Teledyne Tablet Accessory T803 Manual De Usuario

Troubleshooting and Service 

Teledyne API T803 CO2/O2 Analyzer Operation Manual 

188 

 

11.2. USING THE INTERNAL ELECTRONIC STATUS LEDS 

Several LEDs are located inside the instrument to assist in determining if the 
analyzer’s CPU, I

2

C bus and relay board are functioning properly. 

11.2.1. CPU STATUS INDICATOR 

DS5, a red LED, that is located on upper portion of the motherboard, just to the 
right of the CPU board, flashes when the CPU is running the main program loop.  
After power-up, approximately 30 to 60 seconds, DS5 should flash on and off.  If 
characters are written to the front panel display but DS5 does not flash, then the 
program files have become corrupted.  If after 30 – 60 seconds neither the DS5 is 
flashing or no characters have been written to the front panel display, then the 
CPU is bad and must be replaced. 

 

 

11.2.2. RELAY PCA STATUS INDICATORS 

There are sixteen status indicator LEDs located on the Relay PCA.  Some are not 
used on this model. 

11.2.2.1. I

The most important is D1 (which indicates the health of the I

2

C bus).   

D1 

(Red) 

 I

2

C  bus Health 

(Watchdog Circuit) 

Continuously ON 

or 

Continuously OFF 

Failed/Halted CPU 
Faulty Motherboard, Keyboard or Relay PCA 
Faulty Connectors/Wiring between Motherboard, 
Keyboard or Relay PCA 
Failed/Faulty +5 VDC Power Supply (PS1) 

If D1 is blinking, then the other LEDs can be used in conjunction with DIAG 
Menu Signal I/O to identify hardware failures of the relays and switches on the 
Relay PCA.   

07276B DCN6418