So I go ahead and get out some pecans from the freezer downstairs, along with the IBM 1390 keyboard from the pile of stuff, because I wanted to test it with El-Hazard.
Ended up chatting with Og for a few minutes, about go-karty goodness and other things, and then logged off there. Did a little WoW, then got after the brownies. Everything went well and I put them in to bake. About eighteen minutes later, Mrs. Fungus commented, "The brownies smell good!"
Then the smoke alarm went off.
Sighing, I got up to go have a gander, because the smoke alarm usually does not go off while baking brownies--but then I lined the pan with wax paper, and who knows? As I stepped out of the computer room I could smell the waxed paper, then as I got to the kitchen I could see the smoke roiling out of the stove.
Open the oven, more smoke...why is the broil element on, I wondered? And it was full on, glowing bright orange. Pulled the brownies out--the top of them were charred black--and pulled the battery from the smoke alarm to shut it up. Went to the computer room and said to Mrs. Fungus, "The brownies are not fine," then returned to the kitchen to try to figure out WTF was going on.
Mrs. Fungus came out then, saw the brownies, and said something unladylike as I tried to turn off the oven. It would not shut off. I pressed the "off" button and the boil element stayed cherry red. Finally I decided I'd have to pull the power cord, so I started dragging the stove out.
She didn't want me to do that--I'm not sure why, probably she was afraid of a shock hazard, but I couldn't let the damn thing continue to run away like that, so I yanked the cord. Deprived of power, naturally the thing stopped.
Waited a few minutes while we swept up the stuff from behind/under the stove (why not?) then plugged it in again, and the broiler element heated right back up, so I unplugged it.
Fortunately, on the back of the stove there is, in a plastic pouch, a complete circuit diagram. "This'll help me diagnose the problem--" I began, but Mrs. Fungus interrupted me.
"You're going to diagnose it?" She asked skeptically.
I just looked at her.
She then attempted to backpedal, but I know better. I know when I've been insulted! I know when I've been insulted!!
...anyway my guess is that something went wrong with a relay or something like that. Probably the control board for the oven is a single part number and won't cost much more than a jillion dollars, and that should take care of it. The circuit diagram for the thing is dead simple, anyway. Certainly it's a lot simpler than the avionics for which I used to write detailed circuit theories.
And we're without a stove until I fix this, because I can't plug the damned thing in. *sigh*
ADDENDUM: So here's what I've found out since the last post:
1) A new control board for this thing is $250. That's a bit cheaper than a new stove at $350, but I also found this place which will rebuild the control board for $136, which is doable.
2) Considering that every other function of the stove works correctly, the fault is probably due to a failed relay. If I could find that relay I could try replacing just that part first to see if that cures the issue. That would cost a hell of a lot less than $136.
3) This is, apparently, a common problem with this vintage of Kenmore stove, and replacing or repairing the control board is usually the remedy for it.
4) I could remove the broil element in the meantime and have, at least, a functioning stovetop. The oven might work for baking, or might not. But if I send in the control module, we won't be doing any cooking until it comes back because that one board runs the whole works. *sigh*
5) I am lucky to have caught this before the thermal protector opened, though it looks like the thermal protector only stays open as long as the stove sees power and it resets itself when unplugged for more than about a minute.
Still, all told, this is not how I wanted to end my weekend. *sigh*
SECOND ADDENDUM: Turns out the brownies are perfectly edible as long as you scrape off the top 1/16" of charcoal. All is not lost.
THIRD ADDENDUM: So I dug out my multimeter and some basic hand tools and had a gander at the thing. Checked for continuity across the oven element terminals and it was there. Tried to unplug the elements but couldn't--that plug has been there for about 13 years--and then decided to take the whole board out and then figure out why I couldn't get the plug out. That done, I checked the terminals on the board for continuity and found none; similarly there was no continuity across the terminals on the plug, meaning that the elements are not shorted. Put the board back in, reinstalled all connectors, no continuity. Plugged stove in to power, and the broil element stayed cold. Unplugged stove.
On the control board, the relays that switch the oven elements on and off are RT334024F, and I found them here for the stunning price of $3.54 each. These are exact replacements, right down to the brand name, and since I know my way around a soldering iron I expect I could install the new relays in about fifteen minutes. If the relays are the problem--which I expect is the case--then I'd save myself about $129 or so. Taking the board off probably rattled loose the stuck relay, and I'd wager if I tried to bake something it would stick right back on again, which is why I'm not plugging the stove back in until I've fixed it.
But that won't be until I can be home for a few days, to keep an eye on the thing.