Repair of Roomba Bump Sensor
星期四, 十二月 31st, 2009I bought my roomba from Frys in Los Angles and bring it all the way back to China at 2008-09-28. It's a "Made in China" product but it’s impossible to buy it in China, since the factory located in a tax free/export only district.
During one and half years of use, my Roomba 560 failed a few times however I finally make the dead roomba back to life again. Here is the experience I'd like to share with you.
To test your Roomba function with service manual
It's the best way to know what fails and test you roomba is put it into service mode. You could download and read the service manual here: 5xx Series Roomba Service Manual
For example, to test bumper, put roomba to service mode, move to function 3, and press each side of bumpers to see if it works.
Bumper Sensor Fails – Running in backward/spin and stop with 9 beeps
Roomba use IRED(infrared led) detect bump arm movement. There are two small arms behind bumper, when roomba run into something, bumper fall back push one arm. That's how the switch works.
And from this picture you can see that the bump sensor at this side is quite close to a cluster of power supply triode. When roomba is running the temperature of this area will be higher than normal. Well, under such high temperature environment IRED degrade in a much higher rate.
(2010-1-8: few days after I wrote this article, the other bump sensor in left malfunctioned... anyway I fixed it with new IRED and hopefully it could run for another year. )
I know some people tried to "fix" this issue by modify mother board, but I do not agree with that. In China we believe “Whoever started the trouble should end it.” . And yes I agree that new diode pair will also fails after one or two years, but it’s fare and long enough for roomba, in the end of day it’s just a cleaning toy but not appliance.