RPM’s, Depth flaking

[Lisette]

Recently the depth reading has started flaking out - not reading, reporting 500+ feet of depth, etc. Yesterday, the RPM’s and temp readings stopped reporting.
Any suggestions on how to troubleshoot?
Also, any idea what version, model transducer this unit has? See photo

The product manuals in hand are the TZTL15F, Radar Sensor DRS2D, Autopilot 700 with Integrated Heading Sensor PG-700. The software version is 1950151-08.01

 

[Quitsa]

Recently the depth reading has started flaking out - not reading, reporting 500+ feet of depth, etc. Yesterday, the RPM’s and temp readings stopped reporting.
Any suggestions on how to troubleshoot?
Also, any idea what version, model transducer this unit has? See photo

That looks like an old Airmar DST 800 series. If you unscrew the upper portion, it will be possible to remove the entire transducer assembly. They come with a blanking plug to put in the hole so it can be done with the boat in the water. Then you can check the paddlewheel (I assume you didn't mean rpms but rather speed through the water) and the sounder window for fouling and clean it up. It is possible to buy a replacement paddlewheel if the existing one is missing a vane or otherwise broken.

It may have just reached the end of its life. That looks like an early version. The photo below is what the removable part looks like: