This service manual of the old video cassette recorder VT-LC50EM is very good readable even the tiniest numbers (i.e. IC-pins). The circuits are very clear. Many details of the schematic are very good described but in GERMAN language. Many schematic details - but complete at all. Common background information of several details are enclosed and physical knowledge of the TFT liquid crystal display for example. The manual lacks PCB drawings. If you understand german I would recommend this manual for you.
Text excerpt from page 7 (click to view)
INSERTING THE BUTTON-TYPE BATTERY
Note: The lithium battery is a critical component (Type No.: CR2025 Manufactured by Panasonic.) It must never be subjected to excessive heat or discharge. It must therefore only be fitted in equipment designed specifically for its use. Replacement batteries must be of the same type and manufacture. They must be fitted in the same manner and location as the original battery, with the correct polarity contacts observed. Do not attempt to re-charge the old battery or re-use it for any other purpose. It should be disposed of in waste products destined for burial rather than incineration.