Teledyne manual 5.5Major Internal Components, Maintenance, Model 7300A, Power, Analog, Preamp

5 Maintenance Model 7300A

Table 5-1: Self Test Failure Codes

Power

0OK

15 V Failure

215 V Failures

3Both Failed

Analog

0OK

1DAC A (0–1 V Concentration)

2DAC B (0–1 V Range ID)

3Both Failed

Preamp

0 OK

>0 Amplifier failure high offset (number is a code that pinpoint which gains are at fault).

Detector

0OK

1Failed (open filament, short to ground, no power.)

2Unbalance (deterioration of filaments, blocked tube)

5.5Major Internal Components

All internal components are accessed by unbolting and pulling open the rack assembly, removing the front cover, as described earlier. The major internal component locations are shown in Figure 5-3, the cell block is illustrated in Figures 5-2/5-3, and the fuse receptacle is shown in Figure 5-1.

The 7300A contains the following major internal components:

•Customer Interface PCB (Power Supply on bottom surface)

•Preamp PCB (Contains Microprocessor)

•Front Panel PCB (Contains Displays)

5 digit LED meter

2 line, 20 character, alphanumeric, VFD display

See the drawings in the Drawings section in back of this manual for details.

5-4 Teledyne Analytical Instruments