calibration and it's a wrap. 
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Offline AF6LJ

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10555 on: May 12, 2018, 12:38:50 pm »
Good deal, and a well executed mod.
Sue AF6LJ
Test Equipment Addict, And Proud Of It.
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10556 on: May 12, 2018, 01:46:32 pm »
That looks like a neat installation and solution to the problem, well done.
Who let Murphy in?
 

Offline factory

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10557 on: May 12, 2018, 02:51:51 pm »
Our ebay fraudster is back again, this time using the account ahimsaann. Same items listed as last week.
If we can spot things like this, why cant Ebay?

Yet another legitimate ebay seller has been hacked by the fraudster;
https://www.ebay.co.uk/sch/angel_lottie/m.html?item=292560734882&hash=item441dfa8aa2%3Ag%3Aok0AAOSwrf5a9tIC&rt=nc&_trksid=p2046732.m1684
Looking at the completed listings confirms it.

David
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10558 on: May 12, 2018, 03:06:23 pm »
Yes been reporting that wanker all day.

Edit: Only just got my monitor back on my desktop so have been offline for a few hours. Ran out of mains leads as I had to give one away with something I sold. Ordered a load from CPC and a new socket block as well which just arrived. Don't have to swap plugs around all the time now. Had to get a 10 way and I've only got 1 socket free now :D
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10559 on: May 12, 2018, 03:06:49 pm »
Our ebay fraudster is back again, this time using the account ahimsaann. Same items listed as last week.
If we can spot things like this, why cant Ebay?

Yet another legitimate ebay seller has been hacked by the fraudster;
https://www.ebay.co.uk/sch/angel_lottie/m.html?item=292560734882&hash=item441dfa8aa2%3Ag%3Aok0AAOSwrf5a9tIC&rt=nc&_trksid=p2046732.m1684
Looking at the completed listings confirms it.

David
I wonder if the other account holders were also away, thus giving this fraudster an opportunity?
Who let Murphy in?
 

Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10560 on: May 12, 2018, 03:14:29 pm »
I wonder if the other account holders were also away, thus giving this fraudster an opportunity?

I had speculated that myself.

I don't know, as I've never had cause to use it, but I wonder if when you've set an "This ebay seller is away until XYZ" message that you can cancel it? If so, a fraudster could look for accounts with a 'holiday' message, see if they have a username and password from one of the many breaches of re-used passwords, take over the account, remove the 'holiday' message and install their standard connection of fraudulent listings.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10561 on: May 12, 2018, 03:18:56 pm »
You can indeed cancel that.

Reused passwords is a good attack vector. There are plenty of databases of leaked passwords out there and the asshats who reuse them tend to not get the point, blame it on the evil hackers and carry on with their passwords.

You should have seen the shit we got when we started testing passwords against known password corpus. Oh you're not allowed "password1". Tough shit!
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10562 on: May 12, 2018, 04:19:44 pm »
mnem, those 2 parts are exactly what I need.   :-+ You still have my snail mail address, right? Isn't great when a fellow TEA'er can help each other with their addiction?  :-DD Hopefully I can return the favor one day.  :-/O

To address your concerns....I have a 2465 DMS and I am VERY familiar with the squirrel cage fan and that colet assembly. I was able to get mine apart without breaking it with lubricant and careful prying. That was 2 years ago when I completely re-capped both supply boards. The fan motor in that scope is a little noisy upon initial power up but quickly quiets down after a few minutes. That Siemens fan motor is unobtanium and stupid complex to rebuild. So as long as it works I'm leaving it alone. The fan in this new 2465 is quiet...so far.

I've had this new 2465 on for several hours and I've also gone thru several power cycles. Absolutely NO issues except for the mentioned sweep cal being slightly off. I would think if there was an intermittent issue I'd see it by now. Later today I'm pulling the covers and give it a good visual check and measure the supply voltages at J119 on the main board. If they are OK I'm NOT pulling the power supply boards.

The A5 board: This is a 2465. The A5 is pin thru hole board with almost NO tants or other caps. Very much unlike the 2465A and 2465B which have the SMT A5 board. Also, the cal data is in an EAROM which doesn't require a backup battery. So no worries here but I understand that those EAROM chips supposedly have a finite read/write cycle and then start crapping out. The EAROM chip in the Buffer (Option) board in my 2465 DMS does take intermittent checksum errors so there seems to be some truth in that rumor.

I'll post some pix later today when I pull it apart.     

Oh, brain fart.  :palm: I've been trying to coach neo on his 2465B; in fact, part of that post was cut/paste from those conversations.  |O Dumbass; that's what I get for trying to put up a long tech post at 00:Dark-thirty in the AM.   :blah:

As I say with all my advice, please take in the spirit in which it is offered: Use what is helpful, disregard what is irrelevant, and if you find something offensive please just assume I was being daft, as I very RARELY intend to be mean.  :scared:


These 24x5 repair notes are sufficiently useful that we would benefit from them being on some 24x5 repair thread, not merely buried in theses 10,000+ posts!

Thanks.

Here's links to a pdf parts list, a pdf dissertation on rebuilding the Tek 24xx DC-DC converter, a page that helped me with links to a lot of other useful info on repairing the 2465, and here is KO4BB's archive of service manuals and resources for the 2465B/2467B. Please don't forget to give back a little via the button; hosting those documents isn't free and you can skip Starbucks or McD's for a day. :-+

I think that stuff has already been posted in the 2465 repair thread.

Yup, that's where I found those links... after doing a deep dive years ago. I just put the ones I felt yielded the most useful information together in one sentence in my repair notes to be able to cut/paste later; I really should have edited the one link to return KO4BB's resources for the 2465, which he ALSO has oodles of, along with all sorts of OTHER useful stuff as well for us boat anchor enthusiasts. But as I said earlier... 1AM brain fart.  :-//


mnem, those 2 parts are exactly what I need.   :-+ You still have my snail mail address, right? Isn't great when a fellow TEA'er can help each other with their addiction?  :-DD Hopefully I can return the favor one day.  :-/O
   
Totally agree and I think it goes on a lot, sometimes in the background rather then publicly as well, I know that from personal experience  :-+

Good, just wanted to be sure. Yup, still have your address; I just haven't decided what all I'm putting in the box yet.  :-DD

I'm glad to help; I know it's a small thing in the grandeur of Ifni's scope, but I'd rather make a small positive difference than a big negative one, or none at all.

As I tell my friends in the RCGroups forums; Pay It Forward. It's what I'm doing, and a lot better than paying it back, IMO. I mean really... the last thing I need is ANOTHER box of random junk to sort and archive right now.   ;)


mnem
Don't git any on ya!




 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10563 on: May 12, 2018, 04:27:32 pm »



In between fixing the 465 and this new 2465 I was able to complete the power supply modification to the Fluke 8000A DMM. It now has a regulated 5V supply built up and installed. It's kind of a bodge but it does work and it is secure and safe. Just to the left of the new board are the 7815 and 7915 regulators for the +/- 15V supplies. I've had it on for several hours now and the measurement drift for all practical purposes is gone. All that's left is final check of calibration and it's a wrap.

I see you went with a different transformer than the ones I sent; I assume the screw tab was what you needed. I tried to find onein my stuff, but the only thing I had that wasn't already earmarked was this huge thing from a car battery charger.

Hope you can find other use for what I sent; there'll be more on its way soon.  :o


mnem
In other news... *WHUMMMP!!!*
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10564 on: May 12, 2018, 04:36:29 pm »
You can indeed cancel that.

Reused passwords is a good attack vector. There are plenty of databases of leaked passwords out there and the asshats who reuse them tend to not get the point, blame it on the evil hackers and carry on with their passwords.

You should have seen the shit we got when we started testing passwords against known password corpus. Oh you're not allowed "password1". Tough shit!

One of the first things they taught us in the forensics class I took a decade ago was "It's always easier to hack the wetware". This means, among other things,  DON'T kill yourself trying to decrypt the passwords in the software; scan the computer for the text file where the user keeps his websites & passwords in plain text.  :palm:


mnem
"If your attacker can gain physical access to a PC, they pretty much OWN it. Plan your network accordingly."
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10565 on: May 12, 2018, 04:39:40 pm »
Usually in the chrome, Firefox and IE saved password usual hangouts :)

We recently started sending all our users phishing links and send the idiots who click them to re-education camps. I suggested concentration camps but they frowned and said “too soon” :D

As for physical access, dousing the company plants in roundup solved the physical security problems. Straight in the bin rather than wedging the doors open.

I love that side of the job.
 

Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10566 on: May 12, 2018, 04:57:02 pm »
Usually in the chrome, Firefox and IE saved password usual hangouts :)

We recently started sending all our users phishing links and send the idiots who click them to re-education camps. I suggested concentration camps but they frowned and said “too soon” :D

As for physical access, dousing the company plants in roundup solved the physical security problems. Straight in the bin rather than wedging the doors open.

I love that side of the job.

You are Simon Travglia, and I claim my £5.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10567 on: May 12, 2018, 04:58:08 pm »
One of the first things they taught us in the forensics class I took a decade ago was "It's always easier to hack the wetware". This means, among other things,  DON'T kill yourself trying to decrypt the passwords in the software; scan the computer for the text file where the user keeps his websites & passwords in plain text.  :palm:

And if that fails, "rubber hose" decryption techniques are often effective.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Online BravoV

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10568 on: May 12, 2018, 05:05:44 pm »
These 24x5 repair notes are sufficiently useful that we would benefit from them being on some 24x5 repair thread, not merely buried in theses 10,000+ posts!

Thanks.

Here's links to a pdf parts list, a pdf dissertation on rebuilding the Tek 24xx DC-DC converter, a page that helped me with links to a lot of other useful info on repairing the 2465, and here is KO4BB's archive of service manuals and resources for the 2465B/2467B. Please don't forget to give back a little via the button; hosting those documents isn't free and you can skip Starbucks or McD's for a day. :-+

I think that stuff has already been posted in the 2465 repair thread.

Yep, its there and many others buried in that gigantic thread.

Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10569 on: May 12, 2018, 05:06:00 pm »



In between fixing the 465 and this new 2465 I was able to complete the power supply modification to the Fluke 8000A DMM. It now has a regulated 5V supply built up and installed. It's kind of a bodge but it does work and it is secure and safe. Just to the left of the new board are the 7815 and 7915 regulators for the +/- 15V supplies. I've had it on for several hours now and the measurement drift for all practical purposes is gone. All that's left is final check of calibration and it's a wrap.

I see you went with a different transformer than the ones I sent; I assume the screw tab was what you needed. I tried to find onein my stuff, but the only thing I had that wasn't already earmarked was this huge thing from a car battery charger.

Hope you can find other use for what I sent; there'll be more on its way soon.  :o


mnem
In other news... *WHUMMMP!!!*

Yea, while I was waiting for your care package to show up I found that transformer in my stash. Forgot I had it. But I did wait until your package showed up before deciding what to use. The 8000A board in that area has large thru holes which I assume are for the battery option. I wanted to utilize at least one of those holes to bolt down the transformer rather than relying on epoxy to hold it in place. So that's how the decision was made. But I certainly appreciate what you sent me and I'm sure those parts will be useful on future projects.  ;D
An old gray beard with an attitude.
 

Offline GerryBags

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10570 on: May 12, 2018, 05:06:51 pm »
I had an Ebay purchase that was totally non-suspect turn out to be a scam. Got a message after the sale saying that he was away on holiday so he'd give me a refund...? That made no sense, so I was careful about clicking for a while, and sure enough a fake Paypal notification from the seller's Google mail account turns up hoping I'd use the link in the email. Scum bags.

Anyway, here's a shot of the 2467B today.... still hasn't exploded! It has already shown me that the TTL output of my LG function gen has gone a bit funky, and it's square wave is only square at about 1 KHz. I'll have to have a look at that soon. The service manual for the 2467B & 2465B turned up today, only a reprint, but it has got 11" x 14" prints of the pull-outs.

Hopefully by this time next week I shall have a fully working 2465B sitting on top of the 2467B.
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10571 on: May 12, 2018, 05:14:25 pm »
Usually in the chrome, Firefox and IE saved password usual hangouts :)

We recently started sending all our users phishing links and send the idiots who click them to re-education camps. I suggested concentration camps but they frowned and said “too soon” :D

As for physical access, dousing the company plants in roundup solved the physical security problems. Straight in the bin rather than wedging the doors open.

I love that side of the job.

You are Simon Travglia, and I claim my £5.

I am much much worse than the BOFH. I fired someone and revoked their door card while they were out for lunch. This was for calling me Stalin because I made them follow process to the letter.
 

Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10572 on: May 12, 2018, 05:16:04 pm »
These 24x5 repair notes are sufficiently useful that we would benefit from them being on some 24x5 repair thread, not merely buried in theses 10,000+ posts!

Thanks.

Here's links to a pdf parts list, a pdf dissertation on rebuilding the Tek 24xx DC-DC converter, a page that helped me with links to a lot of other useful info on repairing the 2465, and here is KO4BB's archive of service manuals and resources for the 2465B/2467B. Please don't forget to give back a little via the button; hosting those documents isn't free and you can skip Starbucks or McD's for a day. :-+

I think that stuff has already been posted in the 2465 repair thread.

Yep, its there and many others buried in that gigantic thread.

My trials and tribulations in getting the 2465 DMS up and running are buried in that thread too.
An old gray beard with an attitude.
 

Online BravoV

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10573 on: May 12, 2018, 05:19:19 pm »
My trials and tribulations in getting the 2465 DMS up and running are buried in that thread too.

Yep, I'm fully aware of that, much appreciated  :-+, still much-much better than spreaded across multiple threads and multiple sections.

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #10574 on: May 12, 2018, 05:20:18 pm »
There needs to be a “repair stories” site I think. Rather than a forum that is.
 


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