Buttons on control panel don't work on left. Right works

also,there might be a problem with your cicuit breakers,it sounds like you are only getting half of the 220 volts.

Sometimes the timer display fades but still working in background, if all dead now then probably means you need new timer as ovens shouldn't work if clocks not set to manual mode.
Try turning oven on then messing with buttons, usually the 2 left buttons and one far right should do trick.. push 2 left first, keeping them pressed push far right!

warmest regards
Richard The Repairman

TRY THIS... If the buttons are "stuck", the glass panel may have shifted to the right or left causing the holes in the glass (through which the button protrude) to rub against the glass. VERY CARFULLY try to shift the glass so the buttons are centered in the holes.

I'm not sure if you have removed the trim on the right and left front. so if you have not then open the bottom oven door and in the lower right and left corner near the hing should be a screw, remove them and pull down on the trim pice and now this will revial a screw at the top right of the control pannel on the left and right , now remove them screws and make sure power is turned off at the fuse box and lift on the control pannel. if this does not work you will need to remove the unit.

(I'm providing a late, modern response for people like me who land here in 2022+)
I had the same problem. Gradually it got worse until only Bake ' Cancel work. Sometimes the problem is due to bad ribbon cable connections; sadly, with this oven, the issue is the membrane buttons having failed. It's frustrating, because this has happened with every version of this model that I have seen. Add to this that the membrane buttons are behind a sealed panel that you can't access without breaking it, and you'll quickly learn that you need to buy the replacement part. 5765M483-60 is the matching control unit, but make sure with the vendor that it is the right size for your unit first; it's expensive. It's also now out of stock and is a 2-3 month special order at most vendors. The replacement is tedious, but simple and approachable for a first time DIY'er. At this point, I'd rather buy a new replacement oven instead, but finding 27" models is difficult as most are 30" now, which won't fit my cabinetry - thus I bit the bullet and bought the replacement control unit. Oven came with the house on purchase; former owner told me she had already done the same repair once before; so that means this problem will keep recurring.

It is the whole front face w/ the buttons. My whole neigborhood has these ovens (same builder, same ovens) and this part lasts about 2-4 years. The part is about $165. You can see it on Home Depot's appliance repair site. It looks like there is nothing electronic, but there is, and it's busted. It is really easy to replace:
1. Turn off the breaker at your house's breaker panel.
2. Verify there is no power to the oven.
3. Open the oven door. Look on the right and left side of the oven. There should be 4-6 screws going from vertical trim pieces of the oven into your cabinets. Your builder may have also put screws from the bottom trim of the oven into your cabinets. Mine did not. Remove these screws.
4. After that, your oven should slide forward out of the cabinet. Pull it about 6 inches out.
5. There are two screws (1/4 inch hex headed screws) holding the front panel to the oven. Remove those.
6.Slide the front panel off.
7. Remove the computer ribbon looking wire from the back of the control panel. It's a strange connection - it should come out effortlessly when done right. The little grey connection that surrounds the wire's entry point stays on the panel, but a wedge is jammed between the grey surround and the wire. You pull the wedge out and the wire comes out...easier than my credit card out of my wallet.
8. Remove the four screws (again, 1/4 inch hex headed screws) connecting the thick, double layered circuit board and clock display from the metal face.
9. The metal face is what you need to replace. Pasted onto the front of the metal face is a super thin button panel, and that's the part that died, and will die again, and again, and again...
email me for pics [email protected]

It is the whole front face w/ the buttons. My whole neigborhood has these ovens (same builder, same ovens) and this part lasts about 2-4 years. The part is about $165. You can see it on Home Depot's appliance repair site. It looks like there is nothing electronic, but there is, and it's busted. It is really easy to replace:
1. Turn off the breaker at your house's breaker panel.
2. Verify there is no power to the oven.
3. Open the oven door. Look on the right and left side of the oven. There should be 4-6 screws going from vertical trim pieces of the oven into your cabinets. Your builder may have also put screws from the bottom trim of the oven into your cabinets. Mine did not. Remove these screws.
4. After that, your oven should slide forward out of the cabinet. Pull it about 6 inches out.
5. There are two screws (1/4 inch hex headed screws) holding the front panel to the oven. Remove those.
6.Slide the front panel off.
7. Remove the computer ribbon looking wire from the back of the control panel. It's a strange connection - it should come out effortlessly when done right. The little grey connection that surrounds the wire's entry point stays on the panel, but a wedge is jammed between the grey surround and the wire. You pull the wedge out and the wire comes out...easier than my credit card out of my wallet.
8. Remove the four screws (again, 1/4 inch hex headed screws) connecting the thick, double layered circuit board and clock display from the metal face.
9. The metal face is what you need to replace. Pasted onto the front of the metal face is a super thin button panel, and that's the part that died, and will die again, and again, and again...
Email me for some pictures:
[email protected]

Try this link
http://www.fixya.com/howto/h155060-dreaded_f7_error

No, it's the first 2 buttons on the left pushed together as well as the + or - to set the right time

User manuals are hard to find.
The problem I had was setting the clock on a single Diplomat oven, with no clock button. Here's my solution :

DIPLOMAT OVEN OPERATING INSTRUCTIONS
The Diplomat single oven is controlled by two knobs and a set of buttons along the middle of the control panel.
The left knob sets the temperature of the oven, while the right knob selects the function to be performed, e.g. fan oven, grill, etc.
The buttons along the middle set the cooker clock, the start and end times of cooking, and the “+” and “-“ buttons will increase or decrease the time shown on the cooker’s clock.
PLEASE NOTE THAT THE OVEN WILL NOT OPERATE UNTIL THE CLOCK IS SET.
If there is any interruption to the power supply (including manually switching off at the main switch) the oven will not operate until the clock is reset.
Here’s how to set the clock:
First press simultaneously the first two buttons to the left of the control panel. They are marked as a Bell symbol (Alarm) , and a steaming Cooking Pot (Start of Cooking Time). Then immediately press the plus “+” or minus “-“ buttons to increase or decrease the time displayed. When the desired time has been reached, leave it for a few seconds, and it will remain set at this time. Any further changes to the displayed time will require this procedure to be repeated.
Hope this helps!