4210 not recognizing remote or vw

[mh01]

My 4210 wasn't seeing the remote or VW. I ran the diagnostics and it failed theRcon test. I replaced the front bumper with a used one and I'm getting the same results. I verified that the remote and vw are emitting IR. I find it hard to believe both sensors are bad.

Does anyone know what might cause this issue?

[mfortuna]

Check the other end of the cable were it attaches to the controller board. It could be a bad controller board.

[mh01]

I checked the connections. It still doesn't work. I don't care about the remote, but the VW's and home locating would be nice.

I don't really want to replace the system board but it might be my only option. I wish there was a way to check the remote/VW sensor.....

[mfortuna]

I am not sure if Gordon's schematic set includes the IR sensor. Try searching for schematic and you may find it. One other possibility is the cable may have gone bad from flexing.

[Gordon]

... I wish there was a way to check the remote/VW sensor.....

Visit this post to obtain the IRM's datasheet: viewtopic.php?p=68843#p68843

After you study the IRM's datasheet you should be able to envision a bench setup to roughly check the IRM. An O-scope is really required but you might get an indication of activity via a DVM when the IRM is stimulated with a VWU (not the Remote). I think the DVM will read about half the Vcc level while the VWU's signal is being processed, and nothing otherwise.

I would guess your greatest hassle will be to figure out how to connect test leads to an IRM wired for Roomba use!

Very few (like 'one or two') of these IRMs have required replacement over years 2002 to present.

No schematic of this sensor's application circuit has been posted, but that circuit has been on my list of things to do for years. I spent time today tracing it out and can attest to the fact there are no active components between J23 (where the cable from the Bumper shell interfaces with the main_PCA) and the system's micro controller unit. No components in this circuit are stressed via heating or voltage, so there is little incentive for parts to fail.

The component that could be most disruptive, if suffering a huge value shift, is R197 (aft face of PCB, far left end of board at upper corner). You might verify its resistance is nominally 10k ohms.

Are you really convinced that the interface cable's three RED, BLU, BLK wired plug-sockets (of seven sockets connecting to "J1" on the Bumper's PCA) have continuity to the three sockets in J23's mobo plug?