Have them turn it in and keep the power button pressed down for at least 10 seconds after it powers up.
Many of us have done that if ours started acting wonky or schizophrenic and this sometimes brought them back into line.
Fisher swears there is no reset on this thing but most if us that did this disagreed because it did help.
This was on units that were jumpy, this one seems to have much deeper problems than that.
I saw one act like this in a video on YouTube.
The owner was using it in a shallow lake a few weeks before and it slipped out of his hands and took a bath.
He said it died but after he let it dry out for several days it powered back up and he just assumed it was working ok again.
Then he used it in another video where he compared it against an Ace 250...it did not perform very well at all.
No depth, jumpy crazy numbers, the idiot did not seem to understand this thing was wrecked and even after I told him to get it into service because he was doing a disservice to anyone that watched that vid because they will get the idea that this was how the F2 was supposed to work.
The idiot still kept that video up for years after that.
This is either a coil problem or a board problem.
If they could change over to another coil that should narrow it down to which one is the problem, most of these were sold in either a 2 or 3 coil package so if there is another one hanging around that is the first thing they need to do.
These had 5 year warranties if bought new to the original owner, sending it in should cost them just shipping one way and they still repair them.
Unless they see signs of abuse like water damage...then it will cost many bucks to repair and they might choose not to repair it at all.
Good luck.
