The owner of this amp told me that the last moment of this amp was that he saw smoke oozing out from the amplifier and therefore I did not intend to apply power again to the amp lest I do more damage inside.
After opening the amp I went straight to test the transformer to see if it is okay…sure it has survived the ordeal.
Next I scanned around the circuit board and I noticed one component which has a catastrophic failure-as you know you don’t need to test a component with this kind of failure. Your eyes are good enough test equipment.
The two components happened to be TDA2030A: they were sharing the same heat sink so I removed them from the circuit together.
I applied power to the amp and I noticed the output voltage is still too low, the transformer is rated(13x2) therefore I was expecting around 18 vdc(13X1.414) but was too low.
So I suspected there must be another shorted component not yet picked up.
I switched off the power and touched on the components around the circuit looking for any component which is hotter than usual and I bumped on another component (i.c) which was very hot to my finger.
This must be the culprit, after checking it I found it was also a TDA2030A.
I removed it from the circuit and the voltage went up to (+-18 vdc) and I concluded that there is no more shorted component on the circuit.
The underside of the board has three darkened area where the i.c were installed which was further evidence that they must have been shorted.
I replaced the three TDA2030A and the amplifier came back to life.
Afterwards I searched for the datasheet of this i.c TDA2030A to check for its specifications and I noted that it is a 14 Watts HI-FI- audio amplifier and uses dual VCC(+-) hence why I was getting(+-18 vdc) on my meter.
I also found that it has other applications and I was particularly interested on its application as a crossover filter, a complete 3-way 60 Watt active loudspeaker system as shown in the diagram below.
I am a fun of do it yourself (D.I.Y) and this is definitely my next project thanks to Contek Microelectronics Co, Ltd.
Thank you guys
Let meet in the next class