Will not start, shows no sign of power

Dishwasher Repair
1

The other night I went to start the dishwasher and there was no response. It worked fine the night before, and there was no unusual electrical activity in the house that day. I checked with a meter and there is power to the on switch. I purchased a new switch and changed it, but that didn’t change anything.

Does anyone have a suggestion on what I might try next?

Thanks,

2

Remove the control module and inspect it for a burned spots. As far as I know you already fixed a broken solder joint once before (http://forum.appliancepartspros.com/dishwasher-repair/17989-bosch-dishwasher-heater-assembly-replacement.html). It is probably time for a new control module.

Here are the break down diagrams and Replacement parts for BOSCH SHU6805 UC/06 (FD 7705-7912) | AppliancePartsPros.com

Gene.

3

Just replaced the control module, unfortunately there is no change. Still no signs of life, although power is still there at the switch. Any other ideas?

Thanks, Tim

4

Tim,

Did you check the switch on the door latch?

Also check the incoming power to the control module according to the wiring diagrams and instructions in the troubleshooting manual from one of our previous posts: http://forum.appliancepartspros.com/dishwasher-repair/7123-bosch-dishwasher-troubleshoot-manual.html

Gene.

5

Gene:

When the door is closed (engaging the power switch) and the power switch is placed in the “on” position, I register power at the incoming connection to the control panel. Still no activity though.

Is there another fuse somewhere else in the assembly? I see nothing in the front door area that is burned out.

Not sure what else to check, but somewhere a connection is not being made, and since the control panel is now brand new, it doesn’t seem like it could be that.

Thanks, Tim

6

Are you able to run the self test?

Gene.

7

Unfortunately no, I get no signs of power at all. There is no response, lights or any actitivy when I engage the on switch. I have been able to verify that when the on switch is engaged, there is power coming to the control panel, but none of the lights anywhere on the unit come on, even for a moment.

Thanks, Tim

8

[QUOTE=tmueller1212;72399]…I have been able to verify that when the on switch is engaged, there is power coming to the control panel…[/QUOTE]

Tim,

Can you be more specific on how did you do it?

Gene.

9

I used a meter, one lead to a ground, the other lead to the end of the grey/black and black wire connection that attaches to the control panel. When the door is closed and the switch is on, there is power. When the switch is off, there is no power.

10

According to the wiring diagram you have to measure the voltage between the Black wire (I2.1-2) and the White/Red wire (I2.1-1). Possible the white (neutral) wire is broken or there is no continuity between the terminals 1 & 2 on the “on-off”.

Gene.

11

I am out of town now and won’t be able to check this until Thursday evening, but just to make sure I understand, I would do the following:

close door and turn on off switch to “on” position
disconnect both the black wire and white/red wire connections from the control panel
check voltage between the black wire and the white/red wire

Thanks for your help.
Tim

12

I think i was able to do the correct test. I set my meter such that it was registering 120 at an outlet. There are five connections to the on-off switch and my results were as follows.

Red/White - 40 to black
White - 75 to black
black
Single white - 40 to black
Double white - 40 to black

I am not sure how to interpret those results. Do they tell you anything?

Thanks, Tim

13

[QUOTE=tmueller1212;73874]I think i was able to do the correct test. I set my meter such that it was registering 120 at an outlet. There are five connections to the on-off switch and my results were as follows.

Red/White - 40 to black
White - 75 to black
black
Single white - 40 to black
Double white - 40 to black

I am not sure how to interpret those results. Do they tell you anything?

Thanks, Tim[/QUOTE]
There is no proper power to the control module. Remove the wires from the “on-off” switch.

Check the voltage between the incoming white and black wires.

Check for continuity between the terminals 1 & 2, 3 & 4 and 5 & 6 on the switch while the switch in “on” position.Post the results.

Gene.

14

Removed the wires from the “on-off” switch.

Voltage between the incoming white and black wires = 75V

Check for continuity between the terminals on the switch, with the wires disconnected and while the switch is in the “on” position:

1 & 2 = full continuity
3 & 4 = full continuity
5 & 6 = no continuity

I got the same results on the new switch on the machine which I purchased initially in trying to fix this problem, and the old switch.

Thanks, Tim

15

[QUOTE=tmueller1212;74033]…Voltage between the incoming white and black wires = [COLOR=“Red”]75V[/COLOR]…[/QUOTE]

Tim,

The problem is outside the dishwasher or at the power cord connection to the dishwasher.

Gene.

16

Gene:
You are correct, and I am not too bright. Should have checked that connection in the very beginning, but was thrown off because there was power to the switch still. The connection between the dishwasher and power had some sort of short in it and had gradually melted the wires, somehow without throwing the breaker or immediately shutting down the dishwasher. As soon as I removed the bottom panel it was obvious.

Thanks so much for all your help. Sorry I was such a dimwit.

Tim

17

You are welcome. I’m glad you were able to fix it.

Gene.

18

I had power to the switch on the hot lead but the neutral wire was broken inside the harness at the bottom of the door probably from opening and closing the door. Check that. It happens on many Bosch