Test Equipment Anonymous (TEA) group therapy thread

[Neomys Sapiens]

Is there possibly a military grade high resolution video system with small screens?
Just wondering from where HP got their idea.

A cursory look at my records turned up the following ducuments:

RCC 452-86 Video standards and Formats (RCC: Range Commanders Council)
MIL-HDBK-87213A (USAF) ELECTRONICALLY / OPTICALLY GENERATED AIRBORNE DISPLAYS
MIL-STD-1556 Aircrew station displays and assoc. equipment, definitons of

Will take another look later.

[Zoli]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

[bd139]

This sounds like the comedic "talk-ins" you get on 2m at hamfests. I actually used to drag my FT818 along just so I could listen to them getting lost and angry

The most´hilarious samples of this type were available when big events or massive situations did lead to units from distant parts of the country being deployed to the region and being present on the radio net in the former times of analogue BOS radio (our PSB).

Episode 1.) Our twin city across the Rhine (situated in the federal state of Rheinland-Palatinate) Ludwigshafen is a city with a very high concentration of chemical industry. A major local event is the annual SAP Marathon, which is often routed through both cities and states. One of the companies which reside in Ludwigshafen is called Raschig. It exudes the smell of road marking paint multiplied hundredfold most of the time and sometimes even more.

Conversation on the combined inter-agency event special channel coming suddenly up during an otherwise dull waiting period:
<Marathon Lu 7-63 : a team of Paramedics or Firefighters from a remote, rural part of Rheinland-Palatinate, tasked with providing a first-aid post and close off a large intersection>:
(very agitated and partially scrambled) 'Marathon Lu from Marathon Lu 7-63!! You must stop, we must abort! Here was an industrial accident! It stinks and we do feel dizzy. What should we do? Send us help.. It smells so much. This must be dangerous'
'Marathon unit calling in Marathon Lu, please state your position!'
'Here is Marathon Lu 7-63..We are where the industrial accident is!'
'Marathon Lu 7-63 for Marathon Lu, what is you assigned position?'
'Here is Marathon Lu 7-63, we do not know. IT STINKS!'
'Marathon Lu 7-63, stand by!'
(here you could hear the conversation in the coordination center)
'Give me the list..lets see---7-63?!?'
(silence of a minute)
Parallel, regular police channel of Ludwigshafen:
'Ludwig 1107 <patrol car native to the area> for Ludwig <dispatch>?'
'Here's 1107 - what gives?'
'Do you know how the Raschig smells when it stinks normally?'
'Yes - so?'
'Ok, please proceed to the intersection Road A/Road B (which is behind the Raschig factory). There are some comrades from X-town at a marathon post - they believe that there was an accident at the factory because of the smell!'
(sound snippets of roaring laughter from various stations and units)
'Ludwig for 1107, we will continue our patrol. We passed by there earlier. Raschig smells since yesterday - somewhat, but not much!>

Episode 2.) During the violent Kurdish mass protests in the 90s, police units from the whole of Germany were deployed to Mannheim. One such unit apparently got lost:
'Cavalier <Pol. Ma foreign contigents directions and assignments> for Hanno 400 <unit of riot police from Hannover>, where are we here? We do not know where we are! Where should we go?>
'Hanno 400, can you describe your position?'
'Cavalier, there is a large building, looks like some company, and another one on the other side. And a parking lot...with a fence. And another, without a fence..'
(this description applies to several 100s or even 1000s of places in our metropolitan region, so it is useless)
'Hanno 400, can you see any conspicious landmarks?'
'We can see some hills in the distance, but they are not close'
(again not helpful, as this applies to 3 of the 4 cardinal directions here)
'Hanno 400, have you tried asking for directions to Point X?'
'Yes. The driver said that we should call the police - but we are the police!'
'Are you sure? (continuing in a pronounced dialect of SW Germany) Dohin wees die Bollizei wo se rumfaehrt! ('here the police knows where it drives around!''

That’s hilarious  . Thanks for taking the time to write it up.

[bd139]

Have you tried FreeCAD?   

This is quite funny. I was having a discussion yesterday with a colleague about software. He got into 3DP recently and tried to use FreeCAD for about a month before giving up. His comment was that it should be put into a skip with LibreOffice, Thunderbird, Gimp and Darktable. Having, through no irony at all, used all of them I had to agree. He uses a mac now as well to quote because “his tears were burning the cuts on his arms after a year on Ubuntu” 

[bd139]

Find an image editing tool with white balance control on it. Click that then click the bit of the picture they’ll at is supposed to be white. Job done. 99% of the photo is the photographer not the camera

med uses Winbloze. Windoze Photos works very well for minor post-processing; that pic, I'd just turn the "WARMTH" and "CLARITY" sliders up a click or three; would make a world of difference. Vince complains about my grey printed knobs being purple too; personally, I suspect the monitor he's using injects a wee bit of bloo.

mnem
 

 

No I don't. IrfanView64.

I am sorry for your loss 

[Robert763]

TV REPAIR

Make sure if you are able to resurrect the other strings, that your friend is well aware that he might actually spot areas of his screen that are dimmer than others, in the areas with the dead LEDs, otherwise he might not be happy with you. Short of replacing all the strings, I can see no way around that problem. Great work so far, keep it coming.

Well yes if I manage to fix the thing I will see if the lighting is even enough to be acceptable, i fnot will tell him what he wants to do.

Hopefully there WILL be dark spots and he will tell me OK fuck you can keep it... more spare boards/parts for Vince ! 

We shall see.

I don't know where to buy the strings nor how much that costs. If it's available for this particular TV, and is ridiculously cheap including shipping... like 20 Euros shipped, and given the TV is recent, maybe he will want to pay for that. We are not there yet....

Why the eff would you trash an obviously repairable TV like that? Just put it away and wait for a paycheck so you can buy some LEDs for Ifni's sake. You really should replace those LEDs anyways, even if you are sending it back to the owner. Just jumpering them out is begging for all the others in the string to fail prematurely.

Correct repair, short of replacing them all, would be to measure voltage drop across every LED with them lit up and replace any that read appreciably lower or higher than the average. That would be your best chance to avoid recidivism. You already have a cheap hot-air rework station, right?

mnem
 

These LEDs are driven by an active constant current source. Shorting out one or two does not stress the other LEDs in the string. It does affect the CC driver but probably not enough to reduce it's reliability.

[Specmaster]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

I've just checked my bench meters and was pleasantly surprised to discover that my oldest meter, HP 3466A also gave me the highest voltage in diode mode of 4.6V and handhelds only giving me 3.2V, one more reason for keeping the HP then 

[med6753]

Find an image editing tool with white balance control on it. Click that then click the bit of the picture they’ll at is supposed to be white. Job done. 99% of the photo is the photographer not the camera

med uses Winbloze. Windoze Photos works very well for minor post-processing; that pic, I'd just turn the "WARMTH" and "CLARITY" sliders up a click or three; would make a world of difference. Vince complains about my grey printed knobs being purple too; personally, I suspect the monitor he's using injects a wee bit of bloo.

mnem
 

 

No I don't. IrfanView64.

I am sorry for your loss 

Gee....seems to work OK for my needs. 

[Robert763]

On solder, I have a Really Useful Box full of reels. One of the shallow 4 or 5 litre boxes. So I think I'm got enough to see me out. 

[bd139]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

I've just checked my bench meters and was pleasantly surprised to discover that my oldest meter, HP 3466A also gave me the highest voltage in diode mode of 4.6V and handhelds only giving me 3.2V, one more reason for keeping the HP then 

Yeah I measured the 3465A. It doesn’t have a diode mode. You stick it in 1K ohms and it works. 4.6V too. Same circuit probably.

[med6753]

Next project. 465B PSU re-cap. Just like the 475A done a few weeks ago the Trigger board has to come out for access to the capacitors. And just like the 475A it's all modular except for two soldered wires so removal is easy and painless.



The capacitors exposed. Only 5 cans vs 6 cans in the 475A. Reference voltage is different too. +55V for the 465B vs +50V for the 475A.



I went back and looked at the repair history on this 465B and it has a checkered past. I replaced ALL the tants on the Vertical board as well as a few key ones on the main board. The CRT had to be replaced since it had poor focus.

Won't be able to pick up again on this project until early next week.

[bd139]

Good write up as always 

Might have to refurb this 465B yet. Still waiting for that IC to turn up.  Hopefully today. If it checks out I’ll do a full clean and cal on it and sorted.

[Vince]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

Thanks, I do have a Fkuke 8060A !!! 

It's buried in storage currently, can't dig it out, too much work, but I will keep that in mind 

[Vince]

TV REPAIR

Make sure if you are able to resurrect the other strings, that your friend is well aware that he might actually spot areas of his screen that are dimmer than others, in the areas with the dead LEDs, otherwise he might not be happy with you. Short of replacing all the strings, I can see no way around that problem. Great work so far, keep it coming.

Well yes if I manage to fix the thing I will see if the lighting is even enough to be acceptable, i fnot will tell him what he wants to do.

Hopefully there WILL be dark spots and he will tell me OK fuck you can keep it... more spare boards/parts for Vince ! 

We shall see.

I don't know where to buy the strings nor how much that costs. If it's available for this particular TV, and is ridiculously cheap including shipping... like 20 Euros shipped, and given the TV is recent, maybe he will want to pay for that. We are not there yet....

Why the eff would you trash an obviously repairable TV like that? Just put it away and wait for a paycheck so you can buy some LEDs for Ifni's sake. You really should replace those LEDs anyways, even if you are sending it back to the owner. Just jumpering them out is begging for all the others in the string to fail prematurely.

Correct repair, short of replacing them all, would be to measure voltage drop across every LED with them lit up and replace any that read appreciably lower or higher than the average. That would be your best chance to avoid recidivism. You already have a cheap hot-air rework station, right?

mnem
 

These LEDs are driven by an active constant current source. Shorting out one or two does not stress the other LEDs in the string. It does affect the CC driver but probably not enough to reduce it's reliability.

Yes and no. There are 4 strings but the driver has only two outputs, so they wired strings in 2 parallel pairs : string 1 and 2, and strings 3 and 4.  So the chip can only regulate the overall current in a pair but has no clue about how the current splits between the two strings in a given pair. So if you remove one LED then there is an imbalance that the chip can't know about nor act upon.
I assume that's what Dragon had in miind...

In my case I am "lucky" in that I have one failed/bridged LED in each string of a pair, so they still have the same number of LEDs each !!! 

[Specmaster]

Currently, sitting here waiting for the workmen to arrive. We are having the bathroom refitted and were told that they would be with us this morning at 8.00AM, now 8.54AM and still sign of them. The job is supposed to take upto 2 weeks, thinking of taking friendly bets on the completion date 

[Atomillo]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

I've just checked my bench meters and was pleasantly surprised to discover that my oldest meter, HP 3466A also gave me the highest voltage in diode mode of 4.6V and handhelds only giving me 3.2V, one more reason for keeping the HP then 

Does anyone really need any reason at all to keep old HP gear?? 

[AVGresponding]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

I've just checked my bench meters and was pleasantly surprised to discover that my oldest meter, HP 3466A also gave me the highest voltage in diode mode of 4.6V and handhelds only giving me 3.2V, one more reason for keeping the HP then 

Yeah I measured the 3465A. It doesn’t have a diode mode. You stick it in 1K ohms and it works. 4.6V too. Same circuit probably.

The O/C voltage can be misleading; none of the mentioned meters will measure as far as that I'll bet. Vince likes his Metrix MX-series, and they have an O/CV of ~4, but won't give a reading on a white LED, despite making it light. The forward voltage of this diode is 2.7V according to my Fluke 289, which has an O/CV of 5.4 but will for sure not measure above 3V or so, and the same applies to the Fluke 89 V which has an O/CV of 7.3, and will light two 2.7V white LEDs in series, but will not give a reading.

[Specmaster]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

I've just checked my bench meters and was pleasantly surprised to discover that my oldest meter, HP 3466A also gave me the highest voltage in diode mode of 4.6V and handhelds only giving me 3.2V, one more reason for keeping the HP then 

Does anyone really need any reason at all to keep old HP gear?? 

Not really but then it is only a 4.5 digit meter when my others are either 5.5 or 6.5 and its the only one that does not have safety shrouded leads.

[Specmaster]

A quick update on the current state of politics in the UK, you have been warned  News flash on BBC, the PM is going to resign today and is expected to remain in post until the autumn. End of news flash, normal service will resume now 

[Cerebus]

Condolences then. I'd rather drill screws through my feet than ever use that fustercluck again. Only app I ever found less intuitive than EagleCAD. 

mnem
*cringe*

Ah, so you've never used FreeCAD then? 

[vk6zgo]

...
As for DMM's, I don't have fancy modern ones that can test white LEDs.
...

You don't need a new and fancy DMM to test the LED's; as example, my DMM870(1998) gives 3.2v,  and the 8060A gives 8V in diode testing mode, both enough to light up any LED's.
That's why I've asked to check your multi-meters, so next time you will know which is suitable for LED testing(is part of "Know your tools" training) 

That's "new & fancy" to me!
My Fluke 77 won't turn on blue LEDs, either, as they also require 3.2v.

My "bodge tester", consisting of a 9v battery, a 360 resistor, a switch, and a small "junk" pin connector does, though!
(I dunno how I happened to have 360 resistors & not 330 , but that's what my junk box had!)

An old ADSL box teardown yielded some nice blue LEDs with long leads, plus two bicolour ones.(red & blue, so if I ever need  a purple light, I'm in good shape!)

[tggzzz]

End of an era. I've had that same roll of 60/40 for perhaps 40 years.

Mine is ~38 years old. Can't be more than 36.

[med6753]

Good write up as always 

Might have to refurb this 465B yet. Still waiting for that IC to turn up.  Hopefully today. If it checks out I’ll do a full clean and cal on it and sorted.

I didn't know yours had a bad IC. That must of happen when I was on vacation. I have a 465B parts mule and I would have given you the IC for cost of shipping only.

[bd139]

Good write up as always 

Might have to refurb this 465B yet. Still waiting for that IC to turn up.  Hopefully today. If it checks out I’ll do a full clean and cal on it and sorted.

I didn't know yours had a bad IC. That must of happen when I was on vacation. I have a 465B parts mule and I would have given you the IC for cost of shipping only.

Yeah was a few days back. Details here:

discovery: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4268857/#msg4268857

workaround: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4268941/#msg4268941

first power up: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4268986/#msg4268986

Dang it  . Paid £23 for a replacement NOS part here 

[Cerebus]

One fervently hopes that those LEDs are driven by an active constant current source. Shorting out one or two does not stress the other LEDs in the string. It does affect the CC driver but probably not enough to reduce it's reliability.

FTFY

Relying on someone doing things the way they should have been done can be foolhardy.