Test Equipment Anonymous (TEA) group therapy thread

[m k]

TV REPAIR

We have picture !!! 

The old LED strips were much easier to remove than I had feared. The adhesive wasn't that adhesive... 

The new strips came with adhesive already on them, and it was quick and easy to get them positioned properly, no drama 

Put it all back together and the LCD looks like it survived, can't see any defect or weird thing going on.

My second and first successful flat TV repair. I hate these things with a passion, hopefully next one won't be before... as many years as possible.
Huge/impractical/impossible to handle, not designed to be serviced/taken apart without breaking plastic clips. LCD screen that consistently requires to be removed in order to get access to the LED strips....  big fail from end to end.
I don't care how big or expensive or "smart" these TVs are... they are all made the same, all junk. If people are crazy enough to pay more than 50 Euros for one, their problem.
I can't believe this piece of garbage is still on sale right now for 1650 Euros, it just blows my mind, truly does 

Anyway, happy to see that I somehow managed to fix one of these things, and even more happy that it can now get the fuck out of my lab/living room, it fills half the room !! 

Need the space to walk across the room, and need space on the bench for more interesting activities.

Gonna call my friend, hopefully he can take this thing away from me ASAP and free the space....

I think the real cost in those large screen TV's is just that, the large screen. I don't have any idea what they cost to make, but I do know that if you were to try and buy a replacement screen, they cost a small fortune. That said, however, I suspect the high retail price is more than likely to be a significant magnitude higher than it need to be due to the one-up-man ship factor that is so rife in world economics today. (Ducks to miss all the incoming rotten wellies).

Delta PYE.

[med6753]

5245L update:

It is now upside down and open, ready to take a new IEC inlet. Pics are in phone, but I need to cook dinner first. And perhaps finish the job, before I post about it.

But a little teaser never hurt, did it?

If you want to re-cap the PSU I have done a similar 5248L and I can provide pictures.

[Neomys Sapiens]

Some other new aquisitions of the last days:

- A splitter/combiner with a useful bandwidth and rated for 40W and really cheap at under 20.- all inclusive

- A little heatwire anemometer, which, if functional, would come very handy at work, as I have to evaluate whether the protective grills intended for a refit reduce the airflow too much or not.

- A very strange key for electrical cabinets. Three of it's four sides are like nothing that I've ever seen. Usage for electrical cabinets is stated by former owner.

- And some vintage Siemens appnotes which somehow looked interesting (one is the original appnote for the TCA695)
From this seller I included a really strange plug. Also something which I've never seen before.

So, fun, education and some really useful stuff, all served for some small change.

[Neomys Sapiens]

Edit: one thing I was really not impressed with. Whoever trimmed off the leads on it at the factory used blunt as hell cutters. All the leads are flattened at the end meaning you need to trim them more before desoldering otherwise the legs won't go through the holes   

That may not be blunt cutters, that may be a cutter that was designed to not only cut, but lead-form as well to make sure that the part didn't pull out before soldering. I used to have a pair like that, many years ago.

The flattening-type of clinch was probably specific to powered tools, as it would take an unreasonable amount of force to effect such a deformation on some of the harder component leads (like diodes and resistors >1W). But I have a pliers which cut the lead to length and makes a sharp bend in one action (Belzer 2458K). But one has to watch the orientation of the pliers, as a sideways bend, i.e. out of the components axis, would not achieve the desired effect.

[mansaxel]

5245L update:

Connector replaced, works well on the mains side.

Proceeded to verification; found several voltages to be off, the -6,9 and 17,6V. But! I must have gotten the wrong edition paper manual. Several resistors on the A7 board (DC regulator) have clearly different, much higher values than the schematic thinks they should have. Counter is most likely newer than manual.

Scanned manual I have is similar. 

Finally found the one on the Keysight site, which is new enough. I have most likely not blown anything;  the voltages are within specification.

Will do a brief function check, put the covers back on, and come back with a post detailing my actual repair.

[ch_scr]

Ok, here it finally is - the Racal Dana 9300 discrete RMS converter core, recreated in LTspice. The only real difference is the switches (changed from original FET to LTspice included modern stuff). But I've found spice models for all the other stuff, even diode coefficients for the "Hot carrier" 5082-2811 diodes published by HP themselves The thing even works  and gives close-to expected RMS value outputs. If you were as curious as I, to what makes this 1980's special tick - knock yourself out, the file is included below 

[cyclin_al]

Look at the chemicals used in Teflon manufacturing next, it's "PCB oil" (not circuit board related) all over again - just harder to replace this time 
Then look at the Arsenic dust canada has in underground mines on a biiig lake shore. Then look at uranium manufacturing residue and let's not get started on spent fuel reprocessing Only upside is, we'll make the place inhabitable for humans looong before it's inhabitable for "nature".

Yes, we have a lot to deal with to make things inhabitable.

Part of it is the learning curve, we (humankind in general) need to be better at doing our homework.  Teflon is just a subset of the chloro- flouro-carbon problem.  No one bothered to really understand those chemicals, or maybe covered up the downsides?  They were certainly marketed as miracle products.  Nasty stuff.  Small steps are being taken.  Flourinated ski waxes were banned for world cup and Olympic races, and throughout europe at the beginning of 2022.  As most production of ski waxes is in Europe, that stops the new production.  That is a tiny token step in the right direction.  That still leaves a lot of skiing where those nasty things are still being used.  Yep, those waxes are still in use in Canada, except at my local club; that was a painful transition.

The teflon on cookware is still a much bigger use.  SWMBO still abuses it since those are actually serious warnings on the cookware.  Food or water keeps the cookware temperature below the temperature that the teflon vapourizes.  Nothing in the cookware on the stove quickly leads to vapourized teflon.  Why bother manufacturing the stuff if everyone is going to turn it into vapour anyways? 

You must be thinking of the Asbestos (not arsenic) mine in Canada.  Mining stopped in 2011.  That does no good, as the stuff that is already mined is still being exported and put into various products. 

Do we even know how nasty lithium mining is?

[bd139]

Ok, here it finally is - the Racal Dana 9300 discrete RMS converter core, recreated in LTspice. The only real difference is the switches (changed from original FET to LTspice included modern stuff). But I've found spice models for all the other stuff, even diode coefficients for the "Hot carrier" 5082-2811 diodes published by HP themselves The thing even works  and gives close-to expected RMS value outputs. If you were as curious as I, to what makes this 1980's special tick - knock yourself out, the file is included below 

Ooh very nice. I shall queue that one in my todo list to play with for tomorrow. Thanks for your efforts on reverse engineering this

[tggzzz]

I had a summer job at university stuffing boards with one of those bloody things . I lasted about a week before they promoted me much to the disgust of people who had been doing it for 30 years.

Presumably you were sufficiently incompetent at board stuffing.

[bd139]

I had a summer job at university stuffing boards with one of those bloody things . I lasted about a week before they promoted me much to the disgust of people who had been doing it for 30 years.

Presumably you were sufficiently incompetent at board stuffing.

I was told I was affecting team morale. I learned a lot about politics and competence in those 6 weeks.

[mnementh]

Unsurprised. I just paid fees and handling on some swiss cakes a relative sent that I could have got up the road for £1 less   

Seems like a legal form of highway robbery. 

Yeah, wait'll you pay FEDEX a $80 "brokerage fee" for $12 in imaginary VAT that you already paid the vendor in full... because the package has her anniversary present in it.

Count yourselves lucky, my friends.

mnem
They took my thumbs.

[tautech]

I had a summer job at university stuffing boards with one of those bloody things . I lasted about a week before they promoted me much to the disgust of people who had been doing it for 30 years.

Presumably you were sufficiently incompetent at board stuffing.

I was told I was affecting team morale. I learned a lot about politics and competence in those 6 weeks.

Translation = Get that little smart arse outta here !

What else did I miss overnight....Vince, although you might now hate them simple fixes on flat screen anythings can be money for jam. That was at one time mnem's MO, grabbing anything that might be half decent from the curbside to fix and flip.

[srb1954]

5245L update:

Connector replaced, works well on the mains side.

Proceeded to verification; found several voltages to be off, the -6,9 and 17,6V. But! I must have gotten the wrong edition paper manual. Several resistors on the A7 board (DC regulator) have clearly different, much higher values than the schematic thinks they should have. Counter is most likely newer than manual.

Scanned manual I have is similar. 

Finally found the one on the Keysight site, which is new enough. I have most likely not blown anything;  the voltages are within specification.

Will do a brief function check, put the covers back on, and come back with a post detailing my actual repair.

During the life of this product it went through quite a few changes. I have both a series 504 and series 716 version and they have very significant internal differences. I managed to download a service manual for the series 716 but never found anything online for the series 504.

What is the serial number of your 5245L?

Maybe you need to try Artek Manuals to see if they have the manual appropriate to your unit.

[Vince]

What else did I miss overnight....Vince, although you might now hate them simple fixes on flat screen anythings can be money for jam. That was at one time mnem's MO, grabbing anything that might be half decent from the curbside to fix and flip.

Well, this TV is worth 1650 bucks brand new, so yes I would be delighted to sell it and pocket the money ! 

But it's not mine...


Finding stuff on the curb ... there is no such thing in France. That's the problem. What used to be on the curb many years ago, now people sell on leboncoin.fr and want 50 to 100 Euros / USD  for it.
You can't get old broken electrical / electronic stuff from the dump yard because nowadays all the consumer electrical appliances are stored in a locked container with cameras watching you. Strictly forbidden to grab stuff that others have brought in. Silly, but that's how it is.

There is no source of cheap broken stuff to fix (or just salvage parts from), that's the big problem here....

[Zoli]

... CA accelerator is acetone ...

No, acetone is not an accelerant for CA polymerisation. It is often used as a solvent for the actual accelerator - as is hexane - but the accelerant is generally either an amine such as N,N-dimethylbenzylamine, N,N-diethyl-toluidine or N,N-dimethyl-p-toluidine, or a disulphide such as dibenzodiazyl disulphide, 6,6-dithiodinicotinic acid or 2,2-dipyridal disulphide. Calixarene compounds can also be used to assist polymerisation with acidic items to be bonded such as wood, leather and paper. There are more accelerators and the choice of which is used depends very much on the application. Some are unpleasantly toxic.

CA accelerator mixtures may contain acetone, but acetone itself is NOT a CA accelerant.

Thanks for the correction; looks like lately I'm blind:

[mansaxel]

5245L report:

As some might remember, this is the start of my trip:



I ordered a bag of IEC inlets and waited. And waited. And waited. Finally messaged seller who realised they'd been paid and not shipped, so they improved radically.

Old one had to come out. Cerebus guessed right; it was Bakelite or similarly brittle; so would crack with gentle applications of side cutters. Finally, the rivets were easy to cut and remove.



Crumbs indeed;



So, how to fit new one? My rivet collection was lacking, and I wanted something reversible, Screw and (possibly rivet-)nut woulda been best, sheet metal screw borderline gorilla. Loose nut on inside near impossible to fit.  Compromise turned out to be M4 tap:



This is minimal impact on the chassis, reversible, and functional. I'm happy:



The old anti-HF caps were brittle and large. I had 2 10nF X2 caps in storage, so swapped them out.



Soldered inductor leads, ground strap and capacitor legs to undressed Fastons and then fitted them to the connector.
There's not much place left:



Then on to testing, with the usual "match the manual to the instrument" rabbit hole, as noted earlier tonight:

Proceeded to verification; found several voltages to be off, the -6,9 and 17,6V. But! I must have gotten the wrong edition paper manual. Several resistors on the A7 board (DC regulator) have clearly different, much higher values than the schematic thinks they should have. Counter is most likely newer than manual.

Scanned manual I have is similar. 

Finally found the one on the Keysight site, which is new enough. I have most likely not blown anything;  the voltages are within specification.

Will do a brief function check, put the covers back on, and come back with a post detailing my actual repair.

Function check:

I had some issues with getting it to trigger; it is a bit deaf. The manual talks about adjusting input gain and it being necessary if you've poked those gorilla thumbs in the DC supplies. I actually replaced a 1k5Ω resistor in the A7 assembly because I lost the original one as I had it desoldered to check it (it was perfectly fine, and the 1 5 2 bands screamed so at me; who failed to listen); now probably a few of the adjustments need redoing.

That was not a very brilliant rabbit hole to descend in. 

Anyway, you only get a counter to do this precise counting off of a FeelTech if you lock it to the FG second output. Neat trick. My 1MHz might not be the same as your 1MHz, but it's mine, and same everywhere here!



There's one flaky Nixie, but it works sometimes: (at 10s timing mode, so overflowed)



Happy. Next step is to adjust input gain. Are the card edge connectors unobtainium? A lot of work is impossible unless cards are on extenders...

[tautech]

What else did I miss overnight....Vince, although you might now hate them simple fixes on flat screen anythings can be money for jam. That was at one time mnem's MO, grabbing anything that might be half decent from the curbside to fix and flip.

Well, this TV is worth 1650 bucks brand new, so yes I would be delighted to sell it and pocket the money ! 

But it's not mine...


Finding stuff on the curb ... there is no such thing in France. That's the problem. What used to be on the curb many years ago, now people sell on leboncoin.fr and want 50 to 100 Euros / USD  for it.
You can't get old broken electrical / electronic stuff from the dump yard because nowadays all the consumer electrical appliances are stored in a locked container with cameras watching you. Strictly forbidden to grab stuff that others have brought in. Silly, but that's how it is.

There is no source of cheap broken stuff to fix (or just salvage parts from), that's the big problem here....

Yep at one time we had annual inorganic recycling collections where everyone just left their junk on the roadside outside their house.......it turned into the biggest swap meet you ever did see with ppls driving around stuffing their cars full of stuff they thought they could fix and if something they spied looked better something they had already collared got dumped off to fit their new find in ! 
It was pure bloody mayhem for a week or so before the trucks came to take the ever growing piles away and it just couldn't go on so now we must book our collection some months before they do our area and our pile must be inside our properties and be 1m³ max !

There you go again.....authorities stealing all our fun ! 

Just trying to decide if Philips or HP stuff will be in the collection next time ! 

[mansaxel]

What is the serial number of your 5245L?

It's a 1221G prefix unit (Made in Germany). I have the paper manual for 716- which clearly isn't adequate. I have 628- since before as PDF, and Keysight offers 1124A- as their usual "couldn't care less" bad PDF. But it is enough to read out the test voltages from. Which is good. 

[Cerebus]

- A very strange key for electrical cabinets. Three of it's four sides are like nothing that I've ever seen. Usage for electrical cabinets is stated by former owner.

Now I have definitely seen one of those before, but I can't remember quite where. I'll ponder it...

[tggzzz]

I had a summer job at university stuffing boards with one of those bloody things . I lasted about a week before they promoted me much to the disgust of people who had been doing it for 30 years.

Presumably you were sufficiently incompetent at board stuffing.

I was told I was affecting team morale. I learned a lot about politics and competence in those 6 weeks.

Bringing people to the understanding that they aren't doing things as well as others can is a traditional problem. The only work around is to only hire people that will automatically and enthusiastically adopt best practices.

Recruiting such people requires skill and (in the short term) courage.

[Neomys Sapiens]

- A very strange key for electrical cabinets. Three of it's four sides are like nothing that I've ever seen. Usage for electrical cabinets is stated by former owner.

Now I have definitely seen one of those before, but I can't remember quite where. I'll ponder it...

I hope much that you can recall it. I would be very interested in this information!

[vk6zgo]

Transformerless radios, etc were all but unknown in Oz back in the day.

Not to forget that all valve TV sets and many early transistorised TV sets made in continental Europe were transformerless. All the German P...-valves were developed for this purpose.

It all seems like a lot of effort to avoid using transformers, which aren't that heavy, or costly.
OK, some places in many countries still had DC mains, but it seems silly to force the majority to cater to the needs of a minority.

All Oz TV sets, bar the little Admiral "portable" of the early 1960s used power transformers, up until the advent of colour, when SMPS
took over.
Even the "Ekco" TV sets which sold for a few years in the the late '50s, early '60s were re-engineered to Oz style.

Those few places with DC mains used vibrator type Inverters, which came in many flavours from 32vDC/240v ac for farm lighting plants, through 110vDC/240vac, to 230v DC/240v ac.

AWA fielded the first generation of Solid State Inverters, but their own TV sets didn't like the near square wave they supplied, & many were replaced with the "archaic" vibrator type.

Strangely, Sony did sell some series heater BW TV sets in the early 1970s. 
They used the basic design used in the US market, but included a 240:120 volt transformer, making it a "cold" chassis set.

They were crappy sets, initially, as the plastic Sony used for the deflection yoke broke down under high voltage & high frequency content of the line deflection signals.
Later, they changed the material, but the end had come for valve designs, & the next model was solid state, with a more conventinal power transformer.

[mnementh]

   - A very strange key for electrical cabinets. Three of it's four sides are like nothing that I've ever seen. Usage for electrical cabinets is stated by former owner.

Now I have definitely seen one of those before, but I can't remember quite where. I'll ponder it...

Looks a lot like one grandmomma kept for her mantle clocks.

mnem
 

[vk6zgo]

I had a summer job at university stuffing boards with one of those bloody things . I lasted about a week before they promoted me much to the disgust of people who had been doing it for 30 years.

Presumably you were sufficiently incompetent at board stuffing.

I was told I was affecting team morale. I learned a lot about politics and competence in those 6 weeks.

Translation = Get that little smart arse outta here !

What else did I miss overnight....Vince, although you might now hate them simple fixes on flat screen anythings can be money for jam. That was at one time mnem's MO, grabbing anything that might be half decent from the curbside to fix and flip.

I was an old smartarse!

It was hard not to call out the many Management driven stuffups & inefficiencies rampant at one place I worked, so I became, effectively, "an enemy of the people".
Fortunately, they didn't have a Gulag handy, so I was "let go".

They were useless at that, too, so asked me to stay on till they could replace me, & promptly forgot they had sacked me!
I needed the money, so staggered on for another year or so, then "pulled the plug"---this time, giving them a hard finishing date.

[mnementh]

My current distraction... 

mnem
Caffeine levels dangerously low... must stop for refill...   

   3D Web Viewer

Currently printing. Lots of print & trial fit fettling with the model to get the body so it fits the socket in the scope properly.

mnem
I do hope this is the last iteration...