Saturday, December 09, 2006

Replacing a timer: General Electric WB19X5249 in a JBP26G range

Some months ago, the mechanical timer on our GE range started buzzing. Sometimes we could make it stop by delicately adjusting it; other times it would decide you were trying to set it for 59 minutes and 15 seconds... and would tell you about it later. Not to worry, I said; let me stick a toothpick into the buzzer. This (top view) is not the recommended way to fix it:
timer fixed by toothpicks
This fix means you can't use the timer on the stove, but that's OK; a timer costs $9.95 and you can put it on the dining table or something. Well, that worked OK for a while, and then I couldn't get the clock to do anything at all. This was mostly OK, until we switched from Daylight Savings to Standard Time; I pulled the circuit breaker, turning the stove (and its clock) off. An hour later, I turned it back on.

Then last week, one of the controls broke. When my wife turned the front burner on WARM or LOW, the element got real hot real fast (it glowed red).

I suppose I could have just written "HI" everywhere on the knob that wasn't "OFF", but there were two problems with it — first, I didn't think of it until now, and second, it wouldn't have gone over very well. She called, they had the parts in stock, so off we went. The new control for that front right burner took a little guesswork, but basically it works now.

STOP! Before going any further, UNPLUG the range! As one of my wiring books says, Think! Stay alive!

The timer was a little more complicated. First of all, you can't buy those mechanical timers any more. What you get is one of those new-fangled electronic digital thingies that looks like this:

So there's one thing you should definitely do, even before you leave the store. First, let me explain that whereas the old mechanical timer had shafts sticking out of it (and "female" knobs that fit onto them), the new timer has holes. But fear not; they give you these knobs that are, umm, "male". Here is a close-up of one:

Find three of these guys, insert them into the appropriate places in the timer's front panel, and give each one a gentle push. Make sure the switches give you a little tactile feedback. On the first timer I got, the "UP" and "DOWN" ones worked OK, but the "MODE" one felt like it was just a dummy button. The problem was that the circuit board was warped, so the shaft didn't quite reach the button (...biting my tongue as I write this...) mounted on the circuit board. The switch, in other words, was too far away from the front of the timer unit, making activation impossible.

I didn't find out about all this until I had removed the old timer, inserted the new one (a LONG process), wired it up, etc. So save yourself the trouble — make sure the timer and the knobs actually work together.

OK, now that you've got the timer, how do you replace the old one? You have to remove the front panel from the range. Pull off the oven control knobs (one on each side of the timer). You'll need to remove one screw from each control to release the front panel. Here's the right-hand one (oven temp):

Notice how the bottom screw used to hold the front panel onto something, but the top screw can be accessed regardless whether the front panel is on or not? So remove the bottom screw here, and also the corresponding screw on the OVEN SET switch (to the left of the timer).

The next thing you have to do is remove these nasty "TORX" things that hold the ends of the front panel. There is one on each end cap and one at each end of the top. I don't have a regular TORX tool, but about 25 years ago, my dad bought me a set of screwdriver (etc) blades for my electric drill. Here is a picture of the screwdriver blade kit:

It's a very nice kit. The tool of interest is the leftmost one in that photo, so I guess the two blades you need are the TORX T15 and T20. Anyway, there are two pictures showing the end of the top of the stove, and the end cap:

The second one shows the TORX tool in the screw in the top of the stove. When you do this, watch out for the off-white plastic plugs. These guys hold the end-caps onto the top-rear flange of the front panel, and they have a tendency to fall out and roll under something.

Anyway, after you get all 4 TORX "screws" removed, you'll be able to drop the front panel.

You've disconnected the power already, right?

Oh! You need to get the back panel off, too, so you can get at the wiring and stuff. You want a 1/4" nutdriver for these. The far right (viewed from behind the stove) screw need only be loosened; you don't need to completely remove it. You do have to remove 4–5 others, though; then you can slide the top section of that rear panel downward and to the left, then off that right-hand screw.

Anyway, if you're more observant than I am, you'll probably notice that there is some mounting hardware in the box:

Probably you'll want to take those brackets, find four screws to attach them to the timer like this:

and mount it onto the stove like this:

But don't do it, because you won't be able to put the front panel (in this picture, lying on the cooktop surface) back on! This was a design gaffe on GE's part, in my not-so-humble opinion.

So here is what you should do instead. Take a screwdriver with a sharp blade, and, standing behind the stove, hold the timer carefully so you can see where you have to notch the sheet metal. Using the screwdriver, score the sheet metal where notches will be needed. A triangular file or (what I used) a single cut bastard mill file will do it. Here's the thing: even without the brackets, the timer won't slide backward and fall out the back. In fact, you won't even be able to put the front panel back on. You have to cut some notches in the vertical pieces of sheet metal, so that the timer can slide part-way back. That's what the file is for.

OK, here's a picture taken from the back of the stove, after I filed a couple of notches.

You can see the places where I scored the sheet metal, but the notches aren't very clearly visible. Here's a photo taken from the front; notches are more clearly visible here.

Note also the lack of mounting hardware.

You have to do that on both the left and the right. Installation of the front panel is the reverse of removal. Make sure the timer doesn't move around while you're replacing the front panel. Start the two (larger/longer) TORX screws atop the front panel, but don't tighten them yet. Double-check the position of the timer. Start (but don't tighten) the two shorter TORX screws to hold the end-caps to either side of the range. Now install the two screws that you took out earlier, one on each oven control knob, to hold the front panel on. You can tighten these. Then tighten the four TORX screws. Install the wiring. Plug the range back in and do a sanity-check on the clock.

NOTE: The instruction sheet is your friend!

Put the back panel back on. You probably moved the stove some in order to get at the back panel; now would be a great time to run the vacuum cleaner on the parts of the floor newly exposed, if you haven't already done that.

Return the stove to its normal working position. You're allowed to feel smug, but don't reveal that feeling to your spouse; there's no profit in that.

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