Bit rot in micro controllers?

I don't want a kitchen stove that is uP controlled. That's a horrible environment for cheap electronics. If you want to buy a non-digital kitchen range, expect to pay a large multiple over the GE-type electronic junk. Wolf, Viking, Bosch do good brass.

Our house came with a double oven. For some reason, one section has electronic controls and one has the classic pneumatic-mechanical thermostat. Guess which one still works.

It definitely doesn't commit any button presses to EEPROM as it forgets every single one of them after a power outage.

That sure is my hope though then I'd expect the LED bar graph to become iffy and it doesn't.

Oh, that doesn't sound good. In that case I'd rather redesign it to fully analog. Seems like less work and then it'll never fail again.

My Wavetek 23 funtion generator lost EPROM content as well but not after

I still have some HP gear, HP3577A and HP4191A. Time to let those go I guess, now that I retired.

I hope so as that's wasy to fix :-)

Have to wait for warmer days to look though because the missus doesn't like it cold downstairs.

Luckily this stove has hardware safety interlocks for vacuum and proof of fire which the CPU cannot override.

This has a linear power supply but yes, when the weather gets warmer I'll take it apart and check.

However, this one live in a pellet stove. Though it doesn't get sizzling hot, you can still touch it.

:-)

A friend tried that for kicks, throwing small chunks of oak and pine into the burn pot. The results was that he had to replace the bearings of the exhaust blower which was a nasty job.

In hindsight I should have installed a wod stove downstairs, just like we did upstairs. Less complicated, no misson-critical electronics and, therefore, more reliable.

It is definitely running because it continues to issue pulses for the auger motor, feeding the pellets into the burn pot.

A friend had replaced their double-oven electronics three times. When board #3 also croaked he got rid of the whole thing and obtained a steampunk oven. Which, of course, still works fine.

My cooking is real steampunk. It'll happen again in 30mins despite the rain. I'll steal some almond wood coals from our wood stove in the living room and dump them into the Weber kettle. It still has the snuffed out coals from yesterdays bread and chicken and sauce cooking and the glowing coals will reignite yesterday's coals within minutes. Then a tasty tritip will be cooked, along with some more bread plus cowboy beans in a cast iron skillet.

The old Weber is like my old Citroen was. Zero electronics, not even a lone diode. So it'll survive me some day.

Last week I repaired our 25 year old fridge/freezer. Aside from environmental reasons the main motivator was that I absolutely positively do not want a high-falutin digitally controlled new unit, which will inevitably fail and then possibly become irrepairable because they don't make the board anymore. The old Kenmore was easy, I replaced the mechanical defrost timer and the also mechanical thermostat .. done. In the wake of that I also gave it LED lighting so technically it now contains electronics but those aren't mission-critical.

Piezo and electronic igniters are OK, as long as you can still use a match. I have a bunch of the Zeitgeist matches in stock.

I replaced the thermostat on my 33yo fridge a couple of months ago.

The only thing I've had to do to my 32yo dishwasher is put Sugru around bits of the wire plate holders where the plastic had cracked and the wire had begun to corrode.

Due to the rotating mechanical sequencer, I can understand how that one is operating - unlike my parents' one which has LEDs indicating "on", "active" and "end". I've never been able to understand what the "on" LED signifies (and nobody has been able to tell me!), nor how long before it finishes the cycle.

In those days, diffusion from the surface was the doping mechanism; it is usually ion implant nowadays (the profiles are very different). Also, I'd expect digital electronics (with a noise margin) might be at variance with that result. 60's transistors often failed by low C-B breakdown voltage, and didn't have much margin there to begin with.

There's a 'remedy' in the power-on self test (POST) for many systems, which is a checksum. It wouldn't be a fix, just an 'uh-oh squad' fingerpointing exercise. Reprogramming or replacement is the best bet. My experience with older machines is, EPROMs can often last a long time (1986 MacPlus still boots, 1983 auto computer still runs it).

Oh, no geared clockworks on stoves have ever impressed me as reliable. I only once had a microwave's solid state clock/timer go bad (TTL with no bypass capacitors; to fix, I hand-soldered some in and thought evil things about 1980's Goldstar engineering).

We have a separate gas cooktop, which has electronic ignition and works perfectly after 11 years. (We re-did the kitchen 11 hears ago.)

Ditto for a wall-mounted double oven. The oven runs a separate fan to keep the electronics cool, and has also worked fine that long.

Dishwashers are the real horror for electronics--we've gone through three of them in that time.

Cheers

Phil Hobbs

A home near here was blown up from a gas leak. This was a concrete building, floors, walls and roof turned into a bunch of rubble. All the other houses around it were also concrete, so people in them were not injured and those buildings were not seriously damaged. A stick built house could literally be blown apart by such a gas leak. It all depends on how much leaks before a source of ignition is found.

I've had the same dishwasher for over 30 years without a failure other than a frozen valve when the heat went out. I've read about dishwashers that caught fire because of faulty crimp joints in the wiring. I think that was here actually.

I had a gas oven that used electronics as a thermostat, with the gas turned on and off, rather than up and down. If it failed to reignite after about three tries, it just gave up, without so much as a warning beep.

So one could come back after an hour and not only discover that the contents weren't cooked, one didn't even know how long it had been on for.

Also, why would one want a gas oven that requires electric power to operate so that it cannot be used during a power outage?

Sylvia.

Glad to hear it! I once worked at a place where the emergency stop button was "redesigned" by a mechanical engineer and an unauthorised electronics hack to fit the parts available at the time. It was to shutdown a 2kW 9000K argon plasma torch if something went wrong.

The result was that whereas the big red stop button was originally normally closed press to break (fails safe) it was swapped to normally open press to close. Big problem was the thing had not been plugged in to the wiring harness on the one that I was working on.

After that incident I paid a great deal of attention to safety interlocks particularly if bits of me were in the beam line or near to parts that would be at HT under normal operating conditions.

I wouldn't want that unless it could also be started with a match. In case of a power outage and because spare parts for that are eventually bound to become unobtanium.

As long as it issues a warning if that fan ever stalls. I prefer low-tech ovens such as this:

We have a dishwasher for over 20 years now where I was skeptical at purchase time. The sales guy assured me there were no electronics inside and he was right. While it has modern-style pushbuttons that look like digital controls they are like on the old gas guzzlers with push button transmission buttons. You press one and there is an assuring kerchunk happening behind the panel. Looks very repairable in case it ever goes.

That dishwasher was deeply discounted because people wanted high-falutin ones with LCD or at least VFD panels.

We had those for a while here in the US. When I was recently looking for a replacement stove (the old one having outlived its manufacturer by a few decades, and spares were lo longer available), one question is if one can use the stove without mains power. As you might imagine, there was one correct answer, and a multitude of wrong answers -- Next!

The Thermador I bought has two burners that require mains power, but the rest do not, but do require a manual lighter. The oven and broiler also don't work without mains power. But four stovetop burners suffices.

This was a recent change - some friends nearby also have a similar Thermador, and it is useless without mains power.

Joe Gwinn