Teledyne M300EM operation manual 8:Relay Board Control Devices, Function, In Socket

Troubleshooting & Repair Teledyne API – Technical Manual - Model 300E Family CO Analyzers

13.5.5.RELAY BOARD

The relay board PCA (P/N 04135) can be most easily checked by observing the condition of the its status LED’s on the relay board, as described in Section 13.1.4.3, and the associated output when toggled on and off through signal I/O function in the diagnostic menu, see Section 13.1.3.

1.If the front panel display responds to key presses and D1 on the relay board is NOT flashing then either the wiring between the Keyboard and the relay board is bad, or the relay board is bad.

2.If D1 on the relay board is flashing and the status indicator for the output in question (heater power, valve drive, etc.) toggles properly using the signal I/O function, then the associated control device on the relay board is bad.

∙Several of the control devices are in sockets and can be easily replaced.

∙The table below lists the control device associated with a particular function:

Table 13-8: Relay Board Control Devices

FUNCTION	CONTROL
	DEVICE
Wheel Heater	K1
Bench Heater	K2
Spare AC Control	K3
IZS Valves	U4
IR Source Drive	U5

IN SOCKET

Yes

Yes

Yes

Yes

No

The IR source drive output can be verified by measuring the voltage at J16 with the IR source disconnected. It should be 11.5± 0.5 VDC.

290 04288D DCN5752