Test Equipment Anonymous (TEA) group therapy thread

[factory]

all the posts about hp5245's last week motivated me.

spent some time over the weekend and tested a pile of display boards.  found that many of the boards in the junk box were ok.

also found many with faults.  so far have repaired 6 of them. 

one had worn out neons in the display matrix.  would have expected them to die one at a time, but they were all dim and flakey even though the current limiting resistors and voltages tested good.

one had a wonky photocell matrix (the one printed on ceramic substrate in the readout block assembly).

and four had the same symptom of counting ok but not outputing a good carry pulse to the next decimal counter assembly.  all were repaired by replacing a silver mica in the output flip flop.  weird because the damn caps all tested good.......and silver micas are supposed to last forever. (it took me a long time to find this fix in the first one.....and it worked like a charm in all the rest).

the real puzzle is that some of the display boards in the junk box are unknown to me, and apparently not used in the 5245 family. 

anyone know what a 5232L-4B or 5245-6001 is used in?  (guess they will make good organ donors for the boards i have documentation for)



 

5232L-4B (2MHz/2Mc) is used in the 5243L for A16, I have documentation for it and a 5243L.
05245-6001 is used in the 5245L option 002 for A18, BCD output is +1248, I need to check if I have documentation.

Silver Mica caps do sometimes go bad, the silver migrates & causes shorts, which usually only show up at normal circuit voltages and not the low test voltages from LCR meters.

What are you using to replace the neons with? As I noted the NE-81 shown on various diagrams is obsolete, probably due to the mild radioactive additive for operation in darkness.

David

[Specmaster]

Mother-in-Law has LEDs in her kitchen and hallway, 4 fittings that take 3 G9 plastic body 2.8W LEDs each, and it seems that these LEDs are always blowing and at £14 for 4, far from cheap and this year alone I

I have 5 G9 in the kitchen. I found the G9 (replacements) to be very sensitive, the fluorescent lamps already cooked their electronics, most of the LEDs just kills themselfes (corn type bulbs) too. I had a pair where the LEDs fell of the board after removing the failing lamp... Now I have two cheap ones installed, that seem to be reliable, and one Osram type. Two of the fluorescents are still working.

With regard to LED bulbs - cooling is king, and as a rule of thumb in that regard, heavier bulbs are better.
Still, for isolation safety, they tend to pot the electronics (at least for the german market) - "dead weight" indeed! And it allows the supply electronics to get even hotter...
In general, physics has to be observed, the heat has to go from the LED-package to the environment.
A "corn cob" LED-bulb is an excellent example for a design where it is very hard to get the cooling right - best to avoid them in general.
Still, only the most cunning designs (of what I have seen) have the LEDs itself fail - usually the power supply fails before.

Source: I get my colleagues to bring their dead LED bulbs to me (to (seldom) repair and (often) harvest the LED). Repair is most often thwarted by "physically break to open" design.

@Specmaster: I am very surprised to hear of that many broken ones! But the small-packaged 230V ones are the most challenging (as power supply and led share the same puny heat"sink").
Are they not failing fast enough to get new ones via warranty?

Maybe, trouble is sourcing them in the first place. I have to grab them for her from where ever I can locate them. So that means that the failed lamps may have come from 1 of many suppliers and the lamps are unbranded due to their small size, there is no space for any details to be printed on them. The design of the LEDs themselves change by supplier, so unless precise records are kept, it is almost impossible to say which came from where.

The fittings themselves were chosen for their style rather than their substance, so she gave zero thought to future problems further down the line and M-I-L is one of those that knows best. She also feels ashamed if a single bulb fails in her fittings (3 per fitting) and she has to have the bulb replaced almostly immediately as she claims that people will be talking about her with her bulbs not working  , even though nobody outside could even detect it, she convinces herself that they can and do 

[mnementh]

Was it just he, or did the firum go * for a few minutes there?

*Total Inability To Support Usual Performance

Yes.

Fuck... guess I've been T.I.T.S.U.P. since the Cheney Administration... 

mnem
*toddles off to shop for something like Red Bull that doesn't taste like pustulent ass*

[mnementh]

...The fittings themselves were chosen for their style rather than their substance, so she gave zero thought to future problems further down the line and M-I-L is one of those that knows best. She also feels ashamed if a single bulb fails in her fittings (3 per fitting) and she has to have the bulb replaced almostly immediately as she claims that people will be talking about her with her bulbs not working  , even though nobody outside could even detect it, she convinces herself that they can and do 

I'm not talking about your MIL's err... bulbs.   

mnem
...or her fittings.

[Cerebus]

*toddles off to shop for something like Red Bull that doesn't taste like pustulent ass*

[Specmaster]

I suspect IKEA chooses those threads based on regional availability to drive customers back to them for replacements; obviously the IKEA-branded bulbs don't last hugely longer than the competition, as most of the IKEA lamps I've bought come from the Thrift, and have dead bulbs. Doubtless the reason they wound up at the Thrift is the owner got annoyed over poor availability of suitable replacements and... the cycle continues.

mnem
 

Nah, I think the real reason is that Ikea only sell their own gear and so that gear will be what is the European standard and those "E" threads on their lamps are the norm. Personally I think they are dangerous as it perfectly possible to get the metal cap / thread connected to the hot or live wire and if that is so connected than that lamp during the replacing cycle has the potential of giving the unsuspecting person removing the lamp, a nasty shock. 

[Cerebus]

I suspect IKEA chooses those threads based on regional availability to drive customers back to them for replacements; obviously the IKEA-branded bulbs don't last hugely longer than the competition, as most of the IKEA lamps I've bought come from the Thrift, and have dead bulbs. Doubtless the reason they wound up at the Thrift is the owner got annoyed over poor availability of suitable replacements and... the cycle continues.

mnem
 

Nah, I think the real reason is that Ikea only sell their own gear and so that gear will be what is the European standard and those "E" threads on their lamps are the norm. Personally I think they are dangerous as it perfectly possible to get the metal cap / thread connected to the hot or live wire and if that is so connected than that lamp during the replacing cycle has the potential of giving the unsuspecting person removing the lamp, a nasty shock.

Swings and roundabouts innit. If you've got a BC lighting socket somewhere where you have to feel for it with your fingertips (often because a lampshade obscures it from you when you're standing on a ladder) you have much more chance of sticking your fingers across the contacts than you have of getting your finger across live and neutral on an ES socket. Also I hate the wibbly-wobbly feeling of lamps in BC sockets - if you're going to have a bayonet lock then why can't it be one where the pins aren't half the size of the slots that they ride in?. You're never quite sure whether you've engaged it properly, or whether the springs are going to pop the fragile lamp out (straight onto a concrete floor knowing my luck) the second you let go of it.

And don't get me started about trying to align the pins at both ends of a 5' fluorescent tube when you can only get a ladder up near one end; and then you have to twist the thing to get it to engage. Who thought that fiddly little pins were a good idea for something that is pretty much always accessed by ladder? Eh?

I'd swear that a lot of the household things we use everyday were designed by idiots and sadists. Would it really have hurt them to make the corners on Lego bricks a little less sharp?

[nixiefreqq]

all the posts about hp5245's last week motivated me.

spent some time over the weekend and tested a pile of display boards.  found that many of the boards in the junk box were ok.

also found many with faults.  so far have repaired 6 of them. 

one had worn out neons in the display matrix.  would have expected them to die one at a time, but they were all dim and flakey even though the current limiting resistors and voltages tested good.

one had a wonky photocell matrix (the one printed on ceramic substrate in the readout block assembly).

and four had the same symptom of counting ok but not outputing a good carry pulse to the next decimal counter assembly.  all were repaired by replacing a silver mica in the output flip flop.  weird because the damn caps all tested good.......and silver micas are supposed to last forever. (it took me a long time to find this fix in the first one.....and it worked like a charm in all the rest).

the real puzzle is that some of the display boards in the junk box are unknown to me, and apparently not used in the 5245 family. 

anyone know what a 5232L-4B or 5245-6001 is used in?  (guess they will make good organ donors for the boards i have documentation for)



 

5232L-4B (2MHz/2Mc) is used in the 5243L for A16, I have documentation for it and a 5243L.
05245-6001 is used in the 5245L option 002 for A18, BCD output is +1248, I need to check if I have documentation.

Silver Mica caps do sometimes go bad, the silver migrates & causes shorts, which usually only show up at normal circuit voltages and not the low test voltages from LCR meters.

What are you using to replace the neons with? As I noted the NE-81 shown on various diagrams is obsolete, probably due to the mild radioactive additive for operation in darkness.

David

thanks!  do not have a 5243l and do not expect to find one.  don't remember ever seeing one in all my years of counter hunting at fests.

had some really beat up display cards with missing parts.  stole the neon block from one of them.  it also gave up its photo resistor matrix.

really expected to find bad transistors in those non-working boards.  nope.  it really is a mistake to begin trouble shooting with preconceived notions.

geeeeeze....if you can't depend on silver micas what can you depend on?

[mnementh]

*toddles off to shop for something like Red Bull that doesn't taste like pustulent ass*

Mmhmmm... slightly less addictive, and probably less stressful on the ol' kidneys as well. SOLD! I'll take 3 cases, please...

mnem
Guess I'll need to increase my Lisinopril...

[Specmaster]

I suspect IKEA chooses those threads based on regional availability to drive customers back to them for replacements; obviously the IKEA-branded bulbs don't last hugely longer than the competition, as most of the IKEA lamps I've bought come from the Thrift, and have dead bulbs. Doubtless the reason they wound up at the Thrift is the owner got annoyed over poor availability of suitable replacements and... the cycle continues.

mnem
 

Nah, I think the real reason is that Ikea only sell their own gear and so that gear will be what is the European standard and those "E" threads on their lamps are the norm. Personally I think they are dangerous as it perfectly possible to get the metal cap / thread connected to the hot or live wire and if that is so connected than that lamp during the replacing cycle has the potential of giving the unsuspecting person removing the lamp, a nasty shock.

Swings and roundabouts innit. If you've got a BC lighting socket somewhere where you have to feel for it with your fingertips (often because a lampshade obscures it from you when you're standing on a ladder) you have much more chance of sticking your fingers across the contacts than you have of getting your finger across live and neutral on an ES socket. Also I hate the wibbly-wobbly feeling of lamps in BC sockets - if you're going to have a bayonet lock then why can't it be one where the pins aren't half the size of the slots that they ride in?. You're never quite sure whether you've engaged it properly, or whether the springs are going to pop the fragile lamp out (straight onto a concrete floor knowing my luck) the second you let go of it.

And don't get me started about trying to align the pins at both ends of a 5' fluorescent tube when you can only get a ladder up near one end; and then you have to twist the thing to get it to engage. Who thought that fiddly little pins were a good idea for something that is pretty much always accessed by ladder? Eh?

I'd swear that a lot of the household things we use everyday were designed by idiots and sadists. Would it really have hurt them to make the corners on Lego bricks a little less sharp?

Those bleeding bi pins on tubes are even more fun to line up when on a ladder and the light fitting is hanging on chains, lots of fun and games can be had swapping tubes in those conditions 

[mnementh]

@Specmaster - "E threads" or ES base just means Edison Screw base; measured in mm across the major diameter, and the standard applies worldwide, including the US. E17 used to be quite commonly used for exterior 120VAC C9 profile Christmas bulbs in the US, but now no longer aside from appliances, ceiling fans and desk lamps, so the mega-stores rarely have any real selection thereof. E17 now are one of the few sizes that still lingers as incandescent for this reason; or at least, as of a year or so ago last time I shopped them.

The only ones you could consider a "European" standard are E14 and E27; but even these have been showing up in  the US more and more over the last decade or two as the internet makes European "local designer" lighting products available to a global market. E14 is primarily a candelabra base like E12; E26/E27 have generally been homologated into one design by cheap Chinese manufacturing.

C - I totes agree about the insanity of fluorescent lighting "standards"... particularly CFLs went batshit cray-cray in the 70s-00s, as this chart shows.  EDIT: Yes, I know this was done to ensure that the ballast built into a lamp only got an appropriate fluorescent tube fitted, but still seriously

As for Legos... I quite enjoy the meditative nature of making big structures with shiny, smooth walls out of standard bricks, so the misery of their sharp corners underfoot is something I'll continue to consider part of "the joy of the medium". 

mnem
*toddles off to shop for some X-mas lights*

[WastelandTek]

the sadness

https://www.ebay.com/itm/284564868035?hash=item4241634bc3:g:HBwAAOSwJAVhKNoR

[med6753]

the sadness

https://www.ebay.com/itm/284564868035?hash=item4241634bc3:g:HBwAAOSwJAVhKNoR

He already pilfered the 12AX7, 12AU7, 6DJ8 tubes out of all of them apparently. I won't say what I'd like to see happen to his little collection for fear that karma may come back and bite me in the arse. 

[Specmaster]

@Specmaster - "E threads" or ES base just means Edison Screw base; measured in mm across the major diameter, and the standard applies worldwide, including the US. E17 used to be quite commonly used for exterior 120VAC C9 profile Christmas bulbs in the US, but now no longer aside from appliances, ceiling fans and desk lamps, so the mega-stores rarely have any real selection thereof. E17 now are one of the few sizes that still lingers as incandescent for this reason; or at least, as of a year or so ago last time I shopped them.

The only ones you could consider a "European" standard are E14 and E27; but even these have been showing up in  the US more and more over the last decade or two as the internet makes European "local designer" lighting products available to a global market. E14 is primarily a candelabra base like E12; E26/E27 have generally been homologated into one design by cheap Chinese manufacturing.

C - I totes agree about the insanity of fluorescent lighting "standards"... particularly CFLs went batshit cray-cray in the 70s-00s, as this chart shows. 

As for Legos... I quite enjoy the meditative nature of making big structures with shiny, smooth walls out of standard bricks, so the misery of their sharp corners underfoot is something I'll continue to consider part of "the joy of the medium". 

mnem
*toddles off to shop for some X-mas lights*

Yes, I knew that the E was Edison screw, but I just never realised that it was as popular in the good old USA, albeit a different size. Most lampholders are inherently dangerous if a person can contact metal, used as a contact. This is the reason my old company Crabtree Electrical developed the safety BC lampholder with numerous safety features to many to go into at this late hour, 02.35 in the morning, I'm orf to beddddd for some ZZzzzzzzzz. 

[Cubdriver]

the sadness

https://www.ebay.com/itm/284564868035?hash=item4241634bc3:g:HBwAAOSwJAVhKNoR

He already pilfered the 12AX7, 12AU7, 6DJ8 tubes out of all of them apparently. I won't say what I'd like to see happen to his little collection him for fear that karma may come back and bite me in the arse. 

Fixed that for you.  And I'm biting my tongue, too.  Fucking ghoul.

-Pat

[mnementh]

Yeah, and he STILL has the wording of the listing as being for a single scope with a starting bid of $2400. He's fucking batshit crazy is what he is. Or he's trying to do some sort of insurance scam.

mnem
 

[Zucca]

-Pat

Hey Pat are you happy with your LAG-120?
Since an AC power source is too expensive, I maybe divert on a audio sig generator.
Hewlett-Packard 209A?

Funny

[Cubdriver]

Hi Zucca -

I'd go with the HP in preference to the Leader.  This one at least has a wee flat spot on the negative half cycle of the sine wave output (it's connected to the scope through a 600 ohm feedthrough terminator in this pic, so impedance-wise it should be happy):


In its defense, I never bothered to troubleshoot it and have since buried it here somewhere - it may be as simple as a bad PS cap or a misadjusted gain pot inside, so I guess I shouldn't condemn it too harshly, but once I got an HP 339A I started using its oscillator so the Leader was serving no purpose at that point.

-Pat

[Zucca]

Thanks Pat,

such a big knob with few switches are so useful... no need to go in menu of menus to set up the stuff.

[mansaxel]

Nah, I think the real reason is that Ikea only sell their own gear and so that gear will be what is the European standard and those "E" threads on their lamps are the norm. Personally I think they are dangerous as it perfectly possible to get the metal cap / thread connected to the hot or live wire and if that is so connected than that lamp during the replacing cycle has the potential of giving the unsuspecting person removing the lamp, a nasty shock.

<rant type=repeated>

• E stands for Edison, so a very European standard it isn't.
• I do not care if phase or neutral is in the thread. I can't know, at least for movable fixtures. Since they're built right, this is not a problem. It is a false sense of security to rely on phase and neutral being at the right place in all single-phase appliances. In wiring, it matters, in three-phase with neutral it matters, but in appliances, if it matters, the manufacturer did it wrong.
• Look at any maritime mains installation: Since you very much do not want to play electrochemist with your cargo ship and the North Sea (currents in the hull), all mains is Delta 220V and 60Hz. Both holes in the Schuko are live to ground, granted only 127V, but that is enough to harm.  Same in on-shore in Norway, btw.

[mansaxel]

I'd swear that a lot of the household things we use everyday were designed by idiots and sadists. Would it really have hurt them to make the corners on Lego bricks a little less sharp?

They haven't stopped. The GU10 socket is one of those; fit once (or rather: fit, if you're lucky, on 4th try), up on that ladder, and then, never get out..  It often is seen on PAR 16 style lamps, that fit snugly into a small armature, so you can't get a grip on the sides of the lamp body, but must press the face in and use what little friction you have in the finger-glass interface to twist two heat-treatedfused metal parts off of each other, when there's a spring action chipping in on the holding side..

A sturdy socket, yes.

[Robert763]

Fitings using recessed GU bayonet lamps should come with a rubber sucker to aid removal.
The socket is basically the same as that used for fluorescent lamp starters.

[mansaxel]

Fitings using recessed GU bayonet lamps should come with a rubber sucker to aid removal.
The socket is basically the same as that used for fluorescent lamp starters.

Yes, they sometimes do come with a sucker; once, on an Osram lamp, I've ended up with the front plastic of the lamp on the sucker, and the rest in the lamp holder...

However, as they in general are fit-and-forget, I am not too bothered.

[Neper]

Another one from the popular series "Fun with exotic lightbulb sockets":

Here in Germany, it's always been either E14 or E27. When a friend who had spent most of her life here inherited a house in the North of France she took all her German lamps with her. We helped her move.

When we mounted the big lamp in the living room, the lightbulbs had disappeared. So, off we went to get some new ones only to find that in this part of France everything is (or at least used to be) bayonet. Last chance: Bridenne, the store that had everything... if they could find it. All the staff was family. You had to grow up there to find your way through heaps of merchandise, not only in the shelves but also on the floor.

Lightbulbs with E27? Yes, Madame Bridenne was sure she had seen a few... just last week. Ten minutes later we left with 6 new... well... NOS... Osram bulbs. Drove back. Screwed them in, switched on, ZAPP!! Blackness. Fuse blown, all bulbs burnt out without a trace of the filament inside. What the Dickens (who is a very popular figure in Boulogne)? Connected across two phases? No. There was only one.

That's when we had a closer look at the boxes those bulbs came in. The stamps were quite faded but visible if you knew where to look: 24 Volt. Took them back to the shop. Got a refund and their sincere apologies. They had no idea we weren't buying them for our boat. Apparently, E27 was current aboard the local fishing fleet. But nowhere else.

[mansaxel]

Another one from the popular series "Fun with exotic lightbulb sockets":

Such a wonderful R16 on the picture. My next-to-earliest memories are from R16 trips. We upgraded from R4 to R16 when I was perhaps 4 years old; and then a couple years later we went to Passaten, after which it was Volvo 245, 744, and then back to VW, this time Polo. By that time I'd moved away from my parent home, so didn't drive them that much. I learnt to drive in a 1982 Volvo 245.