You have to select the file to erase hold the erase button and when "ERASE" blinks in the display you have to press the erase button one more time. Do this for each file you wants to erase.
You can recover deleted files with asoftech data recovery software. get the software from link belowAudio Recorder Recovery SoftwarePlease be noted that your voice recorder memory should show as a drive letter in your explorer, if not, you need to take out your memory card and connect using a card reader, or plug-in to card reader slot if there's any on your computer.You may check out this memory card recovery tutorial also
The nearest you will get is the service manual.
Dowmload the service manual and follow the dissasambly and reassambly instructions to the letter, otherwise it will not work correctly and the timing will be out.
https://elektrotanya.com/panasonic_sa-ak20.pdf/download.html
Try disconnecting all of the speakers except the left and right main speakers. If it works, check the wiring at the back of each speaker to make sure there aren't any shorts between the terminals. Better yet, just inspect the terminals both at the audio unit and the backs of the speakers. Stray strands of wire reaching across to the other terminal or exposed wire on the other side are a common problem.
If you have that all cleaned up and still have the error, you may have shorted transistors in the output amp of one of the channels, very likely the subwoofer. This may be caused by shorted speaker wiring, or the amp may have failed on its own. In either case, you would have to replace both of the output transistors for that channel (they may be built into a power amp module, in which case the module must be replaced). This requires soldering skill, and the knowledge to identify the transistors and check them with an ohmmeter. Most of the time, it's a basic job for any skilled electronic technician. (I did run into one model that would have required two days of disassembly labor just to get at the failed transistors - I told the customer that wasn't designed for service and he would be better off buying something different to replace it.)
Original CD Stereo System comes with remote control and that does not need to connect. Moreover, buttons and switches are also given for manual use. If you want to use universal remote control, please specify make and model.
