On 12/12/21 2:50 PM, jlarkin@highlandsniptechnology.com wrote:> On Sat, 11 Dec 2021 11:51:11 -0800, Joerg <news@analogconsultants.com> > wrote: > >> Just repaired our fridge when, according to Murphy's law, the next >> appliance became shaky. Our pellet stove has twice refused to be turned >> off. Unfortunately, instead of analog it's all buttons that are operated >> via port pins of a micro controller. Pressing several of those >> willy-nilly made the on/off button work, at least long enough to turn it >> off. When the circuit board is cold the botton always works but not when >> warm after running the stove overnight. > > 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. >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. -- Regards, Joerg http://www.analogconsultants.com/
Bit rot in micro controllers?
Started by ●December 11, 2021
Reply by ●December 12, 20212021-12-12
Reply by ●December 12, 20212021-12-12
On Sun, 12 Dec 2021 15:24:23 -0800, Joerg <news@analogconsultants.com> wrote:>On 12/12/21 2:50 PM, jlarkin@highlandsniptechnology.com wrote: >> On Sat, 11 Dec 2021 11:51:11 -0800, Joerg <news@analogconsultants.com> >> wrote: >> >>> Just repaired our fridge when, according to Murphy's law, the next >>> appliance became shaky. Our pellet stove has twice refused to be turned >>> off. Unfortunately, instead of analog it's all buttons that are operated >>> via port pins of a micro controller. Pressing several of those >>> willy-nilly made the on/off button work, at least long enough to turn it >>> off. When the circuit board is cold the botton always works but not when >>> warm after running the stove overnight. >> >> 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. >> > >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 yam what I yam - Popeye
Reply by ●December 12, 20212021-12-12
On 12/12/21 23:24, Joerg wrote:> 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.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.
Reply by ●December 12, 20212021-12-12
On Sunday, December 12, 2021 at 8:02:25 AM UTC-8, Hul Tytus wrote:> In the 60's & 70's 20 years was mentioned as a life span for diffused > silicon. Somebody's diffusion rate.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.> > Can these things develop loss of flash memory (bit rot) this soon, after > > only two decades? Any remedy short or reprogramming or is it toast?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).
Reply by ●December 12, 20212021-12-12
On Sunday, December 12, 2021 at 2:50:47 PM UTC-8, jla...@highlandsniptechnology.com wrote:> 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.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).
Reply by ●December 12, 20212021-12-12
jlarkin@highlandsniptechnology.com wrote:> On Sat, 11 Dec 2021 11:51:11 -0800, Joerg <news@analogconsultants.com> > wrote: > >> Just repaired our fridge when, according to Murphy's law, the next >> appliance became shaky. Our pellet stove has twice refused to be turned >> off. Unfortunately, instead of analog it's all buttons that are operated >> via port pins of a micro controller. Pressing several of those >> willy-nilly made the on/off button work, at least long enough to turn it >> off. When the circuit board is cold the botton always works but not when >> warm after running the stove overnight. > > 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. > > >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 -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●December 12, 20212021-12-12
On Sunday, December 12, 2021 at 10:01:26 PM UTC-5, Phil Hobbs wrote:> jla...@highlandsniptechnology.com wrote: > > On Sat, 11 Dec 2021 11:51:11 -0800, Joerg <ne...@analogconsultants.com> > > wrote: > > > >> Just repaired our fridge when, according to Murphy's law, the next > >> appliance became shaky. Our pellet stove has twice refused to be turned > >> off. Unfortunately, instead of analog it's all buttons that are operated > >> via port pins of a micro controller. Pressing several of those > >> willy-nilly made the on/off button work, at least long enough to turn it > >> off. When the circuit board is cold the botton always works but not when > >> warm after running the stove overnight. > > > > 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. > > > > > > > We have a separate gas cooktop, which has electronic ignition and works > perfectly after 11 years. (We re-did the kitchen 11 hears ago.)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.> 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.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. -- Rick C. + Get 1,000 miles of free Supercharging + Tesla referral code - https://ts.la/richard11209
Reply by ●December 13, 20212021-12-13
On 13-Dec-21 2:01 pm, Phil Hobbs wrote:> jlarkin@highlandsniptechnology.com wrote: >> On Sat, 11 Dec 2021 11:51:11 -0800, Joerg <news@analogconsultants.com> >> wrote: >> >>> Just repaired our fridge when, according to Murphy's law, the next >>> appliance became shaky. Our pellet stove has twice refused to be turned >>> off. Unfortunately, instead of analog it's all buttons that are operated >>> via port pins of a micro controller. Pressing several of those >>> willy-nilly made the on/off button work, at least long enough to turn it >>> off. When the circuit board is cold the botton always works but not when >>> warm after running the stove overnight. >> >> 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. >> >> >> > 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 >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.
Reply by ●December 13, 20212021-12-13
On Monday, December 13, 2021 at 2:01:26 PM UTC+11, Phil Hobbs wrote:> jla...@highlandsniptechnology.com wrote: > > On Sat, 11 Dec 2021 11:51:11 -0800, Joerg <ne...@analogconsultants.com> > > wrote: > > > >> Just repaired our fridge when, according to Murphy's law, the next > >> appliance became shaky. Our pellet stove has twice refused to be turned > >> off. Unfortunately, instead of analog it's all buttons that are operated > >> via port pins of a micro controller. Pressing several of those > >> willy-nilly made the on/off button work, at least long enough to turn it > >> off. When the circuit board is cold the botton always works but not when > >> warm after running the stove overnight. > > > > 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. > > > > > > > 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.Our dishwasher is fine as far as the electronics go - we bought it with the flat when we bought the flat, about fifteen years ago - and it is still working fine. It's a Bosch SG14004/AU/07 and the plastic front panel that locates the the knobs and press buttons has lost enough plasticiser that it doesn't lock onto the metal door as originally intended. A certain amount of masking tape locks it place securely enough to keep everything engaged, so it's still working fine. I talked to Bosch (or at least their agent in Sydney about a replacement plastic moulding, but it is way too old for that to be an option. -- Bill Sloman, Sydney
Reply by ●December 13, 20212021-12-13
On 12/12/2021 23:06, Joerg wrote:> On 12/12/21 1:46 AM, Martin Brown wrote: >> On 11/12/2021 19:51, Joerg wrote: >>> Just repaired our fridge when, according to Murphy's law, the next >>> appliance became shaky. Our pellet stove has twice refused to be >>> turned off. Unfortunately, instead of analog it's all buttons that >>> are operated via port pins of a micro controller. Pressing several of >>> those willy-nilly made the on/off button work, at least long enough >>> to turn it off. When the circuit board is cold the botton always >>> works but not when warm after running the stove overnight. >>> >>> The micro controller is a Winbond W78E52BF-24 running on a 12MHz >>> crystal. It is based on what they call electrically erasable MTP-ROM >>> with which I assume they mean EEPROM. Date code is 2001 and that is >>> also when we had that pellet stove installed. >>> >>> Can these things develop loss of flash memory (bit rot) this soon, >>> after only two decades? Any remedy short or reprogramming or is it >>> toast? >> >> My instinct would be there is a failing electrolytic capacitor >> somewhere that is allowing the CPU to see glitches that blind it to >> the on/off button. ... > > > 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. > > >> ... Some polling algorithms are a bit stupid so another button stuck >> down might also have the same effect. You might have hoped that there >> would be a failsafe emergency stop button on something that makes fire! >> >> I never trust CPUs for safety interlocks! There is good reason. >> > > Luckily this stove has hardware safety interlocks for vacuum and proof > of fire which the CPU cannot override.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. -- Regards, Martin Brown
