COMMON FAILURE MODES

 

I. +/- 15 volt amplifier power supply voltages low. Voltages should be no less than 14.7 volts.

 

A. Symptoms

1. Ray will call you and tell you one or more elements in a single rack has no output or a reduced output. Do not rely on Ray. Check front panel meter on control chassis to verify output current.

2. One or more elements in a single rack are inhibited. Check led on top of amplifier.

B. Solutions- most of the time the +15 volt, 9 amp power supply is beginning to fail.

            1. Try to adjust supply voltages with amplifiers operating.

            2. Replace Control Power Supply Chassis- a spare chassis resides in RM 104

            3. Fix faulty Control Power Chassis so you have a spare next time.

 

II.  A single amplifier failure.

             

            A. Symptoms

1. Ray will call you and tell you an element has no output. Do not rely on Ray. Check front panel meter on control chassis to verify output current.

                        2. Desired reference is ok. Check on front panel meter.

3. Amplifier may indicate that it is inhibited by led on top of amp.

4. Check RMS overcurrent is ok. Check RMS O/I status light on Control Chassis front panel. Light should be on if ok.

5. Check load connections and current monitor connection to Control chassis

 

            B. Solutions

1. If you want to test further, swap input connector and load leads with the amplifier next to the subject amp.

2. Change amplifier.

 

III. No reference at input to Amplifier.

 

            A. Symptoms

1. Ray will call you and tell you an element has no output. Do not rely on Ray. Check front panel meter on control chassis to verify output current.

2. Check Reference to suspect element on front panel meter. Reference will be very close to zero in this case.

3. Check corresponding Camac DAC output. Value should approximate the requested current value.

4 Check Connections between CAMAC Crate and Control Chassis.

5. In case of Dipole elements make sure the operator is using correct database device.

            B. Solutions

                        1. If no DAC output, replace CAMAC Card.

                        2. Fix connections if bad, etc.

 

IV. Amplifier Output oscillates.

           

A. Suspect MADC or RMS O/I card. MADC channels fail, and RMS O/I cards are new and can cause this problem.

 

Please note:

 

I have never mentioned control cards within the control chassis or the bulk supply. This is because these devices have not failed in 12+ years. This does not mean they won’t.

 

                       

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