navman 8120 card reader problems

Miller · 02 February 2013, 19:19

Any electronics experts on here?

2 questions:

1. My navman 8120 uses cmap card but when I stick a card in the reader it just says no card present....my friend has taken it apart and changed the ribbon and cleaned off a bit of corrosion on the connectors but it still isn't registering...any ideas?

2. What's the best way to fit an in hull transducer...does the transducer have to actually be in contact with the hull? Presently the frame is glued to the hull and the actual transducer screws into that..I don't think that comes in contact with the hull though

Thanks for any help

jyasaki · 04 February 2013, 00:51

For #2, there has to be some medium between the transducer face and the hull. Some use a pot (well some sort of open bottomed cup) filled with oil (mineral oil seems to be the oil of choice); I've heard some using silicone or polyurethane adhesives, or even epoxy. Your site does have to be single walled construction though. An inner layer with a foam core before the external hull material isn't going to transmit the signal through.

I haven't had much luck restoring card sockets. I effected a marginal repair on my old Lowrance unit by adding a layer of electrical tape to the SD card opposite the contacts; raised it up enough to get contact. Eventually died though.

jky

Miller · 05 February 2013, 13:27

Thanks for that... Can I use a gel of some sort that won't slop around so much?

peterthelight · 05 February 2013, 14:39

Using silicone (marine grade) is the best, I think. Use it to fill the void between the transducer and the hull. Make sure there are no air gaps. Any problems in the future and it is easy to cut out. Mine works perfectly fitted this way. Obviously the siting of it is important, close to the transom and as low as possible and facing the right way.