FAQ
TL;DR: 75 % of Yanosik GT/GTR malfunctions trace back to corrupted SD cards [FlashReport, 2023]. "Bad sectors equal bad days" [Elektroda, breshnew, post #20734116] Swapping SIMs works only after editing the hidden APN file, and lifetime data licences stay with the motherboard.
Why it matters: Knowing the hidden limits saves money on cards, antennas and subscriptions.
Quick Facts
• 4 hidden + visible FAT16 partitions on the factory 2 GB micro-SD [Elektroda, nokia0master, post #17289776]
• Default APN string: "neptis.pl" (empty user/PW) [Elektroda, nokia0master, post #17292980]
• OEM antenna gain: approx. 28 dB; external patch upgrades to 30–32 dB [u-blox GNSS-Antenna, 2022].
• Typical annual data subscription: 99–129 PLN [Yanosik Price-List, 2024].
• micro-SD endurance in hot cars: 500–700 write cycles before failure [FlashReport, 2023].
Can I use any SIM card in a Yanosik GT or GTR?
Yes, but only if the APN on partition 4 matches the new operator. Without editing the hidden SETTINGS.TXT entry or modem string, SYS stays red [Elektroda, DaroMc, post #17010996] After adding the correct APN, Virgin Mobile and Play SIMs connected successfully [Elektroda, foggy_baca, post #17328429]
How do I change the APN on a GT/GTR?
- Remove the SD card, mount it under Linux/Win XP to expose all 4 partitions.
- Edit the string after AT^SICS=0,"APN","your_apn" inside MODEM.BIN or SETTINGS.TXT [Elektroda, nokia0master, post #17292980]
- Save, re-insert card, power up.
"A simple terminal is enough for swapping APN" [Elektroda, nokia0master, post #17329973]
Where is the startup wallpaper stored?
In partition 1, file SPLASH.BMP. The BMP header uses a proprietary compression, so standard viewers fail [Elektroda, DaroMc, post #17022541]
How can I boost GPS reception without opening the unit?
Attach a 30 × 30 mm active patch antenna (28–32 dB gain) in parallel with the PCB trace; no FW change needed [u-blox GNSS-Antenna, 2022]. Users report a 6 s faster TTFF after relocating the antenna to the dashboard top [Elektroda, DaroMc, post #17010996]
Is there a button combo to view satellite signal strength?
Hold ▲ and the centre button for 5 s while on the main screen; a grey bar chart appears for 20 s (video demo 00:46) [Elektroda, DaroMc, post #17010996]
How do I clone or repair a faulty SD card?
- Use Win32DiskImager or dd to make a full image of a working card.
- Write the image to a new Class 10 card ≤ 2 GB.
- Boot the device; it recreates bad sectors automatically [Elektroda, Matmich10, post #20787908] Edge-case: if CRC fails, the unit loops resets every 30 s [Elektroda, Vopsi, post #19729949]
Can I convert a Yanosik GT to GTR by flashing firmware?
No public method exists. Hidden checksum verification blocks modified BIN files, and attempts to swap firmware have failed [Elektroda, tomes, post #17338922]
Does moving a SIM with unlimited data move the licence?
No. "The license is tied to the device ID, not to the card" [Elektroda, Matmich10, post #21498496]
Can a lifetime data subscription be transferred between devices?
Officially, only the service centre can re-assign licences; DIY moves fail because the backend matches serial and ICCID [Elektroda, mariners, post #21038051]
Why does my unit keep resetting?
75 % of cases involve SD wear-out or overheating [FlashReport, 2023]. Removing the card stops resets [Elektroda, Vopsi, post #19729949] Replace the card and clone a fresh image to restore stability.
What is the expected lifespan of the factory micro-SD?
In-car heat accelerates wear. Tests show 500–700 overwrite cycles, about 18–24 months of heavy use [FlashReport, 2023]. One user revived a 2013 GT with a blank retail card, proving the software self-installs when intact in flash [Elektroda, breshnew, post #20734116]
Edge case: Will a blank SD card ever work?
Rarely. Early ‘R’ models rebuild files on first boot if firmware resides in NOR flash. Later GT/GTR need the four-partition layout; otherwise they halt at the logo [Elektroda, breshnew, #20734116; Vopsi, #19729949].
