# Garmin 178C Sonar Problems



## SCUBA Junkie (Oct 2, 2007)

I have a Garmin 178C GPS/Sonar combo, about 2 years old. Last time out, I noticed the sonar having intermitent problems. I assumed a problem with the transducer, and ordered a replacement. Hooked everything up, added power, and noticed for the first few moments, the ducer pinged at very steady rate. It was not in the water, so no sonar detail, just hearing and feeling the pulses. After a short time, the pulses started becoming erratic, stopping for a few beats, skipping beats, and then steady for a short time. I am now thinking it may be a problem with the pulse generating circuit in the main unit, but I've never known a solid state electronic to become erratic; most just go out al together. The unit is out of warranty, so I'm looking for advise.


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## SonShine Fishing (Oct 5, 2007)

I had problems with my 178C a few years ago. Downloaded a software update from Garmin and solved all my problems. The download was free from their website but you will need the cable to connect to your PC. The 17 pin cable fits several different Garmin models. I am in the Ft Walton Bch area and have the cable.


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## SCUBA Junkie (Oct 2, 2007)

I have the cables, so I'll give it a try, thanks.


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## jsaddiction (Oct 2, 2007)

Sounds like you are experiencing normal ops. Most Depth sounders will start looking for bottom. Once it has realized that the bottom is either too deep or there isn't one (like when there is no water) it will start to change its pulse rates to both not wear out the transducer and to look for a really deep bottom. I would say put it in the water and watch it. If that doesn't work then up date the firmware like stated above and try again. Then it if it still doesn't work then I would say that the unit it self needs replacing.

Justin


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