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APPLIANCE DEAN

BOSCH REFRIGERATOR B20CS50SNS-01 FROSTING/DEFROSTING

5 posts in this topic

This unit like most of the B20CS units had one of only two issues I typically run into which is the evap fan was dead. So I replaced the evap fan motor. I checked the heater ran a forced defrost because ofcourse if the fan is not working it will turn the coils into a block of frost. The heater worked fine the sensors checked good. A week later my evap fan motor is out, the condeser fan motor and the fresh food fan motor. Not only is that weird but I noticed the unit had the heater on and the compressor on at the same time. I have never seen a refrigerator have both the compressor and the heater on at the same time. After checking out put voltage on the control unit it was very clear non of the fans were being supplied with power. but what striked me as weird is why the unit was cooling and defrosting at the same time. I'm left with one conclusion BAD CONTROL BOARD. Has anyone run into this before? I also reset this thing when I initially ran the defrost cycle so its not like I left it in diagnostic mode.

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Need appliance parts? Call 877-803-7957 now!

I haven't seen this issue with the Bosch, but it wouldn't surprise me.  Sound like new Main PCB time, provided the outlet voltage is correct and polarized.  Were there any fault codes shown during diagnostics, like "C1" or "F3"?

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very common with jazz brd -compressor relay will be stuck closed - causing it to keep compressor/condenser fan always on even during defrost cycles.

Relay for compressor must be stuck / No power to fans at this time due to unit in defrost.

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Pull a relay off a scrap Lg or samsung control brd. I always save brds for parts. im able to save customer some $ .

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Main PCB  Part number: 00640603

Part number: 00640603

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