QuestionQUESTION: My Aiwa Colour TV, model No. TV-A2019, has developed audio problems.
1. The audio output from the speaker is high even when volume is set at level one. Audio output is constant for volume level 1 to around 16. Muting is possible on setting the volume level to zero.
Balance is also not working. Selecting only the right or the left speaker by using the balance control does not mute out the other speaker and there is audio output from both speakers. On setting the audio balance at the centre, the right speaker is much more louder that the left speaker.
3. Also the audio output sounds like mono though output comes from both the speakers.
4. Video is Ok.Remote control is also ok.
I can understand basic circuitry but trouble shooting has become a problem for me under the instant case. Please help.
ANSWER: greetings from virginia! it sounds to me that your EEPROM (electronically eraseable programmable read only memory) ic chip is bad. this small chip controls everything from volune control, channel storing, video settings and set up settings(vertical height, position, and tuner alignment settings)and more. if you order one, use exact model number and possibly serial number so you can get one already programmed for your set. otherwise it will have to be programmed at a shop where they have proper service equipment. good luck....
---------- FOLLOW-UP ----------
QUESTION: Thanks for the immediate response.
It seems the IC you referred to is the "TMP87CP28N-2C71" which is shelded by a metal box on the PCB. Found that the IC codes can be adjusted by entering the service mode using the remote control. Any help with the codes or ways to reset it?
Answerthat part number doesn't sound right. it should be an 8 0r 10 pin ic, unshielded and away from others towards the front of set. i don't have access to service literature since retirement, so i honestly don't remember the key sequence. resetting ic is impossible without an eeprom programmer which in your case won't do any good since the location that the stored data is corrupted or just dead there. as far as i know, once eeprom has failed, only cure is replacement. find a parts supplier where you are and tell them you need an eeprom for an aiwa (model, serial) and they should be able to find it easily as in parts list they list ic's by name and part number.
