+Fran Blanche Good tip Fran.

confirmed - last one I did I used a good amount of contact cleaner, good as new!

Seriously, Dave. You didn't suspect an electromechanical fault immediately when you saw the ranges randomly come good while you were mashing buttons? I am disappoint. The 30KV discharge could have been a red herring, but it could easily have carbonized the contacts on that switch as well. Dave often says that Commandment #1 is "Thou shall test voltages." I'd say "Thou shall clean all contacts" is Commandment #0.

Darthane I spent a good deal of hours recently trying to debug an MSP430 interpreter/emulator after adding a direct-interpreter sub-mode (it would use a faster threaded-code/trace based decoder/interpreter executing from ROM, and a slower direct-interpreter for RAM where self-modifying code is more likely, and would otherwise require flushing the trace-cache). spent a long time (much of a day) trying to hunt for a bug in the actual interpreter logic. turns out it was a bug in how I had rigged up the test to force the direct interpreter to also run code in ROM, conflicting with the logic for passing control back to the trace-interpreter whenever ROM addresses were detected. made both places use a shared predicate function, so now I can force the direct interpreter simply by disabling the check for ROM addresses.

Brendan Bohannon Can agree. It's awful when you think your program is wrong, when it's actually the testing that is incorrect. I've been writing ROMs to test an emulator I'm making, and have gotten into all sorts of confusion based on my testing ROM being incorrect. Plus the documentation for this stuff is awful.

Prehistoricman yeah. generally spent a fair bit of effort trying to figure out things which were poorly explained in the documentation. I wrote an emulator for the chips partly as I am using them in some projects (mostly the MSP430G2xxx DIP14 and DIP20 chips). I was not very impressed with the existing emulators I had tried, which seemingly couldn't emulate the chips in real time, and didn't have much in the line of being able to log/analyze output or simulate external peripheral hardware. so, I threw together an emulator, thus far have it running around 90 MIPS on my PC (a fair bit faster than the real HW), and am working on integrating it with a real-time/interactive electronics simulator of mine (sucks hard at analog components though). the idea is basically to be able to drop an MSP chip into the simulation and connect up peripherals (and have a ok idea how it will behave). another possible use is supplying a ROM image and some inputs (high/low or a logical pin voltage), and then logging the pin outputs at a fixed logical frequency (probably 48kHz). I have done similar for code I have targeting ARM devices, where generally I use WAV for recording GPIO outputs (though, generally, this has been by building the code on a PC and using stubs to fake the external hardware).

Brendan Bohannon Sounds like you have some big tasks on hand!

Prehistoricman not particularly. I threw together the interpreter over a few days, as the MSP430 is actually a fairly small/simple ISA vs some of the other things I have written interpreters for. the electronics simulator has been on/off effort for a few months, but is mostly held back some by me being "not really all that sure what I am doing" on the math front. I discovered fairly quickly on that Ohm's Law by itself doesn't apply so good to simulation (applying it basically requires being able to look at a circuit top-down and apply some amount of intuition, but it doesn't hold up so well if applied bottom-up with each component acting independently). so, early on I had ended up treating volts and ohms as the fundamental units, and trying to infer everything else from volts and ohms, didn't work well (and amps doesn't hold up well in use, but with just volts and ohms, you get amps coming out of nowhere). considered now trying to rework it to a system based on volts, ohms, and potential watts (where Pi=Pw/V and I

do you know why each of these switches has a different amount of a buttload of contacts?

Tjita1 German tecnology :D

Tjita1 Yeah, I noticed that too.

AlainG80 It's used in several parts of Europe (here in Sweden among others), and it's called Schuko, although the real name is CEE 7/4. I should know, since every single grounded doohickey here in Sweden uses it.

Yeah, I located it again in the video and checked, it's definately a Schuko.

Tjita1​ Indeed, the french ground has been blocked by a bar @kzfaq.info/get/bejne/ocpzmaSDlZyrlX0.htmlm37s I withdraw my comment.

***** yes 1 cent more per hour

***** Yeah, I could have just edited out all the garden path testing and made it look like I magically found the switches, but that's not the least bit interesting. Warts and all is far more interesting.

Mark Jordan been there done that

Mark Jordan TVs tend to be harder than most things. Try with simpler appliances first.

Was really a bummer...thought I had it figured out...installed the new parts and flipped it on and crap picture...it's ow in the dumpster. Think your right...gunna try some easier stuff.

Mark Jordan Hey, failed projects are the bread and butter of learning. I understand what I'm working on a little bit better if my first attempt goes up in flames!

zx8401ztv Ah, ok, could be the short, that makes sense. The switches did not seem that dicky to me to begin with, not enough to be important, I did more playing off camera various times and there were things that pointed away from dicky switches. Only once analysed did the dicky switches become fairly apparent as the main culprit.

EEVblog I have an old fluke 8050a that becomes silly if its not used for a while, one day i will desolder all the switches and frighten them with a clean lol. Also i found parts of the front plastic panel and pcb became slightly conductive, ive never seen plastic do that before, odd that lol :-D

Stuart Wilson lol yep im sure your right :-D Old chinese proverb says: "Check the simple before the complex, but do the reverse when there is a "D" in the week" :o)

zx8401ztv All them switches had holes in the end, an easy place to squirt some stuff, esp if you tilt it with face down, well worth doing all them just to make sure, plus tidy up the inside (maybe that bridge rectifier, blown resistor just because etc...), its still a decent bench meter

jusb1066 Yes it is a nice multimeter :-D and far more accurate than most people need for basic electronic repairs, the two chip adc just reminds me of the icl7106 thats used in just about every cheap multimeter in the past, they work really well with the correct parts added :-D The quality of the attenuator resistors and reference voltage is the part that matters the most, spot on dc voltage and excellent ohms ranges. I have an old fluke 8050a i use for a reference to set my cheap meters by, its old as the hills but still usefull :-D

Tear down of a Boeing 777 :)

You are under FBI watch for that.

iPelaaja1 I would have preferred a "shootout" video.

Too bad Dave (1) tries to take credit for it "as I uh, you know, originally sortof uh started to suspect there"... He does know a lot of stuff, I'm learning a lot here, but his character sucks big time.

SaturnV2000 The -1.2V is (now) obviously only valid with TP1 and TP2 still shorted as per a previous step. I should have twigged to that.

EEVblog Yeah, I see that now . . .

HunChem exorzist.....;)

Yeah, at 40:15 checking U14 at 0.666v... Dave, your meter is possessed. ;)

noise vector :: dj tremor :: dusp2k Doesn't make them any less funny to an Aussie.

In germany too

EEVblog the same applies to us for your plugs.

EEVblog they are 230V, normally

EEVblog As we think, yours is funny ;) btw. thse Plugs are used for 240V systems - its not your so called Yankee-Plug

Spinning Quad Sorry, already gone.

EEVblog thanks anyway. Love the blog.

Кирилл Рагузин These Isostat switches have silver-plated contacts and leads combined in one piece. Silver blackens and there's your problem. They also usually have some grease in them that can react with the metal making it worse.

oil not conductive