diff --git a/apsct_lib.py b/apsct_lib.py
index 6eb00df0a25cc44530364096bd17f9ccd52b5eca..e306a62ad7e5adb04d6bceaa2c76c415624b23af 100644
--- a/apsct_lib.py
+++ b/apsct_lib.py
@@ -26,7 +26,7 @@ else:
 
 I2CBUSNR = 5
 sleep_time = 0.15
-
+DEBUG = False
 
 class ApsctClass:
     #
@@ -96,6 +96,9 @@ class ApsctClass:
             self.power(False)
 
     def check_apsct(self):
+        #
+        # Check voltages, temp and lock on APSCT 
+        #
         result = self.sensors.check_values()
         if self.frequency == "200MHz":
             self.pll_200.read_lock()
@@ -129,11 +132,12 @@ class PllClass:
         # Write Byte to the PLL
         #
         pll_rw = 0x00  # 0 for write, 1 for read
-        stri = "Write to address : 0x{1:{fill}2x} value  0x{0:{fill}2x}".format(wr_data, reg_address, fill='0')
-        print(stri)
+        if DEBUG:
+            stri = "Write to address : 0x{1:{fill}2x} value  0x{0:{fill}2x}".format(wr_data, reg_address, fill='0')
+            print(stri)
         self.dev_i2c_pll.write_bytes(0x06, 0x2C)
+        rd_bytes = self.dev_i2c_pll.read_bytes(0x06, 1)
         if DEBUG:
-            rd_bytes = self.dev_i2c_pll.read_bytes(0x06, 1)
             stri = "IO expander wrote 0x{0:x}, read 0x{1}".format(0x2C, rd_bytes[1])
             print(stri)
         data = (reg_address << 9) + (pll_rw << 8) + wr_data
@@ -188,6 +192,7 @@ class PllClass:
         #
         # Set registers on the PLL
         #
+        print(f"Setup PPL {self.frequency}")
         self.dev_i2c_pll.write_bytes(0x07, 0x00)
         if self.frequency == '160MHz':
             self.dev_i2c_pll.write_bytes(0x03, 0x08)
@@ -367,17 +372,18 @@ class ApsctSensors:
         #
         # return result, True when OK, False in case of error
         #
+        print("Check power sensor values")
         result = True
         self.read_all_voltages()
         self.read_temp()
         for pwr in self.power_supplies:
             expected = APSCT_I2C.PWR_VOUT[pwr]
-            if 0.9*expected > self.voltages[pwr] > 1.1*expected:
+            if not (0.9*expected < self.voltages[pwr] < 1.1*expected):
                 result = False
-                print(f"Error {pwr} expected {expected} V read {self.voltages[pwr]} V")
-        if 15 > self.temperature > 50:
+                print(f"Error: {pwr: <9} expected: {expected} V read: {self.voltages[pwr]:4.2f} V")
+        if not (15 < self.temperature < 50):
             result = False
-            print(f"Error temperature read {self.temperature} °C")
+            print(f"Error temperature read {self.temperature:4.2f} °C")
         return result
 
     def read_voltage(self, input_channel=0):
@@ -394,7 +400,7 @@ class ApsctSensors:
         if DEBUG:
             stri = "Word to select sens input is 0x{0:x}".format(channel_select_word)
             print(stri)
-        sleep(0.1)
+        sleep(0.2)
         self.dev_i2c_sensor.write_bytes(channel_select_word, 0xB8)
         sleep(0.5)
         ret_ack, ret_value = self.dev_i2c_sensor.read_last_reg(3)
@@ -407,8 +413,9 @@ class ApsctSensors:
             steps = (int(ret_value, 16) & 0x1FFFFF) >> 6
             voltage = one_step * steps
             voltage = ((4.7+2.2)/2.2)*2*voltage
-            string = "Voltage sens line {1} is {0:.4f} V".format(voltage, input_channel)
-            print(string)
+            if DEBUG:
+                string = "Voltage sens line {1} is {0:.4f} V".format(voltage, input_channel)
+                print(string)
         return voltage
 
     def read_temp(self):