Why these guides exist
Marine electronics support forums are full of "bump", "same problem here", and links to JustAnswer paywalls. Manufacturer support pages tell you to call your dealer. These guides cut through both: each one is a step-by-step diagnostic sequence for a specific device and symptom, built around the actual failure modes that technicians see, not generic advice.
Device-specific
Each guide targets a specific model or series — not "chartplotters in general." Lowrance Hook Reveal vs HDS have different failure modes.
Diagnosis sequence
Start with the cheapest, most-common fix and work toward the expensive ones. Every guide starts with what to rule out before spending money.
Parts links
When replacement parts are needed, we link to what actually works — not just "contact your dealer."
Guides by brand
Lowrance
- Lowrance Hook Reveal Black Screen at Startup
Corrupted chart card, voltage drop, and firmware hang — in that order. Most resolve with chart card removal + power cycle. - Lowrance No GPS Fix: Satellite Search Won't Resolve
Internal antenna obstruction, cold-start delay, and GPS source misconfiguration. External antenna required for under-hardtop installs. - Lowrance HDS Sonar Not Reading Depth
Transducer connector seating, transducer type mismatch in software, and frequency setting issues — before assuming transducer failure.
Raymarine
- Raymarine Axiom Won't Power On
Drain wire grounding, supply voltage, and fuse are the three causes. The drain wire is the most-missed install requirement. - Raymarine Axiom Touchscreen Not Responding
Saltwater film on the capacitive screen causes total input lockout. Firmware hang is second. Rinse, dry, and hard-reset. - Raymarine Axiom Software Update Stuck or Failed
Slow SD card causes 'Extracting' to stall indefinitely. Use Class 10, fresh download, FAT32 format. - Raymarine Chartplotter No GPS Fix
Antenna source selection, dead coin cell (GPS almanac clock), and external antenna for hardtop installs.
Simrad
- Simrad NSS Touchscreen Frozen
Hard reset, corrupted chart card, and early evo2 flex cable issues. Check firmware version. - Simrad GPS No Fix: Position Won't Resolve
GPS source set to offline network device, GLONASS disabled, or antenna cable routing interference. - Simrad Autopilot Not Holding Course
Read the alarm code first — compass calibration, rudder feedback sensor, or drive unit. Diagnosis branches from the code.
Garmin
- Garmin ECHOMAP Transducer Not Detected
8-pin connector pin corrosion is the primary cause. Clean connector before assuming transducer failure. - Garmin Chartplotter Frozen at Startup Screen
Remove microSD chart card first — corrupted card causes most startup freezes. Force power-off requires 20-second hold.
All Marine Electronics Guides
- Lowrance Hook Reveal Black Screen at Startup
- Lowrance No GPS Fix: Satellite Search Won't Resolve
- Lowrance HDS Sonar Not Reading Depth
- Raymarine Axiom Won't Power On
- Raymarine Axiom Touchscreen Not Responding
- Raymarine Axiom Software Update Stuck or Failed
- Raymarine Chartplotter No GPS Fix
- Simrad NSS Touchscreen Frozen
- Simrad GPS No Fix: Position Won't Resolve
- Simrad Autopilot Not Holding Course
- Garmin ECHOMAP Transducer Not Detected
- Garmin Chartplotter Frozen at Startup Screen