Hello All,
Well, with the help of the excellent web site, I determined that my Roomba 560’s right bumper sensor had a fault. So i ordered new emitter and photo-transistors, swapped them out but it still has the fault. If anyone has any other ideas, I would VERY much appreciate any help or direction. The thing is just over a year old and my wife really loves it. Cheers, Scott
Thank you Vayvazyan for your considered and detailed response. I really appreciate it. Will give your suggestions a try and report back.
Ok, I rechecked my soldering. One spot didn’t look too good. Redid it and now our Roomba is back in business!! That’s SO much. I get to be the hero thanks to your help.
I, too, am now running into this issue. However, I bought the replacement board and I’m fairly confident that I did a good job soldering the wires into place. What’s the best way to test for a failed wire?
Also, what’s the best way to test the sensor with the battery removed? I was pretty heartbroken when I put everything back together and it was still failing 
Thanks so much for the reply! A little more information:
When I do the bumper test in diagnostics mode, the “Dock” button is always lit up. This was the case before and after replacing the left bumper sensor.
When I look at the sensors using a digital camera, the left cliff sensor is not visible. Are these two things related, or do I also have a busted cliff sensor?
You could test the continuity of the wires. Although, we rarely see problems with the wires themselves. You may want to double check that the wires are going to the right connections.
Make sure that the two IR diodes line up properly and that you see no cold solder joints on the board itself. There may also be misalignment of the diodes which can cause the diode to sit crooked and have a weak signal.
The best way to test the sensors would be to use the viewfinder of a digital camera to see if the emitter is bright. But, for this you will need to have the battery installed. If one of the sensors is working, you will be able to compare the brightness compared to the other.
In the event that the board is defective, you may contact us via our support center and we will gladly replace your sensor board.
From what you are explaining, it seems that you have a defective bumper sensor and a defective cliff sensor. Although, the defective cliff sensor is not related to your bumper issue.
In this case, you may want to consider the purchase of a complete cliff sensor and bumper sensor harness. Considering that the bumper sensor did not fix your issue, we could go ahead and exchange the bumper sensor for the complete harness. Please contact us via our support center and we will gladly send you information for this exchange.
Hi Worldlyone,
Welcome to the RobotShop forum.
First make sure that the two components you ordered are placed correctly (the photo-transistor should be near the wiring connections, while the emitter should be on the far side of the bumper sensor board) and are at the same height. Also make sure the two lenses are facing each other.
From our experience the photo-transistor does not fail, so you can start by having the bumper sensors disassembled and testing the emitter’s output using a digital camera; most cameras pick up on the IR from the emitter. If we can establish that the parts you’ve purchased are not defective, then doublecheck your solder joints to make sure you don’t have any cold joints. Sometimes even the solder pad (or ring in this case) can come loose when desoldering the old emitter. If this has happened, you’ll likely need to scratch away at the board surface to reveal the trace that connects to the solder ring, and solder the emitter to that trace instead. It won’t be as neat or pretty, but it should work.
When you put the bumper sensor housing back together, test out the lever by pressing it down and up. If it moves oddly or is difficult to press, then the housing may not have been put together properly. If you need any tips on how to put it back together, please see the repair manual located here (it specifically deals with replacing the IR sensor boards, but the images and information are still useful).
If it’s not a defective emitter and the soldering and reassembly of the bumper sensor board housing is correct, then it may be a problem with either the board or perhaps even the harness. You may want to check the four wires going from each sensor board to the motherboard for any damage.
Please let us know what you find out and if you have any questions. We’ll be glad to help you further.
Thanks,
