Test Equipment Anonymous (TEA) group therapy thread

[grizewald]

My offer to show how I re-capped an hp 5248L PSU back in August 2020 has generated an interest and a request for pictures on how I did it. So I pulled out the counter this morning and took some new pictures. <snip>

I love the way these old classics were put together. One PCB for each sub-circuit and everything put together with enough metalwork to ensure that it would last not just one, but several lifetimes.
From the look of it, I can imagine that its weight is considerable.

Thanks for the pictures!

[med6753]

My offer to show how I re-capped an hp 5248L PSU back in August 2020 has generated an interest and a request for pictures on how I did it. So I pulled out the counter this morning and took some new pictures. <snip>

I love the way these old classics were put together. One PCB for each sub-circuit and everything put together with enough metalwork to ensure that it would last not just one, but several lifetimes.
From the look of it, I can imagine that its weight is considerable.

Thanks for the pictures!

Damn thing is almost as heavy as a 500 series.

[mansaxel]

From the look of it, I can imagine that its weight is considerable.

Proper enheavyment in every detail, indeed. I'd guess at ~20 kilos, and well balanced, i.e. heavy both front and back. The gorgeous handles on the front and sides make handling pretty unproblematic still.

[grizewald]

TV REPAIR

OK I knew it was too good to be true, it was going too well, I should have been wary....

Just started buttoning it back up. Screwed the two metal brackets that hold the plastic feet, back onto the chassis.
Re-installed the speakers.

Quick check to see if I can get sound from it.

TV is entirely controlled via the IR remote, there are no buttons on the TV itself.
Guess what ? Yes, the fucking remote doesn't work, can't operate the TV !!!

Batteries are good. Pointed the IR LED to my camera and I can see bright light coming out of it when I press buttons, so the remote works.

Yet the TV does not respond at all !

Yes, the ribbon cable connecting the IR receiver to the digital board, is plugged in properly, but no joy.

So that means I did all that work for nothing and I will probably not even get back the 14 Euros I spent to buy the new LED strips !

That's why I hate consumer stuff... I just hate it with a passion !!! 

Maybe you just nudged the receiver out of place when you reassembled it?

Of course, this means you'll have to take it apart again and for that, you have my pity.

[Vince]

No I didn't disturb the receiver, I left it in place, it's mounted on the front bezel so I left it there when I dismantled the TV.

I have not yet put the rear cover back on, luckily, so I still have access to the boards / cables, I could troubleshoot it... if I could be arsed, but I am fed up with this thing.... 

[med6753]

After 1 hour the beast is dead nuts. But I don't know how much longer I can listen to that fucking fan. 

[grizewald]

No I didn't disturb the receiver, I left it in place, it's mounted on the front bezel so I left it there when I dismantled the TV.

I have not yet put the rear cover back on, luckily, so I still have access to the boards / cables, I could troubleshoot it... if I could be arsed, but I am fed up with this thing.... 

Just a wild guess, but are the screws for the metal brackets that hold the feet on, the correct screws? Wouldn't be the first time a cable has been cut with too long screws...

[bd139]

After 1 hour the beast is dead nuts. But I don't know how much longer I can listen to that fucking fan. 

This neatly explains why I don't own some of the older boat anchors 

The 5328A is pretty fucking noisy. Going further back in time isn't going to be better.

[med6753]

After 1 hour the beast is dead nuts. But I don't know how much longer I can listen to that fucking fan. 

This neatly explains why I don't own some of the older boat anchors 

The 5328A is pretty fucking noisy. Going further back in time isn't going to be better.

I've heard that there isn't a suitable substitute fan that would provide the required airflow/cooling so you have to live with it or shut it off.....which I'm about to do. 

[Vince]

No I didn't disturb the receiver, I left it in place, it's mounted on the front bezel so I left it there when I dismantled the TV.

I have not yet put the rear cover back on, luckily, so I still have access to the boards / cables, I could troubleshoot it... if I could be arsed, but I am fed up with this thing.... 

Just a wild guess, but are the screws for the metal brackets that hold the feet on, the correct screws? Wouldn't be the first time a cable has been cut with too long screws...

Nah, those feet are miles away from the receiver, or any electronics or cables.  See pic below. Circled the meal brackets in red, and in green the receiver and its cable going to the connector on the digital board.

[Vince]

After 1 hour the beast is dead nuts. But I don't know how much longer I can listen to that fucking fan. 

Not to worry Papa Smurf. As age is coming and hearing is going south, soon you won't notice that HP fan more than you notice the compressor in your fridge today -->  problem solved ! 

[mnementh]

No I didn't disturb the receiver, I left it in place, it's mounted on the front bezel so I left it there when I dismantled the TV.

I have not yet put the rear cover back on, luckily, so I still have access to the boards / cables, I could troubleshoot it... if I could be arsed, but I am fed up with this thing.... 

Just a wild guess, but are the screws for the metal brackets that hold the feet on, the correct screws? Wouldn't be the first time a cable has been cut with too long screws...

Nah, those feet are miles away from the receiver, or any electronics or cables.  See pic below. Circled the meal brackets in red, and in green the receiver and its cable going to the connector on the digital board.

Didja maybe plug the ribbon in flipped upside-down? 

Also, sometimes the contact traces will break loose and fold over so one or more doesn't make contact anymore... check for that too.

mnem
Ask how viscerally I know that shame... 

[med6753]

After 1 hour the beast is dead nuts. But I don't know how much longer I can listen to that fucking fan. 

Not to worry Papa Smurf. As age is coming and hearing is going south, soon you won't notice that HP fan more than you notice the compressor in your fridge today -->  problem solved ! 

I'm already half deaf in my right ear and it's still too loud. 

[david77]

If you can't trust HP to supply a quality C5 lead, then how can you trust any other supplier, IMO they are cheap crap for throw-away consumer tat.

David

I have never had one fail on me or cause a dangerous situation. Neither, granted, have I had a PH163 fail or hurt me, but that's because I always treat them as the Princess and the Pea, with utmost care, always connect the appliance end before the wall plug and so on.  No such niceties needed with the C5/C6 combos; they're sturdy, safe and reliable.  Further, the scarcity of PH163 leads would no doubt tempt people to use them even when damaged, thereby increasing risks.

I've had a C5 lead fail on me once. Order a new PSU brick for my Thinkpad, plugged it in and with a loud bang and sparks out of the Schuko plug the lights went off.
Of course it was the middle of the night so I had to feel my way to the fusebox and reset the breaker.

Afterwards I inspected the lead and the supply. The lead was a crappy chinese made on with maybe two strands of copper steel wire used per wire. Maybe good for 100-200mA? And there was obviously a short inside the molded plug.
I checked the PSU too and realised that that was also a knock off of the real thing. Needles to say I threw the PSU straight in the bin, too. Bought a used genuine Lenovo supply after that piece of shit.

But I'm happy using C5 in general. Nothing wrong with it, really.

[dl6lr]

Is it different than the numbering on the connector?

https://files.edac.net/edac/content/series/og/English/EDAC%20307%20357%20Series%20Card%20Edge%20Connectors%20English%20Ordering%20Guide.pdf

It says 1 - A, 2 - B, 3 - C and so on; skipping "G" and "I" for Reasons, one assumes...

Hmm, I assume they skip Q too, which would be pin 15 for connectors if only G and I are skipped...

Edit: According to https://www.aceamusements.us/understanding-the-jamma-pcb-and-edge-connector-pinout.html
they skip O and Q too.

[Vince]

After 1 hour the beast is dead nuts. But I don't know how much longer I can listen to that fucking fan. 

Not to worry Papa Smurf. As age is coming and hearing is going south, soon you won't notice that HP fan more than you notice the compressor in your fridge today -->  problem solved ! 

I'm already half deaf in my right ear and it's still too loud. 

You are making me reconsider my desire to get one of these old HP counters...... can't a more modern and quieter fan be fitted ? Like one of those low RPM high CFM ones, that are very thick ?

[Vince]

No I didn't disturb the receiver, I left it in place, it's mounted on the front bezel so I left it there when I dismantled the TV.

I have not yet put the rear cover back on, luckily, so I still have access to the boards / cables, I could troubleshoot it... if I could be arsed, but I am fed up with this thing.... 

Just a wild guess, but are the screws for the metal brackets that hold the feet on, the correct screws? Wouldn't be the first time a cable has been cut with too long screws...

Nah, those feet are miles away from the receiver, or any electronics or cables.  See pic below. Circled the meal brackets in red, and in green the receiver and its cable going to the connector on the digital board.

Didja maybe plug the ribbon in flipped upside-down? 

Also, sometimes the contact traces will break loose and fold over so one or more doesn't make contact anymore... check for that too.

mnem
Ask how viscerally I know that shame... 

Hmmm... lemme see... nope, connector is keyed on the digital board (didn't disturb on the receiver end). But I unplugged it and plugged it back in just in case, and for a brief moment I spotted a red LED lighting up in the receiver !! 

So I put the TV back up, tested it, no joy.... then an idea, I lifted the TV slightly with one hand from a corner, then used the remote using the other hand, and yes it works !! 
So I think the problem was simply that the receiver is not pointing forward enough, it needs  the TV to be on its feet, a bit off the bench for it to receive properly, that's all ! 

Problem solved.... immediately traded for a new problem !

As I was playing with the TV standing up, it slid on the bench and fell on it's face.

LCD survived but now the last/ fourth LED strip comes and goes, it's intermittent ! With the laying flat on its face, it works fine, but when you lift it to make it stand up, it's pot luck. Then also notive that 3 of the LEDs are now VISIBLE ! You can see 3 white dots at the bottom....
So me think during the accident that LED strip came off (that glue is crap it seems ! ), now the LED strip is a bit loose.


So... I need to dismantle the TV again, remove the bezel, the LCD screen, all the layers behind it, get back to the LED strips and fix that 

And my friend just phoned me, he will be here to pick-up the TV  at 18H30, that's in 1h45min ! So not much time to do it all !! 

I HATE TV's !!!!!!!!

[Saskia]

go for the 50 grams solution then...

[Specmaster]

go for the 50 grams solution then...

Big flash, RIP Consumer goods i.e., flat TV and Vince 

[m k]

5245L report:

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...

No, they are available here: https://www.digikey.de/de/products/detail/edac-inc/307-030-500-202/107614

Fun fact: I ordered them on 2022-03-15 and they were €4.03 each...

I tried to make my own easy extender boards but I haven't ordered them yet. Current design is connected both sides with vias (as used in the 5245L), but maybe I will isolate both sides so they can be used with full 30 pins too. Test points and holes for eyelets. Will gladly give you the KiCad project (its only drawn with the PCB editor).

Very cool.

I'd love to get the project files. Many, but not all, of the connectors are bridged (joining both sides of the connector), so I believe that isolation is a Very Good feature. I'll work a bit on my queue of JLCPCB orders and try fitting it in.

Jamma adapters are 3.96 mm spaced, or .156" but some Fluke stuff are .150" or 3.81 mm, very nice.

[Vince]

go for the 50 grams solution then...

Oh yes I wish !!!! 

I pulled the power plug : IEC socket detached from the power board !!! You just can't make this shit up ! 

OK now I have removed the LCD and have access to the LED strips and plastic diffuser.

Look at the pics..... problem is not at all what I thought it was, it's much WORSE !

The strips didn't detach / com loose, no, look... the white dots I was seeing on the bottom edge where not due to that.... It looks like the edge of the diffuser, during the impact/fall, must have contacted for a split second some of the LEDs, and the LEDs BURNED the hell out of the diffuser ! See ! The plastic has changed appearance, it liked "bubbled "or seomthing ! 

So it's not repairable, the diffuser is cooked, literally 

So I guess the best I can do now is flip the diffuser 180° so that the burned / damaged bottom edge, ends up being now the top edge... hoping that the white dots won't end up at the top now 

OK, friend is supposed to arrive in 10 minutes or so. I will show him the devastation and see what he wants to do...

[Zoli]

Is it different than the numbering on the connector?

https://files.edac.net/edac/content/series/og/English/EDAC%20307%20357%20Series%20Card%20Edge%20Connectors%20English%20Ordering%20Guide.pdf

It says 1 - A, 2 - B, 3 - C and so on; skipping "G" and "I" for Reasons, one assumes...

Hmm, I assume they skip Q too, which would be pin 15 for connectors if only G and I are skipped...

Edit: According to https://www.aceamusements.us/understanding-the-jamma-pcb-and-edge-connector-pinout.html
they skip O and Q too.

The reason for skipping some letters/numbers is the low resolution silkscreen, which make an easy confusion: I-L-1, O-Q-0, G-C, U-V; not to mention how it look after some (mis)handling...
Here's an example:

[grizewald]

As I was playing with the TV standing up, it slid on the bench and fell on it's face.

I get the impression that the TV hates you just as much as you hate them!

[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:

You're not blind! It's where you download the MSDS from which makes the difference. In some countries, the manufacturer does not need to detail every chemical used in a product and can hide these chemicals as "trade secrets" or under generic terms. Often, it is the relative volume of a chemical which determines whether it must be listed in a MSDS or not. Have a look at the two attached MSDS for the Loctite "SF 7452" accelerator. In the US version, they list the composition as "acetone and fragrance". In the other MSDS for the same product, but for a market with more stringent disclosure laws, the composition is listed as "acetone and N,N-Dimethyl-p-toluidine". Listing N,N-Dimethyl-p-toluidine as "fragrance" is comical! Fragrance in acetone? 

To start the process of polymerisation in cyanoacrylates, the presence of a slightly basic or nucleophilic compound is required, most commonly water. However, in the cases where the thickness of the CA layer prevents water from gaining access past the surface of the initial polymerisation, or where the surfaces to be bonded are acidic in nature, an accelerator is needed. Acetone is neither basic or nucleophilic and therefore cannot have the properties that an accelerator needs. What it does have is the ability to evaporate quickly which is why it is used as a solvent for the actual accelerator. So when you apply the accelerator, the solvent (acetone, hexane or similar) delivers the accelerator to the areas to be bonded and then rapidly evaporates, leaving the accelerator behind, nicely distributed over the areas and ready to do its job.

If you want to get a better understanding of cyanoacrylate chemistry, here's a document which will help: https://scitechconnect.elsevier.com/wp-content/uploads/2014/07/Reactive-Polymers-Fundamentals-chap13.pdf

Lesson learned; the MSDS doesn't list ALL the active ingredients; you have better chance with TDS to find all the ingredients. But anyway, my interest in organic chemistry topped up around the C-3/C-41/E-6 level...

[bd139]

go for the 50 grams solution then...

Big flash, RIP Consumer goods i.e., flat TV and Vince 

Made me think of this for some reason



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