Shark IQ RV1001 IR Cliff Sensor Bypass or Repair

Thread Starter

SpiderSpartanju

Joined Apr 10, 2009
69
I'm not sure if this is the right place for this (or if there is a right place). I have a Shark RV1001 robot vacuum that the IR cliff sensors stopped working on one side. The probing I've done looks like there is a short somewhere. On the working side the IR-LEDs get 15V on the + side and 14V on the - side. On the dead side both leads are getting 15V. If I plug the sensors from the dead side into the working side they work. I have a couple questions.

1) Are there any likely components I could/should check for failure, ie: transistors, capacitors, or resistors?
2) Any general tips for reverse engineering/troubleshooting/repairing circuits like these?

Thanks for any help.
 

Dodgydave

Joined Jun 22, 2012
10,087
So it's not the sensor then, what happens if you put the good sensor into the bad side , sounds like you're missing a ground..
 

Thread Starter

SpiderSpartanju

Joined Apr 10, 2009
69
So it's not the sensor then, what happens if you put the good sensor into the bad side , sounds like you're missing a ground..
Missing ground is entirely possible. When I put the good sensor on the bad side, I get nothing. I did some probing and got the following Voltage results:
Working Side (Connected)Broken Side (Disconnected)Broken Side (Connected)
RED14.515.815.8
WHT13.6015
YLW3.23.273.28
BLK000
RED4.554.5
WHT4.554.5
YLW13.6015
BLK12.7014
ORG3.23.283.28
GRN000

The bold go to the side sensor and the italics go to the cliff sensor. It's strange to me that I'm seeing close to the appropriate voltage drop at the IR LEDs that are not on. I think I may try to pull the signal from the working side and cluge it onto the broken side to see the brains receive the signal. Then I could at least use the bot in a spot where there are no stairs.
 

Thread Starter

SpiderSpartanju

Joined Apr 10, 2009
69
I think I may have just figured this out. I noticed when I unplugged the side/bottom combo connector on the working side, the other lone cliff sensor went out. I moved the lone sensor from the working side over to the broken side and now the combo connector works. I'm not sure if that sensor is shorted or open, but if I can get a replacement for this one I think I'll be back working.
 

MrSalts

Joined Apr 2, 2020
714
Issues like,this are typically bad crimps, loose pins on a connector or a poorly soldered joint. Over time, vibration from motors or bumps during operation or shipping cause the barely connected segment to no longer be connected. Measure continuity from solder pads on bottom of the LED edge detect board (with black and clear LED on it) to the connector on that board. Then connect the cable and measure from the solder pads to the connector on the next board. Make sure all four solder pads on + and - of each LED (actually an LED emitter and a phototransistor). Use ohms setting on your meter snd all measurements from solder pad on sensor board to corresponding pads on main board. All values should be about 10 ohms or less. Measure both the working and non-working assemblies.
 

Thread Starter

SpiderSpartanju

Joined Apr 10, 2009
69
I think I really got it now. Opened up the dead sensor and found some traces either burned or corroded away. I opened up one of the working sensors to verify/compare what should be there and soldered a few cluges in place. Plugged everything back in and I have that beautiful purple light! Now I just have to put it all back together and see if it works and hold up. 20210713_205945.jpg20210713_220637.jpg20210713_221029.jpg
 
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