Some Electronic Circuit Designs Are Just Better Than The Others
There is no doubt that after so many years in this electronics repairing line I could say that not all electronics equipment have good circuit design. They varied in type and quality components used and also the circuit design. Some equipment tend to fail faster than the other brand. Here some examples of those failures in electronics equipment:
1) Fuse and Bridge Rectifier always blow (other brand of the same type of equipment does not have such problem)
2) EEprom or Flash Rom ICs data always corrupted and need original data to overcome this problem but to other design both ICs can retain the data- (practically last forever).
3) Secondary filter capacitors always bulge causing lots of problem but in other model the capacitors still looks new even after 10 years in service.
4) Horizontal output transistor (HOT) always go short circuit but to other design they are so robust. Even the flyback transformer already spilled out the epoxy due to overheat yet the HOT still tested good!
5) Switch mode power transformer primary winding always short circuit but in other equipment even if it already went through a high power surge, the primary winding was still perfect!
From the above we could know that the quality of components used and how the circuit was designed play an important part in determining how long the equipment will last. If you replaced with a cheap non branded e-caps you can expect the same fault will come back again in a very short time.
Is there a way to eliminate such problems? Yes there are and please read the below solutions:
1) Replace with good quality components
2) Putting in extra effort on the equipment such as by adding in extra heat compound or even bigger heat sink to eliminate the heat faster dissipated by the transistor/IC/diodes and etc. Some repair techs add in a small fan to cool the system. and usually the equipment will last longer under a cool environment.
3) Understand the circuit well so that you will know the weakness of the equipment. If the cap is 1000uf 16 volt always bulge then replace it with a good quality cap with the rating of 1000uf 25 volt.
4) Modification- There are repair tech that can modify a particular circuit to work even better than the original. There was a case where a particular Monitor HOT always burn. What he did was to replace a non polar capacitor across the existing electrolytic capacitor in the suppy line to the horizontal driver transformer. This prevents the HOT from blowing after using the Monitor for certain period of time.
If you had done some successful modification I would like to hear your success story-thanks.