Need help troubleshooting amplifier based on TDA2822

[maurycy]

I have built a small 1W amplifier based on the TDA2822 chip. Schematic is here:

schematic

I have made a mistake and connected 12V AC to the circuit (did not read the power adapter label carefully). About a second later, I heard a pop and then I disconnected the circuit. Well, it doesn't work now. I have inspected the board but do not see any obvious burn marks.

This amp was built from a kit since my electronic knowledge is very limited. Could somebody point me in the right direction what to check to determine what got blown?

Thanks

 

[Andy5112405]

Capacitor C1 and the TDA2822 are almost certainly fried.

 

[maurycy]

Thanks. I will replace the C1 with new one and I am waiting for TDA2822 replacement which I ordered "just in case". Will report back when I have that completed.

 

[maurycy]

Update: I have replaced the C1 and TDA2822 and the amp is working! TDA2822 was definitely fried as swapping them makes the amp not-functional. Did not want to bother checking the capacitor as it was a cheap replacement. Thanks for your help Andy.

 

[enigmaticEntity.]

It's a very portable amp, mine runs on 4*1600mAh 1.2V rechargables for days of "normal use" when I'm not using the wall supply. 4.8V is not a lot, but is OK for quiet-ish listening. Wall supply is 12V and can get as loud as any computer speakers.

Once I fried one using 5V at 20A from a PC power supply, still works but is like hooking up to a 2.5V source, that's how loud (soft) it goes before distortion. Scavanged another from a tiny radio and replaced. 3V radio isn't used anyway....and I did buy a fresh TDA from the electronics store

 

[maurycy]

I want to use mine as a headphone amp. The manual states that I should use 3V for use as a headphone amp but the enclosure I have only fits 9V battery. I guess with 9V, the output could be damaging to my ears if I crank the volume up.