Door switch has 2 wires.1black 1yellow. both disconnected. which goes where?

The "other tech" needs to fix his mistake...

BEFORE DOING ANYTHING DISCONNECT OVEN FROM POWER. I do NOT recommend doing repair by yourself, if you NOT are really very familiar with electric repair, or have at least basic training in electric device repair and maintenance.
"When door is opened display goes dark. When door shuts display lights all characters and then says "touch clock"."
Obviously, by opening door, oven gets disconnected form power line.
This is mostly caused by loose connections on wiring socket, and can be anywhere inside. Check security micro switch on door latch. This switch normally disables only running the oven when door is open, for security reasons. In your case, it seems that opening door disconnects oven from input power. Sometimes the switch is loose, or wires are not firmly pushed in the socket. If the power line wiring is loose, and by opening door looses contact with socket, it can touch metal housing inside, cause short, electric shock, serious even mortal injury and fire. This is dangerous high voltage switch, and to access it one must open oven from the back and take off the cover. I do not recommend doing it by your self.
Rem: Replacement micro switch is couple dollars.

Possible that the door switch could be damaged. You can remove the front panel to check this out after disconnection the power.
If there is an alignment or a connection issue it can be reset. If not replace the limit switch.

This is a malfunction and must be checked to confirm if the microwave itself is working when the door is open which is dangerous. The reason can be due to a short in the door lock switch or a mis-alignment of the door switch. Also a malfunction of the main board, relay cannot be ruled out.Remove power and close the door with a gentle force , few times so as to disengage any lock switch defect. now try if the fan cuts off or else it is best to take opinion as you will need to disconnect the HT section to check this fault to prevent any stray microwave.

It may have tripped a high limit switch and less likely but possible it blew the fuse. A fuse blows due to an increase in amperage or a short. There is the possibility it melted components such as the door switches or a wire due to heating the cavity. Door switches pop fuses when shorted or the door doesn't engage them properly.
As most microwaves other than Panasonics contain capacitors you must be very cautious even when unplugged to avoid shock. 2100-4000 volt capacitor on the high side.
So where to begin is unplug the unit. Attach a wire to something grounded to bare metal on the machine. Open it. Look for burnt wires or components without touching anything. Discharge the capacitor using an insulated screw driver or tool (short the leads). Test the fuse using ohms Check the high limits (black disks the size of a penny) by testing across them using ohms. If the fuse is blown check out the door switches, some are closed with the door shut and others are the opposite. So test each switch in both door positions. Test the light wires to ground. Should read open. Test ohms on the whipper motor and fan and to ground as well. Reads measurable over the motor leads and open to ground. Test the capacitor using uF and compare to rating on the capacitor (be sure its discharged). Disconnect the magnetron. Test each lead to ground. It should be open. Its highly unlikely its the transformer or a computer board so i wont go into detail about testing those components.

2 things come to mind, 1)check the door limit switches. also make sure the switches are switching at the same time. Or very possible to board is faulty. All the signals and commands come from the board. Electronic control goes faulty and things wont switcjh off.

When door is closed, it activates 2 or 3 door limit switches depending on design .By bumping door hard, one of the limits are disrupted. that switches off the micro.(you are lucky by default because if wrong limit is switched accidently there could be a very loud bang.).
Pull plug out and remove cover. look for limit switches situated near door latch. Try and adjust limits to make a better contact on the door latches. Please note voltages very high on power side even though switched off. Just work at the door area.

if unit runs with door open then one of the door switch is stuck closed.there are 2 door switches and they could be assesed by removing the control panel.disconnect wires from top and bottom switches and chkf for continuity.they should be normaly open when the door is open and closed when door is closed.one of them will closed even when door is open.replace that bad one.

I strongly suggest that you do not attempt to adjust the hinges.

The door switch mounts are either cracked or need to be adjusted.

Door switch mount trouble is usually caused by slamming the door.

This may be a little more info that you need and it's from a Sharp service manual, but the general principles apply:

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

If the door sensing switch, secondary interlock switch and monitor switch do not operate properly due to a misadjustment, the following adjustment should be made.

4. Loosen the two (2) screws holding latch hook to the oven cavity front flange.

5. With door closed, adjust latch hook by moving it back and forth, and up and down. In and out play of the door allowed by the upper and lower position of the latch hook should be less than 0.5mm. The vertical position of the latch hook should be adjusted so that the door sensing switch
and secondary interlock switch are activated with the door closed. The horizontal position of the latch hook should be adjusted so that the plunger of the monitor switch is pressed with the door closed.

6. Secure the screws with washers firmly.

7. Check the operation of all switches. If each switch has not activated with the door closed, loosen screw and adjust the latch hook position.

After adjustment, check the following.

1. In and out play of door remains less than 0.5mm when in the latched position. First check upper position of latch hook, pushing and pulling upper portion of door toward the oven face. Then check lower portion of the latch Figure C-3. Latch Switch Adjustments hook, pushing and pulling upper portion of door toward the oven face. Both results (play in the door) should be less than 0.5mm.

2. The door sensing switch and secondary interlock switch interrupt the circuit before the door can be opened.

3. Monitor switch contacts close when door is opened.

4. Re-install outer case and check for microwave leakage around door with an approved microwave survey meter.

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As per a similar manual:

1. Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

2. Safety interlock switches: Primary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission in excess of 5 mW/cm2 at any point 5cm or more from
the external surface of the oven.

You need to be sure that if the meter comes with a styrofoam cone tip, that should be installed or it will give high readings.

Also, the meter should be calibrated periodically, typically annually.

If the meter gets dropped or bumped, that may throw it out of alignment.

The most common causes of excessive leakage are loose or misaligned door switch mounts or hinges and physical damage to the chassis of the oven.

The most common cause of the misalignment of door switch mounts is slamming the door.

I would be sure my meter is set up and calibrated, then I would be sure my door switch mounts are aligned & tightened properly.

From a similar manual:

1. Disconnect the power supply cord, and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor. If the door sensing switch, secondary interlock switch and monitor switch do not operate properly due to a misadjustment, the following adjustment should be made.

4. Loosen the two (2) screws holding latch hook to the oven cavity front flange.

5. With door closed, adjust latch hook by moving it back and forth, and up and down. In and out play of the door allowed by the upper and lower position of the latch hook should be less than 0.5mm. The vertical position of the latch hook should be adjusted so that the door sensing switch and secondary interlock switch are activated with the door closed. The horizontal position of the latch hook should be adjusted so that the plunger of the monitor switch is pressed with the door closed.

6. Secure the screws with washers firmly.

7. Check the operation of all switches. If each switch has not activated with the door closed, loosen screw and adjust the latch hook position.

After adjustment, check the following.

1. In and out play of door remains less than 0.5mm when in the
latched position. First check upper position of latch hook, pushing and pulling upper portion of door toward the oven face. Then check lower portion of the latch hook, pushing and pulling lower portion of the door toward the oven face. Both results (play in the door) should be less than 0.5mm.

2. The door sensing switch and secondary interlock switch interrupt the circuit before the door can be opened.

3. Monitor switch contacts close when door is opened.

4. Re-install outer case and check for microwave leakage around
door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)

Please write back with more details if you need further help.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.