Just finished installing used helix 7. Display gets really hot when I power it up, over 125 degrees in a minute or so on an infrared thermo. Wired directly to starting batt with about a 20' run of Ancor 12/2. Shows 90 degrees when wired into 12v power supply inside garage.

With or without the transducer connected?
Normal or Simulator?

Wayne, was with or without transducer and both normal and simulator. It's not as hot now, staying at a reasonable temp. But now it shuts down when I go to a chart view. Does that in simulator and normal. It will either say loading charts for a long time or shut down

May need a trip to Humminbird to fix it.

Try this:
Export the waypoint library to a memory card, remove it, and do a Format Nav Directories to clear the memory and check for high temp. High temp may be caused by excessive processing due to corrupt waypoints.
Also make sure the unit is getting full voltage, chart/GPS issues is a sign of low voltage.

I have a Helix 7 SI G2 on my desk and the screen gets about 10 degrees warmer than the cabinet after about 10 minutes in Simulator---81 vs 71 degrees IR measured. The temp will decrease if the backlighting is reduced to 7.

Thanks Wayne, I'll try that. This is a 7 SI G2N. I haven't used on the water yet and only saved a few waypoints. Does it matter that I created waypoints in simulator? Voltage running 12.85 in boat and 13.2 on power supply.

I did software update and loaded HB basemap prior to install. I don't have another mp card yet. Seems to get hottest and really struggle running basemap, much better with unimap. Is that typical?

Simulator is OK to add GPS data or do software updates.
I have some Tracks that were created with Google Earth Path, translated to Humminbird Tracks and loaded to my units on my desk in Simulator.

Compared to the Helix 9, 10, and 12, the HB basemap file for the Helix 5 and 7 is small.

Processing more data will add extra heat, but it shouldn't be excessive.

Problems are related to basemap. Works normally with unimap. When switched to auto or basemap, it shuts down or gets extremely hot. HB says no way to remove/uninstall basemap. Only option is to return for service at nearly $250

Unit worked fine prior to install of latest software and upgrade to basemap. Some "upgrade"

Can you reinstall the older version of software to see if the heat problem goes away? If you can't do that, you might try installing the update again. I'm wondering if it corrupted something during installation that is now causing the heat issue.

Thanks for all the suggestions. Bad news is there's no way to revert to old settings, unit has to go back to HB. Good news is they will cover under warranty (it's not - 2nd owner) since it has less than 50 hours.