diff --git a/firmware/src/logic/cfg_mem.cpp b/firmware/src/logic/cfg_mem.cpp
index 0ac10e5..eea5229 100644
--- a/firmware/src/logic/cfg_mem.cpp
+++ b/firmware/src/logic/cfg_mem.cpp
@@ -16,6 +16,7 @@ static const uint16_t addr_max_hbrake_time = 0x0006;
 static const uint16_t addr_lock_current    = 0x0008;
 static const uint16_t addr_max_out_voltage = 0x000A;
 static const uint16_t addr_min_out_voltage = 0x000C;
+static const uint16_t addr_cfg_good        = 0x000D;
 
 static const uint8_t def_btn_force = 0;
 static const uint8_t def_pot_mode = 0;
@@ -28,15 +29,13 @@ static const uint16_t def_lock_current = 4500;
 static const uint16_t def_max_out_voltage = 7000;
 static const uint16_t def_min_out_voltage = 200;
 
-static const uint16_t lim_saved_lock_current = 6000;
-static const uint16_t lim_saved_max_voltage = 8000;
-static const uint16_t lim_saved_min_voltage = 1000;
-
 /**** Private variables ****/
 /**** Private function declarations ****/
 /**** Public function definitions ****/
 logic::CfgMemory::CfgMemory(void)
 {	
+	this->cfg_good    = 0;
+	
 	this->mem_btn_force    = 0;
 	this->mem_bmode        = 0;
 	this->mem_pot_mode     = 0;
@@ -58,6 +57,7 @@ logic::CfgMemory::~CfgMemory(void)
 
 void logic::CfgMemory::init(void)
 {
+	uint8_t cfg_good_magic    = mcu::eeprom_read8b(addr_cfg_good);
 	this->mem_btn_force       = mcu::eeprom_read8b(addr_btn_force);
 	this->mem_bmode           = mcu::eeprom_read8b(addr_bmode);
 	this->mem_pot_mode        = mcu::eeprom_read8b(addr_pot_mode);
@@ -70,68 +70,22 @@ void logic::CfgMemory::init(void)
 	this->mem_min_out_voltage = mcu::eeprom_read16b(addr_min_out_voltage);
 	
 	// Validate EEPROM data
-	if(this->mem_btn_force > 100)
+	if(cfg_good_magic == 0x37) this->cfg_good = 1;
+	else this->cfg_good = 0;
+	
+	if(this->cfg_good != 1)
 	{
 		this->mem_btn_force = def_btn_force;
-		mcu::eeprom_write8b(addr_btn_force, this->mem_btn_force);
-	};
-	
-	if(this->mem_bmode > 2)
-	{
 		this->mem_bmode = def_bmode;
-		mcu::eeprom_write8b(addr_bmode, this->mem_bmode);
-	};
-	
-	if(this->mem_pot_mode > 1)
-	{
 		this->mem_pot_mode = def_pot_mode;
-		mcu::eeprom_write8b(addr_pot_mode, this->mem_pot_mode);
-	};
-	
-	if(this->mem_dsp_brigth > 100)
-	{
 		this->mem_dsp_brigth = def_brigth;
-		mcu::eeprom_write8b(addr_dsp_brigth, this->mem_dsp_brigth);
-	};
-	
-	if(this->mem_dsp_dimm > 100)
-	{
 		this->mem_dsp_dimm = def_dimm;
-		mcu::eeprom_write8b(addr_dsp_dimm, this->mem_dsp_dimm);
-	};
-	
-	if(this->mem_brake_force > 100)
-	{
 		this->mem_brake_force = def_brake_force;
-		mcu::eeprom_write8b(addr_brake_force, this->mem_brake_force);
-	};
-	
-	/*
-	No wrong value
-	if(this->mem_max_hbrake_time > 1000)
-	{
 		this->mem_max_hbrake_time = def_max_hbrake_time;
-		mcu::eeprom_write16b(addr_lock_current, this->mem_max_hbrake_time);
-	};
-	*/
-	
-	if(this->mem_lock_current > lim_saved_lock_current)
-	{
 		this->mem_lock_current = def_lock_current;
-		mcu::eeprom_write16b(addr_lock_current, this->mem_lock_current);
-	};
-	
-	if(this->mem_max_out_voltage > lim_saved_max_voltage)
-	{
 		this->mem_max_out_voltage = def_max_out_voltage;
-		mcu::eeprom_write16b(addr_max_out_voltage, this->mem_max_out_voltage);
-	};
-	
-	if(this->mem_min_out_voltage > lim_saved_min_voltage)
-	{
 		this->mem_min_out_voltage = def_min_out_voltage;
-		mcu::eeprom_write16b(addr_min_out_voltage, this->mem_min_out_voltage);
-	};
+	}
 	
 	this->restore();
 }
@@ -218,4 +172,22 @@ void logic::CfgMemory::restore(void)
 	this->min_out_voltage = this->mem_min_out_voltage;
 }
 
+uint8_t logic::CfgMemory::checksum(void)
+{
+	uint32_t cs = 0;
+	cs += (uint32_t)this->mem_btn_force;
+	cs += (uint32_t)this->mem_bmode;
+	cs += (uint32_t)this->mem_pot_mode;
+	cs += (uint32_t)this->mem_dsp_brigth;
+	cs += (uint32_t)this->mem_dsp_dimm;
+	cs += (uint32_t)this->mem_brake_force;
+	cs += (uint32_t)this->mem_max_hbrake_time;
+	cs += (uint32_t)this->mem_lock_current;
+	cs += (uint32_t)this->mem_max_out_voltage;
+	cs += (uint32_t)this->mem_min_out_voltage;
+	
+	return (uint8_t)cs;
+}
+
+
 /**** Private function definitions ****/
diff --git a/firmware/src/logic/cfg_mem.h b/firmware/src/logic/cfg_mem.h
index 522f757..97460a4 100644
--- a/firmware/src/logic/cfg_mem.h
+++ b/firmware/src/logic/cfg_mem.h
@@ -11,7 +11,7 @@ namespace logic {
 
 class CfgMemory
 {
-	protected:	
+	protected:
 	uint8_t mem_btn_force;
 	uint8_t mem_bmode;
 	uint8_t mem_pot_mode;
@@ -27,6 +27,7 @@ class CfgMemory
 	CfgMemory(void);
 	~CfgMemory(void);
 	
+	uint8_t cfg_good;
 	uint8_t btn_force;
 	uint8_t bmode;
 	uint8_t pot_mode;
@@ -42,6 +43,7 @@ class CfgMemory
 	void save(void);
 	void save_all(void);
 	void restore(void);
+	uint8_t checksum(void);
 };
 
 /**** Public function declarations ****/
diff --git a/firmware/src/main.cpp b/firmware/src/main.cpp
index a5f1edf..a29bbfe 100644
--- a/firmware/src/main.cpp
+++ b/firmware/src/main.cpp
@@ -29,19 +29,20 @@ int main(void)
 	// Read saved config
 	cfg_mem.init();
 	
-	#ifdef OVERRIDE_CONFIG
-	cfg_mem.btn_force = 0;
-	cfg_mem.bmode = 0;
-	cfg_mem.pot_mode = 0;
-	cfg_mem.dsp_brigth = 100;
-	cfg_mem.dsp_dimm = 50;
-	cfg_mem.brake_force = 100;
-	cfg_mem.max_hbrake_time = 1000;
-	cfg_mem.lock_current = 4200;
-	cfg_mem.max_out_voltage = 6500;
-	cfg_mem.min_out_voltage = 500;
-	cfg_mem.save_all();
-	#endif
+	if(cfg_mem.cfg_good !=1 )
+	{
+		cfg_mem.btn_force = 0;
+		cfg_mem.bmode = 0;
+		cfg_mem.pot_mode = 0;
+		cfg_mem.dsp_brigth = 100;
+		cfg_mem.dsp_dimm = 50;
+		cfg_mem.brake_force = 100;
+		cfg_mem.max_hbrake_time = 1000;
+		cfg_mem.lock_current = 4200;
+		cfg_mem.max_out_voltage = 6500;
+		cfg_mem.min_out_voltage = 500;
+		cfg_mem.save_all();
+	};
 	
 	uint8_t user_force = 0;