Test Equipment Anonymous (TEA) group therapy thread

[bd139]

I agree 100% with you. I’ll perhaps prototype one stage on this with 10 connections max then transfer it to soldered. Typical example is the CW filter I just built. I did one stage of the filter to tweak the values and part spread that LTspice was a little too ideal on, built half the next stage to check impedances and then transfer 4 stages to matrix board. The other option is soldering sockets or headers into your final prototype which is even less reliable over time.

Those crazy suckers who build a whole CPU or mixed signal system on one are nuts but there’s value in testing subcircuits.

[Specmaster]

Anyone know where I can  get a replacement LCD screen for a Fluke 25/27 from in the UK? I noticed that on resistance range the open circuit was causing the OL on the screen to shimmer slightly. I took it out used a cotton bud with Isopropyl on and gently cleaned the screen connections and also the zebra strips and re-assembled it, now the 2nd digit from the right has no B & C segments 

I have swapped the zebra strips around to no avail, took a screen one of my other meters and fitted with the original zebra strips and it works so it should just be the screen itself.

[Mr. Scram]

Anyone know where I can  get a replacement LCD screen for a Fluke 25/27 from in the UK? I noticed that on resistance range the open circuit was causing the OL on the screen to shimmer slightly. I took it out used a cotton bud with Isopropyl on and gently cleaned the screen connections and also the zebra strips and re-assembled it, now the 2nd digit from the right has no B & C segments 

I have swapped the zebra strips around to no avail, took a screen one of my other meters and fitted with the original zebra strips and it works so it should just be the screen itself.

The zebra strips are very notorious, so I'd triple check to make sure it's not those.

[Specmaster]

Anyone know where I can  get a replacement LCD screen for a Fluke 25/27 from in the UK? I noticed that on resistance range the open circuit was causing the OL on the screen to shimmer slightly. I took it out used a cotton bud with Isopropyl on and gently cleaned the screen connections and also the zebra strips and re-assembled it, now the 2nd digit from the right has no B & C segments 

I have swapped the zebra strips around to no avail, took a screen one of my other meters and fitted with the original zebra strips and it works so it should just be the screen itself.

The zebra strips are very notorious, so I'd triple check to make sure it's not those.

I know so I have cleaned them with some Isopropyl and wiped them dry and refitted them, still the same. I have also reversed so that the top one is the bottom and also tried reversing them so the PCB side is now on the glass etc, still the same 2 segments.

[mnementh]

You're right about stuff being bigger. For what I was going to pay for a house in Staines, I can get a 7 bedroom detached house with double garage in Lincolnshire.

You realise there's a reason for that, don't you!

I've found a nice place: 4 miles from the city centre, with farms, deer and peregrines between me and the city. The city has two universities and hence a nice zing to the place, and has recently been voted one of the hippest cities. Plus the food/restuarants are excellent, and wonderful countryside is nearby.

On the downside, unlike flatland, there are limited conversations about wheat and brussel sprouts, and there is less sky.

That sounds like the perfect compromise. I used to live just outside Nottingham (Radcliffe on Trent) and had a similar situation a long time ago but local work dried up so we bailed out back to London. This was before the rise of working from home.

My eldest, who is now much much older had a problem. When we were pushing her around in her buggy, old ladies kept giving her pound coins when we weren't looking for a few seconds. This inevitably nearly turned into a choking hazard. That and some of the locals you just can't understand. I assume that they were talking about wheat and sprouts too

... the sound of enlightenment

It's a warm fuzzy noise.

On the subject of quality items, get it while it's hot: https://www.ebay.co.uk/itm/152816088283

Got mine    RS are selling these at about £46 a pop with VAT at the moment.




Yes solderless breadboards suck but this sucks the least out of all of them and I do use them regularly for quick test runs on ideas and bias calculations / sanity checks etc. Every single hole contains the connector equivalent of a Moray Eel.

The old homestead was about 45 minutes from anything like a city... about 230 acres of farmland in the middle of the Finger Lakes region of central New York.

Because, as my grandparents used to say: "If you can see your neighbors, they're too damned close."

I used to be  "I wanna be able to GO SOMEWHERE & DO SOMETHING!" when they said this as I was growing up; now I'm  "Oh HELL yes."




When I was taking my first electronics courses, we received an all-in-one "Electronics Lab" very similar to this one, only the breadboard area was 2 large breadboards stacked about 10" x 12". It had the same stuff built in; AF function gen, digital VM, +5/+12/Variable PS, a few 74LS and some LEDs/LED drivers/Modules, speaker, some pots & switches.

I wanna say it was made by ELENCO; was the same "Weller blue" too. I screwed it to a board with some spools of telephone wire instead of trying to keep track of all the scraps of jumper wires that came with it.  I kept that thing for decades... any time I needed to do a quick reality check on a circuit I was working on, out it came.


mnem
*Sigh*

[mnementh]

Anyone know where I can  get a replacement LCD screen for a Fluke 25/27 from in the UK? I noticed that on resistance range the open circuit was causing the OL on the screen to shimmer slightly. I took it out used a cotton bud with Isopropyl on and gently cleaned the screen connections and also the zebra strips and re-assembled it, now the 2nd digit from the right has no B & C segments 

I have swapped the zebra strips around to no avail, took a screen one of my other meters and fitted with the original zebra strips and it works so it should just be the screen itself.

The zebra strips are very notorious, so I'd triple check to make sure it's not those.

I know so I have cleaned them with some Isopropyl and wiped them dry and refitted them, still the same. I have also reversed so that the top one is the bottom and also tried reversing them so the PCB side is now on the glass etc, still the same 2 segments.

Did you clean the contact area of the LCD with alcohol? cleaning BOTH was how I kept my 1st gen 87 alive for 20 years with the original LCD and zebra strip. I did upgrade the BL with a really bright white LED about 5 years ago though.

mnem
"Don't be afraid to smack 'im upside the haid if 'e's gettin' on yer nerves; I do it alla time."

[Seich]

So in a moment of weakness I bought this EDC 501j off of ebay. It was listed as for parts so I took a gamble. Seems to have paid off  .

[Specmaster]

That is a lucky strike, you did well there for sure.

[Mr. Scram]

Or you know both are off by the same amount 

[Specmaster]

Anyone know where I can  get a replacement LCD screen for a Fluke 25/27 from in the UK? I noticed that on resistance range the open circuit was causing the OL on the screen to shimmer slightly. I took it out used a cotton bud with Isopropyl on and gently cleaned the screen connections and also the zebra strips and re-assembled it, now the 2nd digit from the right has no B & C segments 

I have swapped the zebra strips around to no avail, took a screen one of my other meters and fitted with the original zebra strips and it works so it should just be the screen itself.

The zebra strips are very notorious, so I'd triple check to make sure it's not those.

I know so I have cleaned them with some Isopropyl and wiped them dry and refitted them, still the same. I have also reversed so that the top one is the bottom and also tried reversing them so the PCB side is now on the glass etc, still the same 2 segments.

Did you clean the contact area of the LCD with alcohol? cleaning BOTH was how I kept my 1st gen 87 alive for 20 years with the original LCD and zebra strip. I did upgrade the BL with a really bright white LED about 5 years ago though.

mnem
"Don't be afraid to smack 'im upside the haid if 'e's gettin' on yer nerves; I do it alla time."

I did clean both of the contact parts of the LCD screen and also the zebra strips, both sides and I have also reversed the zebra strips to see if the was a dead section in them, the theory being that if there was a duff section or bad contact, if I moved their positions then the bad section would cause other segments to fail, but thats not the case. The duff segments are the same ones. 

[Specmaster]

Or you know both are off by the same amount 

Thought about that and tried zebra strips from another meter, same segments at fault. 

[mnementh]

Hmmmm...


mnem

[bd139]

Display connections may have given out on the LCD screen.

Start digging a hole in the garden.

[Seich]

Or you know both are off by the same amount 

I thought that might be the case but it also seems to agree with my HP 3478A. So that being the case becomes less likely I'd think. 

[Specmaster]

Display connections may have given out on the LCD screen.

Start digging a hole in the garden.

It requested no flowers please.

[tggzzz]

I thought that might be the case but it also seems to agree with my HP 3478A. So that being the case becomes less likely I'd think. 

A quick and dirty sanity check that tests every switch/resistor is, of course, 0000,1111,2222,3333,4444,5555,6666,7777,8888,9999

[mnementh]

Or you know both are off by the same amount 

I thought that might be the case but it also seems to agree with my HP 3478A. So that being the case becomes less likely I'd think. 

And so the obvious question is... why didn't he lead with the 5 1/2 digit meter?

I smell a rounding error, m'self. 


mnem
Pants are highly overrated.

[mnementh]

A quick and dirty sanity check that tests every switch/resistor is, of course, 0000,1111,2222,3333,4444,5555,6666,7777,8888,9999

I failed my Turing Test.


mnem
Sanity is ALSO highly overrated. Just ask any US Congressman.

[Seich]

Or you know both are off by the same amount 

I thought that might be the case but it also seems to agree with my HP 3478A. So that being the case becomes less likely I'd think. 

And so the obvious question is... why didn't he lead with the 5 1/2 digit meter?

I smell a rounding error, m'self. 


mnem
Pants are highly overrated.

I don't have long enough leads.

[beanflying]

Vintage arcade game for TEA 



Instadivorce version Tube tester for TEA members 

[mnementh]

Gawd, I feel old.

I remember Ted Bosch, the guy who gave me my first job doing electronics repair (in the AV Dept of the local high school) telling me "Those aren't a tube tester; they're a people tester." He explained that the only thing they would really tell you was whether a tube was shorted cathode or filament open; otherwise they were so inaccurate as to be useless. He further conjectured that this was quite possibly deliberately so.

For over 30 years, I kept an old B&K DynaScan 667 (Ted had a 747... that thing was a proper boat anchor with a bazillion knife-lever switches and a ginormous meter like something out of an episode of "The Outer Limits) Tube tester and a CRT Tester "Rejuvenator" from the same series (which worked by overdriving the filament voltage and accelerating anode voltage, then applying an AC voltage to burn away some of the surface of the cathode to temporarily increase emission on a weak CRT); I wanna say a 466, but we had many at the various shops I worked at over the years. I made a small fortune with that thing in the 90s and later; word got around the arcades that I still owned one and wouldn't hassle them to do the expensive job of replacing a CRT every time they called me in to "brighten up a few games".

Meh. It was quick easy money, and when the time came to really fix it, guess who they called?


mnem
"Oooh, man... looks like the posistor leaked into the ion trap and it overflowed... we're gonna have to drain it. I've got the tools; ain't nuthin' but time." *Lights cigar with a butane soldering iron and smiles*

[bd139]

That sounds about right. Lots of cowboy outfits selling new stuff that wasn't required back then which is what resulted in the "tube tester" stations. Transistors were actually the worst. The old Ge ones in half the UK built sets were terribly unreliable so they used to retrofit silicon ones as an option. This turned out to be lucrative because the bias conditions were different so you had to replace more bits and therefore charge more. CRT rejuvination actually works pretty well though, at least for a bit and makes people happier than saying "you need to buy a new CRT".

My mother had a job in the early 1980s working at one of the very few traditional local radio shops in London that still did repairs and wasn't a rip off merchant. Mainly for little old ladies who's woody had blown up. They refused to use a valve tester because to quote the guy in the shop, it was pretty bloody obvious when a valve was knackered. Plus he was too cheap to buy anything reputable. This is the guy who at the time was still driving a car (Humber I think) he bought just before WWII that had no windows in it other than the windscreen because they got blown out during a bomb blast. Glas was expensive so he just welded the holes shut and turned it into a van.

I remember going in there on a Saturday and was shown how to use the wax out of knackered capacitors to seal the tops of IF transformers to stop them from drifting because it was cheap

Damn I miss the twilight zone of technology back then. Got one old lady with a 1950 set in and a guy with a ghetto blaster in at the same time and they're selling computers (Sinclair ZX80s)

[Specmaster]

Showing your age here, but they were good old days weren't they? Most of the big radios around then seemed to be woodys then became Bakelite, and we had those god awful cheap little pocket trannies about the size of a cigarette packet, god they sounded awful. Local radio/electronic shops seemed to be almost everywhere, most towns had at least one or two, pirate radio stations abounded and we had a thriving motor industry and the roads weren't full of bleeding pot holes either.

I remember as a lad, I'd stand and drool over all the electronic gadgets in the shop windows of my local radio shops and there was about 4 or 5 in Chelmsford back then, brought my first oscilloscope at the age of 17 from one of them. That Humber your boss drove brought back memories of other good British cars of the era, Armstrong Siddeleys, Rovers, Austin Westminster, Austin Sheerlines, Wolseleys, Vanden Plas, Rileys, Lagonda's, Jags, Daimlers and Lanchesters, most of which have long since disappeared.

[bd139]

Agreed. The amount of decent scrap that came out of that era was amazing. I could get stuff I needed out of charity shops, car boot sales and jumble sales. Buying it new now from China is most economical. I have actually considered joining BVWS because of their auctions ( https://www.bvws.org.uk/ ) just to get a look in on all that again. Check the ending prices of some of the stuff on their web site. Auctions are at Harpenden as well which isn't a big trek. Lots of test gear appears in there.

Talking of shitty transistor radios, I saw this on ebay and couldn't resist: https://www.ebay.co.uk/itm/181871312895 - going to build it, then add a BFO and see if I can bend it to top band so I can tune into the comedy bitching on 1933KHz from the "gentlemen of 1933".

Car I always wanted was the Rover SD1. This desire has only recently been replaced by Gene Hunt's Audi Quattro 

[med6753]

The Fluke 8800A arrived yesterday in one piece. The seller did an excellent job with the packaging. It was in a large box surrounded by peanuts plus the unit itself was bubble wrapped. I didn't fully appreciate how much larger an 8800A is compared to a typical 8000A or 8600A in both height and length. And it's heavy! When I got it the cover off it became very clear. This thing is built like a brick shithouse. Metal covers top and bottom plus an all metal chassis. That's the good news.

The bad news is that it powers up but that's about it. The display flashes random numbers. None of the functions work. And certain switch positions cause the power transformer to start screeching. Clearly we have some major problems. I did some initial checks of the power supply and all voltages are good except the +35V source. It's reading +25V so something is loading it down. This unit is loaded with tants so I think my approach right now is inventory all of them and do a mass replace plus do the filter caps too. Then assess where I'm at and take it from there. Anyone aware of any other areas to check? I know the reed relays and the front switch panel can be problem areas so I'll be checking that. I'm also going to contact the seller. I'll praise him for his packaging but see if he's willing to do a partial refund. I have no intention of sending it back. One way or another I'm going to fix it.