Fish Hawk 840 Non-consistent readings

[DEFIANCE1]

My fishhawk in the last few weeks has not been working properly. The readings are all other the place. Even if i stop completely with no blow back it does not read consistent. No readings at all past 70feet. When i first got the unit i had this problem and adjusted the gain and got it working good. I have tried adjusting the gain, turning off all other electronics to make sure it was not getting interference, new batteries, checked all connections and use dielectric grease for all connections. Not really sure what else to try? Is there any way to figure out where the gain should be? such as turn all the way in or out and so many turns back? Any suggestions would be appreciated.

[rail bird]

Make sure you are using the best 9v batteries you can find, Duracell, or other top of the line akaline batteries. The batterries marked as heavy duty do not put out as much current as the alkaline types and did not seem to work for me.

Good Luck

[ray koziatek]

the gain is itty bitty adjustments ,pull out the circuit board and check for corrision ,if there is some use old toothbrush and gently clean make shure battery connections(wires) are soldered good also....also if you got a new fishfinder some will interfere with readngs ...i have to turn off finder to get constant accurete readings due to my mistake of mounting transducers too close....also look cable over good as it might of got pinched or messed up and also look at connections for corrision ....but check the battery first......

[GAMBLER]

Ditch the old style probe and buy the X4 probe. It will work with your old unit. I purchased mine this spring and it is way better than the old style probe. It runs on AA batteries and I just replaced the original set on Saturday (20 or so trips). IT deos not skip around at all. I ran my prober down 200' and it was still reading perfect.

[DEFIANCE1]

I am going to go over everything before i head out again then give it a try and really try to adjust the gain. If it does not work It looks like the X4 will be on my Christmas list. Thanks for the suggestions.

[ray koziatek]

dont know where your at ..i have a spare probe "not for sale" but you could give it a try to test everything else

[Feelin Reel]

I had the same problems, buy a depth raider, in my opinion it's a much better unit

[Organized Slime]

Gain Control

the gain control is a 20 turn pot with no end stops. Gain only effects the probe temp & speed readings. If the downrigger functions are only displyed as dashes more gain may be required. Adjust the pot in 1/2 turn increments and allow 30 seconds between adjustments for circuit stabilization. If the downrigger readings are very erratic sometimes being unbelievable then more or less gain may be required. Reduce gain in 1/4 turn increments. Adjustments usually do not require more than one full turn of the gain pot in either direction. If you feel you have lost touch with the original factory gain setting turn the gain control about 20 full turns counter clockwise & then 6 full turns clockwise to duplicate the factory setting.

Just dug out my manual, have the 840 with the new X4 probe and & having the exact same problems you mentioned. Hope this helps? I have the 840 manual scanned & would gladly email to anyone in need.

[nautime]

Organized Slime...I would really appreciate a copy of the manual. I bought my unit used a long time ago with no manual, and just this summer it has been giving me erratic readings. I have tried playing with the gain, but have not been able to reset the factory settings. I did not realize that there was no stops. I thought my unit was screwed. I have no idea now were the gain is set.

My email add is nauti_me at hotmail.

Thanks a bunch.

Regards...Jake