Test Equipment Anonymous (TEA) group therapy thread

[Mortymore]

...Or just have fun getting into it as deep as your practicle knowledge and requirements allow.
Have fun, Frans

That's my philosophy on the subject.
In the beginning of times... bought some old DMM Fluke's on Evelbay, not the latest models that needs accurate parameters to be stored in a memory, but those old school that can be calibrated by adjusting 1 to 3 pots and 1 or 2 caps. Then fetched some samples from Texas or Maxim, and build my own reference boards.

[bd139]

That was a labour of love madao! Were all those capacitors really bad?

All capacitor leaks their eletrolytics, common failure of early SMD eletrolytics.

Believe it or not I came face-to-face with someone here on the blog who questioned how we came to do mass capacitor replacements and considered it "uneducated" troubleshooting.   

Even sighting examples such as vacuum tube equipment with wax caps and dry electrolytics, 1970 - 1980's vintage beaded tants, etc did not convince him otherwise. 

If we apply it to the human body then it doesn’t look like quite as good a diagnostic process.

Really only some capacitors get replaced on sight for me. Usually only RIFAs which are cracked. I have 40+ year old electrolytics still absolutely fine. High ESR is an almost perfect indicator of problems and it’s measurable in circuit. The reason stuff tends to get shotgunned is lack of equipment. Best bet is really to:

1. Visible inspection.
2. ESR measurement.
3. Replace anything leaking, high ESR or RIFA.
4. Power up, leave for an hour. Or replace any shorted tants when this doesn’t work.
5. Have a feel around for warm ones and replace them.

The main issue with shotgunning is cost. Secondly risk of screwing up the device entirely. You’ve all seen it, particularly that 475 I picked up at Newbury last year

[McBryce]

Anxiety is another reason. In the Amiga community for example, the A600 and A1200 used some of the earliest SMD electrolytics and they leak often. The user doesn't open his/her computer regularly to check their state and by the time the problem becomes externally noticeable (fails to boot), quite often the damage to the PCB is already considerable, so they tend to replace all caps as a matter of damage avoidance.

McBryce.

[bd139]

Indeed. Those are probably replace on sight these days (not by twisting  )

Still my favourite video in recent years. RIFA in action:

[McBryce]

The guys at Acorn had the foresight to include a small grill directly above the area so that the RIFA can let the smoke out


McBryce.

[Specmaster]

Indeed. Those are probably replace on sight these days (not by twisting  )

Still my favourite video in recent years. RIFA in action:

That one was fairly quiet when it let go, so glad we don't have smell internet technology yet 

[madao]

That was a labour of love madao! Were all those capacitors really bad?

All capacitor leaks their eletrolytics, common failure of early SMD eletrolytics.

Believe it or not I came face-to-face with someone here on the blog who questioned how we came to do mass capacitor replacements and considered it "uneducated" troubleshooting.   

Even sighting examples such as vacuum tube equipment with wax caps and dry electrolytics, 1970 - 1980's vintage beaded tants, etc did not convince him otherwise. 

If we apply it to the human body then it doesn’t look like quite as good a diagnostic process.

Really only some capacitors get replaced on sight for me. Usually only RIFAs which are cracked. I have 40+ year old electrolytics still absolutely fine. High ESR is an almost perfect indicator of problems and it’s measurable in circuit. The reason stuff tends to get shotgunned is lack of equipment. Best bet is really to:

1. Visible inspection.
2. ESR measurement.
3. Replace anything leaking, high ESR or RIFA.
4. Power up, leave for an hour. Or replace any shorted tants when this doesn’t work.
5. Have a feel around for warm ones and replace them.

The main issue with shotgunning is cost. Secondly risk of screwing up the device entirely. You’ve all seen it, particularly that 475 I picked up at Newbury last year

Over 90% solder joint of  SMD eletrolytics has  dull / non glittering solder joint.  This is a alarm sign.

[med6753]

  The CA plug-in went from Jersey City to Springfield, Masshole and as of this morning is still sitting there. Why the hell didn't it go to the Albany, NY distribution center? Freaking USPS. It was making good progress until now. Idiots. 

[med6753]

That was a labour of love madao! Were all those capacitors really bad?

All capacitor leaks their eletrolytics, common failure of early SMD eletrolytics.

Believe it or not I came face-to-face with someone here on the blog who questioned how we came to do mass capacitor replacements and considered it "uneducated" troubleshooting.   

Even sighting examples such as vacuum tube equipment with wax caps and dry electrolytics, 1970 - 1980's vintage beaded tants, etc did not convince him otherwise. 

If we apply it to the human body then it doesn’t look like quite as good a diagnostic process.

Really only some capacitors get replaced on sight for me. Usually only RIFAs which are cracked. I have 40+ year old electrolytics still absolutely fine. High ESR is an almost perfect indicator of problems and it’s measurable in circuit. The reason stuff tends to get shotgunned is lack of equipment. Best bet is really to:

1. Visible inspection.
2. ESR measurement.
3. Replace anything leaking, high ESR or RIFA.
4. Power up, leave for an hour. Or replace any shorted tants when this doesn’t work.
5. Have a feel around for warm ones and replace them.

The main issue with shotgunning is cost. Secondly risk of screwing up the device entirely. You’ve all seen it, particularly that 475 I picked up at Newbury last year

Agreed. But in certain cases it's worth the effort to shotgun because you'll just be chasing your tail afterwards.

I cite 2 examples......old vacuum tube stuff and obviously 1990's era SMT tants.

[kj7e]

I went full MedSmerf.  But now its done.

[Specmaster]

@med Could be worse, at least its moving, unlike my Vellemen K7105, it never completed its 10 mile trip from collection point to sorting hub 

[med6753]

Looks great but I'm not a fan of Rustoleum because it takes too damn long for it to dry.

[Cerebus]

Believe it or not I came face-to-face with someone here on the blog who questioned how we came to do mass capacitor replacements and considered it "uneducated" troubleshooting.   

Even sighting examples such as vacuum tube equipment with wax caps and dry electrolytics, 1970 - 1980's vintage beaded tants, etc did not convince him otherwise. 

I think of it more like planned replacement of lightbulbs in a factory or office. You know that at some point a light is going to fail. You know something about their design life and failure rates. If you have to get a maintenance worker out for every failure you're going to spend a lot of man/woman/thing^* power on it. So instead you follow one of two strategies, you either (1) wait for a single failure and replace all the lamps on that corridor/whatever at once, or (2) replace all the lamps on a corridor/whatever on a planned replacement schedule before any of them fail.

In the case of failed lightbulbs it's merely inconvenient when one blows, or at worst involves a minor increase in risk for safety related purposes. When an electrolytic cap fails badly it can seriously damage other components or boards and, non-trivially, isn't as easy to diagnose as a blown light bulb. The increased costs of failure would therefore argue strongly for following the same strategies as used for light bulb replacement/maintenance, i.e. When the first cap starts to fail replace all similar caps, or replace all caps on a planned schedule before they fail.

Where the "planned replacement before failure for caps" falls down is that we often don't have adequate data to guide us on what would be a sensible replacement schedule. It would be nice if the service manuals had design life data included with the BOMs but in an age where a decent schematic in a service manual is a true rarity I might as well ask for the moon on a stick and a pony as well.

^* The 'thing' in question is that shambling heap in overalls we've all seen in one factory or another where you wouldn't even want to hazard a guess at the species involved, let alone gender.

[med6753]

Believe it or not I came face-to-face with someone here on the blog who questioned how we came to do mass capacitor replacements and considered it "uneducated" troubleshooting.   

Even sighting examples such as vacuum tube equipment with wax caps and dry electrolytics, 1970 - 1980's vintage beaded tants, etc did not convince him otherwise. 

I think of it more like planned replacement of lightbulbs in a factory or office. You know that at some point a light is going to fail. You know something about their design life and failure rates. If you have to get a maintenance worker out for every failure you're going to spend a lot of man/woman/thing^* power on it. So instead you follow one of two strategies, you either (1) wait for a single failure and replace all the lamps on that corridor/whatever at once, or (2) replace all the lamps on a corridor/whatever on a planned replacement schedule before any of them fail.

In the case of failed lightbulbs it's merely inconvenient when one blows, or at worst involves a minor increase in risk for safety related purposes. When an electrolytic cap fails badly it can seriously damage other components or boards and, non-trivially, isn't as easy to diagnose as a blown light bulb. The increased costs of failure would therefore argue strongly for following the same strategies as used for light bulb replacement/maintenance, i.e. When the first cap starts to fail replace all similar caps, or replace all caps on a planned schedule before they fail.

Where the "planned replacement before failure for caps" falls down is that we often don't have adequate data to guide us on what would be a sensible replacement schedule. It would be nice if the service manuals had design life data included with the BOMs but in an age where a decent schematic in a service manual is a true rarity I might as well ask for the moon on a stick and a pony as well.

^* The 'thing' in question is that shambling heap in overalls we've all seen in one factory or another where you wouldn't even want to hazard a guess at the species involved, let alone gender.

And let experience be your guide. Citing vacuum tube stuff again. Old Tek's, you are generally good to go. You'll get an odd fail here and there. Old Heathkits? Forget it. Nuke them all.

[bd139]

US heathkits are likely to blow up less on you than ours are. Daystrom, UK's Heathkit distributor, cheaped out with TCC and plessey caps which are a nightmare.

I have a few Mallory and Sprague caps here. Date code around 1959. Still test good. Only downside is they are bloody huge compared to their modern counterparts.

[med6753]

US heathkits are likely to blow up less on you than ours are. Daystrom, UK's Heathkit distributor, cheaped out with TCC and plessey caps which are a nightmare.

I have a few Mallory and Sprague caps here. Date code around 1959. Still test good. Only downside is they are bloody huge compared to their modern counterparts.

Yep, Mallory and Sprague are top notch which is why Tek used them. 

[tggzzz]

Category: Simple but useful

3D printed pointer for pics -

(Attachment Link)

That's a cool idea. Must make one.

Personally I'd remember KISS, and cut a piece of paper/card to the right size and shape.

[med6753]

Gee, I'm sitting here wondering why I feel chilly. Forgot to turn the thermostat up. D'OH.

In the meantime I'll fire up the 535A for a quick burst of warmth. 

[BU508A]

Gee, I'm sitting here wondering why I feel chilly. Forgot to turn the thermostat up. D'OH.

In the meantime I'll fire up the 535A for a quick burst of warmth. 

And entertainement of course!

[Cerebus]

In the meantime I'll fire up the 535A for a quick burst of warmth. 

Don't forget the marshmallows!

[Cerebus]

I have a few Mallory and Sprague caps here. Date code around 1959. Still test good.

Same date code as me, and I still test out good too.

Only downside is they are bloody huge compared to their modern counterparts.

[ Fx: Looks down.]  And that is also true too.
I'll leave the audience to judge whether I'm making a joke about my belly or my little charge pump.

[bd139]

  Suffering from same trouble at moment. An apathetic last quarter was not good. Decided I’m going to knock off some of it in the next few months as I’m fed up of hauling my own arse around. Need to buy a couple of 465’s to lift 

[WastelandTek]

  Guess it depends if you know why you are doing it.

because it was built in 1983?

[WastelandTek]

Is that a Bodnar pulser I see there on your bench grize?

It is indeed! Great little device.

did you print a case for it? what is the blue?

[Specmaster]

Suffering from same trouble at moment. An apathetic last quarter was not good. Decided I’m going to knock off some of it in the next few months as I’m fed up of hauling my own arse around. Need to buy a couple of 465’s to lift 

Hell I need to the same as well.