JVC TV AV-20N1P No Sound problem

[Butingting]

I have a JVC TV Model AV-20N1P/AV-20N1P-PH, the problem is "No Sound". I already replaced the LA4285 IC (Power Amplifier with DC Volume control) but it's still have no sound. Any idea how to solve it? Also need schematic diagram for this TV.

[Guest]

Does the speaker work?
Do the headphone jacks work correctly? (nothing jammed in them, dirty contacts)
Are you getting a dc input into the IC from the volume control?
Do the coupling capacitors work?
What happens if you input a sound into the IC? If you get sound out, check the coupling capacitor, then the FM Decoder IC.

Let us know what you find.

[Butingting]

Thanks bro, I will check it right away!
Any idea where I can download free schematic for JVC TV AV-20N1P?

[zalds]

find a good diagram and look for the mute ckt of the audio section........try to hang the mute pin on the ic of audio amp. if its not present somrtimes its the input transistor of the audio stage some times the transisor are the muting drive open the base and try to hear any sound coming out if not again try to ocate sound if section i think thats the last thing ull find the problem

[Butingting]

I checked that there was no DC in going to the Volume IC (0.01V), it should be around 16V. Now I need is the schematic diagram to see where the supply voltage is coming from. I tried to manual trace the board, but It will be not good enough.

[Butingting]

Pls. help me to get JVC TV AV-20N1P or JVC TV AV-20N1PPH service diagram

[sparky]

I had a look but could not locate the manual but the manual number is 56048 in the year 2000 and the c.d rom disk number is SML200010 for those with jvc c.d rom disks. I have some but not this one.
It may be an idea to check around the lopt for an o/c resistor if a supply is missing.
_________________
If in doubt pull the plug out.

[stelling5]

bro.

The B+ of Amplifir in your tv locatd in Main Power supply and Flyback Transformer check that area. there 2 B+ in tv amplifier check that 2.

thats all.