Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Judging from the attenuator blocks and the trim pots some sort of analog board but out of what? 

[Vince]

Looks like a fancy toaster controller board to me. The two big knobs are clearly to set temperature and toasting time.

[ch_scr]

Judging from the attenuator blocks and the trim pots some sort of analog board but out of what? 

Looks like a scope? with individual insulated inputs 
Edit: Interesting arrangement on the insulating transformers, can we get a closer look? Are these for data or power?

[mnementh]

ON THE BENCH TONIGHT: Temp PSU for 32in Cinema Display

Anyhoo... so after it's all done, I sit down to relax with dinner and check in here and... that damned Cinema display is fucking up again, only this time the PSU brick is doing the tick-tick failure mode. FML... 



So I bring the thing down to the dwagon-cave and pop it apart again; but for the life of me, I can't figure out what holds the aluminum heatsink on the other side to the inner plate all the semis are attached to. This means that even if I did find some questionable caps, I'd have no way of getting them in/out to replace them. I decided that rather than go all Samsonite Gorilla on the damn thing getting it apart, maybe the better idea would be to try a different PSU altogether, just to see if the problem was in the PSU or the display...

mnem
I am gonna be sore in the mornin'...   

Welp... after a dozen flawless sleep/resume cycles, I'm leaning towards the Apple PSU being at fault, not the Cinema Display. I want to go downstairs and attack the thing, but I'm having a hard time working up the Give A Fuck when I can buy just bought a fanless Meanwell LED SMPS rated exactly the same 24V/6.5A as the original for $19 off Amazon...   

https://www.amazon.com/LRS-150-24-Switching-Supply-Single-Output/dp/B018RE4CWW/

mnem
 

Uggghhh... so I sit down with my morning cuppa and... the Cinema Display is now fucking up in a different manner: it's just turning itself off every 10-20 seconds. Unplugging/replugging the DC connector seems to make the problem go away, as before. Later, after I have my breakfast, I guess I'll relocate that PSU so I can wire it direct to the monitor pigtail for further testing tomorrow morning.

Intermittent faults are the worst.   

mnem


   Fuck you, Murphy.

[tggzzz]

Judging from the attenuator blocks and the trim pots some sort of analog board but out of what? 

Looks like a scope? with individual insulated inputs 
Edit: Interesting arrangement on the insulating transformers, can we get a closer look? Are these for data or power?

The attenuator blocks and the coax connectors in the original picture should indicate the manufacturer. The angle of the board to the desk is distinctive.

Here are the insulation components, the square picture is the switching PSU, the rectangular picture the signal isolation.

[Robert763]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

One case that needs better than 1999 count (3.5 digit) is monitoring battery charge voltages especially at >20V 

[Cerebus]

The postman just came:



Did the old "hold up to the light" test to check the grind on the cutter section. Man it's good, it'll even cut paper. Tried to show it here, but you know what it's like; you'll just have to take my word that all the light blocks out with negligible pressure.



Now I have to go and find a screw to remove to test their raison d'etre.

[Robert763]

Judging from the attenuator blocks and the trim pots some sort of analog board but out of what? 

Looks like a scope? with individual insulated inputs 
Edit: Interesting arrangement on the insulating transformers, can we get a closer look? Are these for data or power?

The attenuator blocks and the coax connectors in the original picture should indicate the manufacturer. The angle of the board to the desk is distinctive.

Here are the insulation components, the square picture is the switching PSU, the rectangular picture the signal isolation.

Looks like Tektronix to me but I don't know what. A FFT analyser?

[Zucca]

The postman just came:

you and menm, you both are responsible for the $25 that just disappeared in my bank.

[tggzzz]

Judging from the attenuator blocks and the trim pots some sort of analog board but out of what? 

Looks like a scope? with individual insulated inputs 
Edit: Interesting arrangement on the insulating transformers, can we get a closer look? Are these for data or power?

The attenuator blocks and the coax connectors in the original picture should indicate the manufacturer. The angle of the board to the desk is distinctive.

Here are the insulation components, the square picture is the switching PSU, the rectangular picture the signal isolation.

Looks like Tektronix to me but I don't know what. A FFT analyser?

Yes and no, respectively

The first picture shows all of the guts except for metal and plastic. The BNC connector you can see is an output.

[mnementh]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

mnem
 woof.

[mnementh]

Today I set out on some dragon-level pc hacking... literally. My notebook needs an "B&M Key 2242 Nvme SSD".
For that subset of SSDs, they are either unavailable/obsolete, of dubious quality or overpriced. Plainly speaking, short SSDs with two slots, but not SATA-type.
Short SSDs with the "wrong slot" (but of the right type) are cheaply available - you can see already where this is going... To check if this is even feasible,
pinouts of the two variants were compared. Looks good so far, we loose 2 of 4 PCIe lanes, but that should work out.
These are negotiated on boot and only "proved healthy" ones are used. So a fall-back to less lanes is anticipated.
Pinout is mostly the same, marked in red are the only incompatible contacts. Often a used contact on one is left open on the other, easing the requirements.
Hmm, only one way to find out for sure  I guess An SSD was luckily sourced locally, a slot cut very carefully with a tiny Dremel cut off disk, a bit of fine work with knife and file...
Incompatible contacts masked off with Kapton tape, and (with sweat beads on the forehead) inserted into the notebook, taking care not to push the tape away...
Works like a charm on first try, does not even complain about missing lanes, boots from device no problem 
Now to acquire one in the size I actually want and do it all over again 

Bravissimo!!! 

I remember doing a very similar hack on a cheap SSD for my first EeePC netBook (or was it my ToughBook...? smeesh, getting old su-u-ux) back in the day... cuz 16GB was idiotic small, and anything larger was ridonculous expensive-like.

mnem
moo.

[Cerebus]

The postman just came:

you and menm, you both are responsible for the $25 that just disappeared in my bank.

I'm just glad to be able to serve another fellow traveller.

[ch_scr]

Yes and no, respectively

The first picture shows all of the guts except for metal and plastic. The BNC connector you can see is an output.

Ha! That gave it away, it's a Tektronix A6902A 2-Channel 20MHz Isolation Amplifier

[Robert763]

Yes and no, respectively

The first picture shows all of the guts except for metal and plastic. The BNC connector you can see is an output.

Ha! That gave it away, it's a Tektronix A6902A 2-Channel 20MHz Isolation Amplifier

Beat me to it. I was in  work meeting......

[dl6lr]

I was the second bidder since I am a moron and I can not resist. 590 bucks saved.
The angel on the shoulder says "shit" and the devil on the other one says "thank God".

Schroedinger lenses: The contents of the containers depends upon being the winner or second...

[tggzzz]

Yes and no, respectively

The first picture shows all of the guts except for metal and plastic. The BNC connector you can see is an output.

Ha! That gave it away, it's a Tektronix A6902A 2-Channel 20MHz Isolation Amplifier

Close enough. Is a "B" with the normal-size 500V probes. The 3kV probes are too big, unless you want to hang them on the dangerous bits before energising those bits.

[Vince]

For the wooden floors, the sticky will go as soon as the oil polymerises, which is helped by heat, and a lot of buffing will help as well, though time is the more important factor, along with the heat, to promote the cross linking of the linseed oil in there.

3PM here, been 24 Hours since oiling yesterday. Stickiness is gone, phew ! 
Now dry and smooth to the touch, feels like wood not like glue anymore...
Well I guess if I were critical I could say it's still sticky in some way, in that if you walk on it it feels like an "anti-slip" surface or something... walking with socks on, and trying to slide o nit, you don't go very far, it kinda brakes you. Which is cool, reduces the risk of accident ! 

Definitely the kind of security I would want on y future stairs, to get to the attic, in a million years, when the attic is done and I actually have a case... for a staircase ! 

Also : after 24 hours, my very oily rags, well soaked... have NOT self ignited and combusted ! I am SO disappointed, no fun, I want my money back !!!
It's like buying a big expensive cap, polarizing it in reverse and it does NOT explode ! That's just too cruel and it just can't be !!! 

[mnementh]

DISQUALIFIED ! 

The Fluke 87 is hardly a cheap bare bone meter like the 10/11/12 are ! 
the 87 s a very nice meter, good accuracy, high count/resolution, good features, and expensive.

I would love to add one to my collection (have 4 old Fluke DMMs in all), but here at least, the Fluke brand markup is too much. They aren't good enough value for money. That's why I prefer buying Metrix MX 53/54/56, way better value for money overall.

I can't justify spending 90 euros on an old Fluke 73 say, or 75 ot 77 even, when the same money can get me a MX54/C for example. It just does not compute at all... 
So the few Flukes I do have, are only with me because I was lucky enough to find them at price point that makes sense.
If I can find a nice 87V for a price I like, I would buy it. Well, not now of course, no money for TE atm....

Of the 10 Fluke DMM's in my stash the 87 is the only one I bought new in 1997. Yes, it wasn't cheap.

I've never regretted the money spent on FLUKE. EVER. I got my 87 when I was working for Philips while working my way through my first degree, before they were even available for sale. I paid for it out of 6 paychecks, and it was my go-to meter for 30 years. IMHO, that is unbeatable ROI.

mnem
There's a reason this emoji looks like a FLUKE 87. 

[Zucca]

Schroedinger lenses: The contents of the containers depends upon being the winner or second...

Looking at the winner stats I suspect it is a bot and not a real human.
I need NEO to win the battle against the machines.

[mnementh]

Anyway, enough display porn and meters... Back to tweaking a recent unnecessary addition to the herd.   

Pat said it best...

C'mon - we in this thread all know that the correct hierarchy of acquisition of things is WANT > Need.     -Pat

mnem
*toddles off in search of caffeine dietary supplement*

[Zucca]

Pat said it best...

C'mon - we in this thread all know that the correct hierarchy of acquisition of things is WANT > Need.     -Pat

mnem
*toddles off in search of caffeine dietary supplement*

to me the situation:

money>want>>need

is the worst case, because it quickly becomes

want>need>money

and the process can not be reversed.

[Vince]

Trying to be a good boy, do somethging productive, and sit down for a while to order all the caps for my 2467 scope PSU.

It's not going well, at all.

To speed up the process, I ma trying to order all values from the same brand and series. For instance Panasonic 'FR' series, on Farnell (same problem on TME).

Values are either out of stock, or only one single cap left.... freaking CAPS, not CPUs !!! 

Can the world go round again please ?!   

Looks like I will have to search different brands and series for every of the XXX caps I need for this PSU, oh I am happy 

Just saw in the news that Shenzhen is now in "quarantine" / lock-down mode due to COVID again.... sure is not gonna help the situation !!! 

[mnementh]

The postman just came:    

you and mnem, you both are responsible for the $25 that just disappeared in my bank.

I'm just glad to be able to serve another fellow traveller.

https://www.ebay.com/itm/393658775351   Hmmm... 1 left, just like when I bought mine.   

         vs PZ-58:   

https://www.ebay.com/sch/i.html?_from=R40&_nkw=PZ-57&_sacat=0&_sop=15

Got my PZ-57 from here: https://www.ebay.com/itm/323655992795

Youuuu're wellll-commmme!!!

mnem
*Toolish ol' dwagon*

[tggzzz]

Anyway, enough display porn and meters... Back to tweaking a recent unnecessary addition to the herd.   

Pat said it best...

C'mon - we in this thread all know that the correct hierarchy of acquisition of things is WANT > Need.     -Pat

Extra information: before buying the a6902b I already had an a6900 with (only) one channel working. I've never used it

So both "herd" and "unnecessary" are justified.

I wonder how much I'll get for that 6902?