[benreyn]

touch pad goes dead. tried turning off power for a few minutes to no avail. no error codes. pulling and reinserting ribbon connector fixes it for a week, then it goes out again. sears replaced board and touch pad a few years ago. would have cost $800-900, but it was just out of warranty, so they comped it. how can i determine which part to replace?

[denman]

Could be either but more likely the touch-pad. I am assuming only the pad is totally, dead everything else looks normal.
I looked at the picture of the pad and did not see any active components so am assuming it is just switches.

You say turning power off by itself does not reset the control.
I assume that when you disconnect/reconnect the pad power is also off
Since you do not have power applied you are not actively resetting the board from the pad so that's why I lean toward the pad.
The only caveat here would be time. Some boards take a while to reset (capacitors have to discharge). If you have not done it turn the power off for the amount of time it took to disconnect/reconnect the pad.
Does it now reset? If yes then probably the control board is shot.

The most common touch pad problems are the edge connectors and the ribbon cables itself
Best way to clean cable's edge connector is with a pencil eraser (do not use ink type)
Clean the connector on the board with electronic contact cleaner or isopropyl alcohol and a toothbrush.

The conductors in the cable can also be a problem
Looks like the cable is see through which is good.
Get a magnifying glass and inspect it for hairline cracks in the conductors.
Pay special attention to the conductors on the outside edge, these are usually the ones that are common to all switches or it could be one that is wider than the rest.
Bend it a little as you inspect it, this sometimes will make a crack visible.
If you find a crack, these cables are repairable and may be worth a try.

Could also check the conductors for continuity with an ohm meter but you would have to be able to open up the pad to do this. Some you can, some you can't.
Again you have to bend the cable along it's length for the open to show up.

I am a little concerned that Sears replaced both at the same time.
It may indicate that if one part goes bad it can take out the other part.
This should not happen on a decently designed system but without actual board schematics I cannot tell.

[benreyn]

all buttons on keypad are dead. clock does continue to work, which makes me think it's not the oven/clock control board. i have turned off power for the day, so will see if that resets it. that however is not an option when you're ready to cook. thanks for the help.

[benreyn]

with power off for 8 hrs, pad reset and worked once. 30 mins later it was dead again. pulling and replacing ribbon connector, which i now have down to 3 minutes, worked again.

[denman]

I am at a loss without board schematics

It could be the control board interogates the touch panel every so often. If it sees a shorted switch it decides there is an error and locks up the board.

I would try the touch panel first. You may be able to find a supplier that will let you return it if it does not fix the problem. Most places will not let you return electronic parts but I personally do not cobsider this an electronic part, after all it looks like is just a bunch of bubble switches with no active components on it.