HP HP-Bench-Briefs-1981-06-08 free download

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m . I -. 1 SERVl CE INFO R MATI0N FROM HEWLETT-PACKARD JUNE-AUGUST 1981 Logical Troubleshooting IN THIS ISSUE Logical Troubleshooting Transistor/Diode Cross Reference Service Notes New HP 1304A Display Power Supply spent. Availing yourself to the ex- The Information Funnel that the detector is really working) periences of others will make you and then to make measurements at more productive (and more Now we come to another considers- B,C, and D until the defective stage valuable!) tion in the information-seeking pro- is finally isolated. While this %erial cess. Once a decision has been method" works, the fastest approach If no one else has seen the problem, reached as to where a check or is to use "halfsplitting" technique. you must solve it yourself. At this measurement is to be made, there stage, apply the Rules of Logical still remains the related question of The main principle of half-splitting Troubleshooting. This consists of what type of check to make. You is that a check is made at the mid- "milking" the instrument for all must decide, for example, whether to point of the remaining part of the symptoms available. U e your eyes, s flip a switch, take a measurement or circuit that has not yet been ears and nose. Are lights lit? Read- replace a part. checked. outs active? Are there any signs of heat or broken components? Are The information funnel means mak- Looking back at Figure 1 we know there any abnormal sounds? Pops, ing the type of check that is most that there is no audio output (point hissing, hum? Is there a smell asso- appropriate to the size of the trouble E) and we suspect that a signal ciated with a particular area? Es- brackets at a given time. The d e is: exists at point A. (We know for cer- sence of carbon camp? The symptoms As you progress in locating a trou- tain that one output of the detector are next sorted by functions -try to ble, vary the type of memurement is ok because of the reading on he localize the fault to a particular you make in a specific order. Start signal strength meter.) Now what?? function. Many times this can be with front-panel checks, then make done by using switches on the front adjus