A rant on circuit boards.

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Greg_Lewis
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A rant on circuit boards.

Post by Greg_Lewis »

I just have to complain. We had a power outage last week. When the power came back on our cooktop would not work. Nothing. Research revealed that there are two, not one but two, circuit boards inside. And, of course, the surge when the power came back on fried the main control board. And, of course, the board is $300 and out of stock at every site I looked at on line. With luck we’ll get one sometime in the middle of May.

My parents had an electric stove and it didn’t have a circuit board. I had a Model A Ford, a 1953 Dodge pickup, two VW Beetles, and 1963 F100, and they all ran fine without circuit boards.

My parents refrigerator and washing machine didn’t have circuit boards, and we inherited them and ran them for perhaps ten years more. Their dishwasher didn’t have a circuit board. My lathe and mill do not have circuit boards. My binoculars to not have a circuit board nor does my phillips screwdriver or my ball peen hammer.

What is it with circuit boards?

I may have complained during the Covid lockdown about my refrigerator dying because of a circuit board. It was less than 10 years old, but the board was discontinued by the manufacturer. The cost of the board from other sources was such that it was wiser just to replace the whole refrigerator than to replace the board. Never mind that the mechanical elements were in perfect running condition.

My truck has circuit boards. Two went bad at the same time. The dealer price for the main one was $900. (I was lucky to get a used one for $200.) The other board “rebuilt” was $250. In the days of carburetors and breaker point ignition, if you had gas, compression and spark, you could get it to run. Not anymore.

A mechanic I knew said that on the BMW, every single part is somehow connected to a circuit board. I suspect that’s true for all modern cars. The wiring loom for my Model A had, I think, 12 wires for the entire car. Same with the ’53 Dodge pickup. The wiring for just the AM/FM radio in my truck has 16 wires. For an AM/FM radio??

And what Really Fries My Cookies is that when these circuit boards go bad, all that’s bad is a little capacitor or resistor that cost the manufacture less than a cent but which will cost you hundreds of dollars or more. And that's if you're lucky enough to find a replacement.

Take a look at the photos below of the board out of my stove top. Why does a stove need a board of such complexity? And if you look at the last photo, you’ll see the burned spots where it looks like a diode and some resistors fried. I couldn’t get a photo of where on the other side a couple of capacitors also looked burned. Total value of those parts, fifty cents retail?

Nuts!

The bottom of the main control board. How could a stove need such complexity?
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Top side of board. Did Alan Shepard's Mercury space capsule have this much circuitry?
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The fried section of the board. Looks like a diode and some resistors, plus two capacitors on the other side.
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Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
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Steggy
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Re: A rant on circuit boards.

Post by Steggy »

What brand of stove is this?
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Greg_Lewis
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Re: A rant on circuit boards.

Post by Greg_Lewis »

GE. But the board seems to be used in several brands. I have found that other appliance parts are common to more than one brand.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
jcfx
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Re: A rant on circuit boards.

Post by jcfx »

Is your electric stove induction or those coils that I can't remember the name of ?
Has it a timer, a clock, timed oven on/off , alarm ?
That's where that circuit board comes in unfortunately, modern conveniences via electronics.
:)
Don't get me started with refridgerators, TV's etc that need to be connected to the web...

Fwiw, most ranges and fridges are made by one or two companies, just branded different.
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liveaboard
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Re: A rant on circuit boards.

Post by liveaboard »

I installed an AC unit that had a wonderfully complex electronic control, that fried in a similar way after some years. The company is no longer trading, used control without guarantee cost $500.

Now the AC unit runs through a bimetal thermostat and a relay. Works just fine.
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Greg_Lewis
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Re: A rant on circuit boards.

Post by Greg_Lewis »

The stove is just a plain vanilla electric thing. No clocks, timers, wifi, or satellite control. Just coils that heat through the glass top. It does have touch switches, so I understand the need for some sort of electronics to make that work, but IMHO, this is ridiculous. It may be that this board, being used in other devices, has components that are not used for this stove. But regardless, you'd think they'd design it to handle a power surge without blowing. There is a fuse on the board that is intact. Why did it not protect the board? (Answer: They make money off replacement boards and service calls.)
Greg Lewis, Prop.
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Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
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Steggy
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Re: A rant on circuit boards.

Post by Steggy »

Greg_Lewis wrote: Thu Mar 30, 2023 5:01 amThere is a fuse on the board that is intact. Why did it not protect the board? (Answer: They make money off replacement boards and service calls.)
Fuses are very slow. The time required to fatally damage most solid state parts is a fraction of the time required to heat the fuse’s element to where it will melt. There is no foolproof method of preventing a lightning-induced line transient from damaging solid state parts, short of interposing a ferroresonant transformer in between the power source and the load.
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Greg_Lewis
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Re: A rant on circuit boards.

Post by Greg_Lewis »

Thanks, Steggy. We learned some time ago that when we have a power failure to unplug the computers. And we just added surge protectors. Now we will just shut off the breakers to everything but the living room incandescent bulbs, and when the power comes on, we'll turn the breakers back on.

I just filled out a claim form for the power company and it says that they depreciate the value of anything they reimburse for, so considering the age of this stove top (14 years) I expect to get perhaps $2.37 if I'm lucky. PG&E does not have a good record here in California.
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Charles T. McCullough
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Re: A rant on circuit boards.

Post by Charles T. McCullough »

Switching off the breakers might not do much good. A bolt of lightning that induces a current in the power lines has possibly jumped 5 to 20 or 30 miles, so that gap in the circuit breaker is a very minor annoyance to the voltage spike coming in. It'll jump that gap with a pretty electric blue arc and happily travel down the house wires to the sockets, into the power cord of the Computer, Stove, Furnace, Radio, TV, Microwave, Electric Toothbrush, etc. It may even jump right across the gap in the on/off switch (even if the device happens to actually have a real circuit interrupting mechanical switch, which few things do these days) to play on the circuit boards and semiconductors thereon.
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My mother-in-law got tired of adjusting the rabbit ear antennas when she changed channels on her TV, so she got several TVs and tuned each to a different channel with the antenna on each adjusted for the best reception on that channel, When she decided to watch a different program, she didn't change channels, she changed TVs! One night she was watching one channel, when a storm induced power surge permanently turned that TV off, turned on two others, one permanently and the other was still able to turn on and off manually, but not with the remote!
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High voltage is just like computers in general... they both are neither smart nor dumb... they are just plain MEAN! At least a computer can be rebooted when it goes nutty, but high voltage does what it wants, when it wants, how it wants, regardless of what we do to try to control it.
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It can come in via your Cable TV, or internet connection. Joyously wending its way through the modem and router to any hardwired devices (at least it cannot come into your computer if it (or other IoT) are on WiFi, But the WiFi router might not be a WiFi router anymore after the spike burrows through the silicon chips creating holes for the magic smoke to get out.
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Steggy
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Re: A rant on circuit boards.

Post by Steggy »

Greg_Lewis wrote: Thu Mar 30, 2023 12:58 pmThanks, Steggy. We learned some time ago that when we have a power failure to unplug the computers. Now we will just shut off the breakers to everything but the living room incandescent bulbs, and when the power comes on, we'll turn the breakers back on.
All the computer hardware around here is powered from a humongous ferroresonant UPS, so that stuff can stay powered during a thunderstorm.

I just filled out a claim form for the power company and it says that they depreciate the value of anything they reimburse for, so considering the age of this stove top (14 years) I expect to get perhaps $2.37 if I'm lucky.
Your homeowner’s insurance may cover some of it.


PG&E does not have a good record here in California.
That’s not entirely their fault.

PG&E appeared in disguise in a novel from the 1970s that clearly was meant to portray the California power industry to be a victim of bad environmental politics. Subsequent events illustrated that while the novel was fiction, its principal premise was not.

PG&E has had a long history of having generating station projects blocked by politicians backed by radical environmentalists. Generating capacity was stagnant for years, while at the same time, the population exploded. Inevitably, the spiraling load has led to planned (rolling) brownouts and blackouts, as well as unannounced failures due to the combination of heavy grid loading and hot weather.

I laugh when I read of California’s push to replace ICE vehicles with voltswagons. The people pushing that nonsense haven’t the foggiest notion of what it would take to supply juice to all those hungry batteries. The generating and distribution capacity isn’t there, and is unlikely to materialize for at least 15 to 20 years...if ever.
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Greg_Lewis
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Re: A rant on circuit boards.

Post by Greg_Lewis »

Thanks, Charles. This was a surge when the power came back on, not a lightening strike. I love the story about your m.i.l. But you make a good point that many devices today are what some call alligators. They never stop eating. Even when the power is allegedly off, they are still drawing current. Never mind the stuff we never turn off — our router, computers and printer stay on all the time in addition to the fridge and freezer and the old-fashioned cordless phone set for the land line (Gasp!? Yes, we still have a land line.)

Thanks, Steggy, but the board is just under $300. My deductible is more than that.

By the way, folks, I apologize for the comment about PGE. That brings politics into the discussion and I think we're better off to leave that to other forums.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
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Bill Shields
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Re: A rant on circuit boards.

Post by Bill Shields »

If you have not already done so, suggest that you check your ground rod continuity to power company ground

Something in the back of my mind says that if it is over 25 ohms, surge protectors are useless because they have no place to dump the surge.

Good electricians and electrical inspectors have a clamp on meter to check this.

We had an entire community out our way and everyone was having problems with surges blowing up things, even with surge protectors installed

seems that the neighborhood had been built on a land fill and none of the standard ground rods were worth a crap.

I helped a friend (electrician) check out several houses, and in one case we ended up driving an 80' ground rod to get a good continuity check.

Moral of story is that just because you have a ground rod dies not mean it is working as intended.
Too many things going on to bother listing them.
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