Monitor rclbga at W8 @n- nedor pin 13 while apply- ing + .nd - 10 V at TPA. Voltage d pin 13 .hould b e + 1 V a n d - l V r 6 p c - tiwly.

A13U3 by substi- r 'e pan. Als

1389,10 ard feed- oh A'l3B13 thru

Replac€ Al3U2 in socker. Monitor wltage at pin 1 of W8 @nectff whi[6 apply- i n g + a n d - 1 0 V a t p i n 2 . Voltage at pin 1 should b€ + 10 V arü- l0 V re- spoctiwly-

Chsk BATIO ilitch @n- laqts and wiring,

Figure7-16. Ratio TroubleshootingTree.

't-35

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Image 194
HP Car 3490A manual Ratio TroubleshootingTree