BT2025 IC (TEA2025 IC) Shorted To Ground
Fault Symptom: front panel power indicator light blinking & no sound output
This symptom simply indicates problem in Power Section hence I have opened the speaker from backside & pulled out the circuit for further troubleshooting.
Surprising! No transformer inside.
On visual inspection nothing found suspicious I turned back the PCB and found rectifier diode (look like someone have tried to repair the unit before)
I have started the fault finding and found all these diodes are shorted while tested with using multimeter on continuity mode.
I have checked surrounding components found ok but have in one doubt about this IC in power section near fuse because it gets very HOT.
I have googled but not found any data about this IC. So decide to take a chance to check the effect by replacing the diode. Hence I have replaced all the four diodes.
After powering “ON” the unit I have seen the LED power Indicator Light is ON and it is not blinking. So I have connected the speakers to the mobile phone still there is no output. So my doubt about that IC again leads me to that section. I powered off the speakers and touched that IC still it is very hot to touch.
I am bit confused what to do Now because without that IC DATA it is difficult to find equivalent also.
So I have put the unit beside. After finishing another work in the morning I have again took this unit for repair in the evening with refreshed mind.
I have started tracing the circuit. On testing the power regulator IC voltage on pin no.1 I/P voltage showing .6V instead of 12V DC. (This regulator is supply 5V to audio amplifier on IC pin no. 16) so I powered OFF the unit and checked this IC with multimeter in continuity testing mode I found this regulator IC is short.
Further traced up to the audio amplifier IC and on testing continuity on the supply pin of audio amplifier IC it shows short with Ground so for confirmation I have removed the IC from the PCB and tested again. When removed the IC I found burnt mark on the PCB.
Replaced the IC and powered the speaker yes this is my final attempt and I did it.
I have now connected the speaker and now it is working. For full fill my curiosity about that 8 Pin IC Heating in power section. I have touched the IC & found it is Normal Now no heating.
This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.
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