Bosch washer WFMC6400UC won't start
Posted 25 September 2011 - 12:28 PM
I would like a link to a repair manual.
Posted 07 November 2011 - 10:37 AM
In my case, the start light would flash but there was no solenoid click when start was pushed, same as his. I had the repair manual before doing any work, so I checked the resistance on the connector from the control module, without disassembling the door lock/switch as he did. I still wondered if there could be a door lock problem, since the resistance I got (he got the same value) was 121 ohms for both resistors versus the value shown in the repair manual of 159-211 ohms, but I figured unless the resistor was open or much farther off, it should probably work. It's a lot of work to get to the door lock, but that part is way cheaper than a control module, so I was tempted to replace it anyway, sure glad I didn't.
The first thing that put me off when I read the service manual is that the troubleshooting solution to 'washer won't start' is pretty vague. Says only to check for 120V or to check voltages to water valves and drum motor, if no voltage, replace the control module which was $292. For a 5 year old machine that cost me around $1600 and is supposed to be top of the line, it sure doesn't hold up like a Maytag! If it hadn't been for Yuri's post, I wouldn't have had a clue.
I had the same suspicion Yuri had that the start/stop button was the problem, since I couldn't even run self tests without it working. The troubleshooting sure didn't help with that.
For me, taking the control module board out of it's plastic housing was for me pretty hard. I'm not mechanically inclined and the service manual leaves out some details of how to take the board out of it's plastic case. There are some plastic fittings on the side of the board with their own plastic clips that need to be removed to get to the control module pc board, and there is a ribbon cable connecting the display to the board which has to be disconnected, which is not mentioned. I found the cable wouldn't extend far enough to get my fingers on it until I noticed some slack in it that I could remove, once I did that I carefully pulled the end of it that attached to the board.
Otherwise, I did everything the same as Yuri did, so his advice was dead on perfect! I had to buy some magnifying headgear so I could see better and a new soldering iron with a very small tip to desolder the metal cover plate around the start switch button on the control module pc board. Luckily, I had a pair of very fine pointed tweezers I saved from my days doing electronics manufacturing to grab the edges of the cover plate with one hand while I used the other for the soldering iron. Under the cover is the round bronze (I guess) upside down saucer plate (his words, entirely accurate) I cleaned it with alcohol and rotated it 90 degrees, same as he did, resoldered the cover, reassembled everything and the machine is now good for another 5 years, I hope. I haven't run diagnostics yet or any wash cycles, but have pressed start twice and got an immediate cycle start, versus before the fix when 40 pushes didn't work.
I sure would like to find someone at Bosch to complain to about this problem. At the very least they should offer a recall/repair for it. I intend to call their customer service about this, now that I know.
Thanks to Yuri, the Grand Master and this forum, which really rocks!
Posted 08 November 2011 - 10:52 PM
I fixed my Bosch washer using the same fix that Yuri, his handle is iapanovitch, posted on 22 December 2009 about a WFMC3200 that wouldn't start.
Link to that topic: http://appliantology...__1#entry137576
Need parts? Call our Parts Department now! 877-803-7957
Posted 01 August 2012 - 11:54 AM
This time I just took out the main board, didn't check anything else. I probed for continuity across the switch by touching plated-thru holes on the board with my meter tips, and could see that it wasn't closing when depressed, whereas other buttons were okay.
I took apart the 'Reduced Ironing' button and swapped the metal cover plate, green plastic button and round bronze disc with the Start button. The 'Reduced Ironing' bronze disc seemed like it had both more curvature, and more uniform curvature, than my old start button disc had. This is only qualitative, based on light reflection, I could be wrong. It seemed to have a ridge in it, like a hard taco shell has, but only slight, not nearly that much. I put it in, cup side down like it should be, with the ridge perpendicular to the imaginary line connecting the outside contacts and the center contact. You have to see this to understand, my camera couldn't do it justice so I didn't take a picture.
Since we never use Reduced Ironing, I should now have a new switch.
Worked 5 times at first push. The reliability clock has re-started and is ticking away...we will see.
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users