Unplug fridg. for several minutes, then plug in, module might now work. If not, I would replace the control module.
The new module must be programed by using the info on the model # sticker. Just follow the directions you receive with the part.

Thanks for the thoughts.

After I posted yesterdays question, I was able to get the module to respond in a program mode (even though still just showing dashes in normal mode) and I went through some diagnostic tests and everything (compressor, fan, etc.) looked fine.

After going through the tests, the display appeared to work, so I left it on for the morning. It cooled to the right temperatures within a couple of hours, but then stopped again, just showing the dashes on the display. This time, however, it was not iced up as it was before. This pretty much confirmed to me that the problem was the control module, however, I decided to test the defrost heater and thermostat (mostly because I already had access and they are both cheaper than the module).

Defrost heat element had continuity but the defrost thermostat read 53k ohms (far from infinite) when warm and 45 ohms (somewhat far from 0) when cold. Everything I have read implies that this should be infinite at room temp and 0 when cold. Are these numbers within acceptable range, or is it possible that this is my problem and the dashes on the control module are some kind of diagnostic indication?

more thoughts?

Thanks for the advice.

After fussing with the control board and going through the diognostics process again, it seemed to come back alive and functioned appropriately for a day and a half, but this morning was back to the dashes on the board (although still fully cold). After going through a forced defrost and the diognostic process again, the display is back on and apparently working (at least for now). I don't suppose the display shows dashes when the unit is in a defrost mode?

I'm going to replace the thermostat like you suggest (still pondering the control board, maybe wait and see if the thermostat fixes the problem?).

Do you know anything about the replacement thermostat kit for this model made by whirlpool? I note that the replacement part available on this site is made by whirlpool, but I had the impression that the replacement kit was more than just the thermostat. However, I have not been able to locate the original reference to it that I saw the other day.

P.S.

I ordered the defrost thermostat, and reset the refrigerator by putting it into program mode and then going through the diagnostic tests. It has now been running fine for a week.

After all the above and several days to consider, I now have a working theory of what happened that I share here in hopes that it will be useful for others with this or a similar problem.

I think the dashes on the control module are a diagnostic indication that something is wrong with the system, rather than an indication of controller failure. (Maybe an indication of sensor failure?)

I think the unit frosted up and shut down due to being overworked because of a buildup of dust and such on the condenser (heat exchanger) coils (outside on the bottom of the unit.)

I believe that my initial attempts to reset it were only partially successful because I was still stumbling through the diagnostic procedures and/or had not yet cleaned the condenser coils.

Once the condenser coils were cleaned and the unit re-started, it has run fine for several days now.

I'm still fairly suspicious of the defrost thermostat. The warm reading on the new one is 56k ohms (far from infinite, and not significantly different than the 53k reading on the old one). The cold reading on the new one, however, is 0.5 ohms, which does seem considerably different than the 45 ohms of the old one, but still a pretty small number.

At this point, I really don't think I need a new controller, rather just to clean the condenser coils more frequently. Jury is still out on the defrost thermostat. Since we are not traveling for a while (little risk of freezing up while we are gone for an extended period), I'll leave it alone for a while and see what happens. If it freezes up again, I'll replace it. (and update this post)

Again, I post this for what it may be worth to other wandering souls searching for appliance repair inspiration.

Thank you, that insight is particularly helpful for me.

So it seems that the defrost thermostat does need to be replaced sooner rather than later, as it is not allowing enough current to the defrost heater element to allow it to work properly.

Accordingly, I'll replace the defrost thermostat with the new one this evening, UNLESS:

Do you (or anyone else) know anything about a replacement thermostat kit for this model made by Whirlpool that I mentioned previously? I note that the replacement part I purchased (from this site) is made by Whirlpool, but I had the impression that the replacement kit was more than just the thermostat itself, and somehow addressed what is apparently a design weakness with this system. However, I have still not been able to locate the original reference to it that I saw the other day, even though I believe it was on another thread on this site.

Also, is there a tech sheet available for my model (Amana Model AFB2534FES)? The one I am using (from another thread on this site) is apparently from a model ending in deb3 rather than FES. It is close enough to allow me to muddle through the programming and diagnostics (for which I am very grateful), but I would feel better about using more precise information. For instance, my unit has a diagnostic test 9 that is not described in the tech sheet that I have, and I'm seriously curious about what it is for.

At any rate, thank you for the advice and insights, and I hope my write-up can be useful for others.