Is my Chamberlain sensor board toast?

Hi Folks,

First post here trying to help a friend who is having issues with his Chamberlain garage door opener. 

I'm pretty handy but have not done much work on these openers. I have done a bunch of research online but have yet to stumble across a post that sounds the same as his problem. 

Ok, here is the deal. 
The primary issue is that when trying to close the door with either the wall-mounted controls or the wireless, the unit flashes the 10 times normally associated with a sensor block - except that there is no sensor block?

The sensors are working correctly as they both light and waving my hand in front of the beam flashes the green light on the receiving sensor. No issues there. 
The garage door itself moves freely with no binding or problems. It can be raised or lowered without any resistance. 
Unit obviously has power and the remote is programmed and operating normally. 

What happens is that as soon as you press the door button, the door moves barely at all and it then flashes the lamp 10 times which as I have learned, normally means a blocked sensor. He had also purchased a new set of Ryobi sensors because he initially thought it was just a bad sensor issue but both the original and new sets produce the same results. 

I took a stab at simply doing a hardwire bypass of the sensors at the unit end and that produced an interesting result. If you press the remote button while wiggling the wires or maybe I was disconnecting a reconnecting a wire, the door would close however the condition would come straight back again once the door pulled to the open position. The door does stay down when closed and does stay up when opened, you just can't use the remote to close it. 

I then found some information on bad solder joints to the PCB and as a pretty good electronics guy, I pulled the sensor board and reflowed the solder on all of the connector pins mounted to the PCB. I thought for sure this was the fix but nope, same condition and for whatever reason now when I try to do the wire jiggle thing, it doesn't work to close the door anymore. 

So there is no intel I have found about this particular type of problem and I am starting to believe that the sensor board is just cooked. Does anyone have any deeper intel on this sort of problem? I have run the opener through all the basics:

- Made sure sensor alignment was dead on
- Reset the opening and closing limits
- Removed the chain to see if that was binding and since it was not, reset the chain tension
- Inspected all the rollers and hinges for problems - there aren't any
- Played with the open and close force adjustments - no problems
- Re-flowed the solder joints on the sensor PCB

This may simply be a classic case of having just a bad circuit board and if so, they are not expensive to replace. 
Just don't want to throw money at something until I am convinced. 

Thanks and great to be part of the forum

Seems like that's really your only other option. Especially after messing with anything in the circuit that'll be your best bet. 

The only other thing I can think of is if the sensor wires themselves are stapled too tight. I've had scenarios where the staple was so tight it would make contact between the two and cause the motor to do exactly that. You can also try wiring the sensors to the motor directly. ( Use a small wire to connect it so you know staples won't cause any issue. At least to rule out that final piece )

agarageguy wrote:Seems like that's really your only other option. Especially after messing with anything in the circuit that'll be your best bet. 

The only other thing I can think of is if the sensor wires themselves are stapled too tight. I've had scenarios where the staple was so tight it would make contact between the two and cause the motor to do exactly that. You can also try wiring the sensors to the motor directly. ( Use a small wire to connect it so you know staples won't cause any issue. At least to rule out that final piece )

Thank you sir.

We had two sets of sensors; the original ones which ran through the walls to the unit and then the new Ryobi sensors which we just laid across the floor. 
There was definitely nothing standing in the way of the new sensors so I am going to go with the fix. Found a backbox locally in Vegas for 40.00 so at that price, why guess any further. 
Appreciate very much the response. 

Bernie