This DC electronic load unit is in good condition. This HP 6050A and modules has been tested and works fine. Can be operated in constant current, constant voltage, and constant resistance modes. The 6050A 1800 Watt Electronic Load Mainframe along with the power modules are designed for test, evaluation, and burn-in of DC power supplies, batteries, and power components. The unit is suitable for bench use. The front panel keypad allows easy, repeatable, and reliable front panel control of the load when it is used manually. Front panel settings are remembered after AC power is removed. The front panel LCD meters indicate voltage, current, and power readings of the selected channel. Each module can operate independently in constant current (CC) mode, constant voltage (CV) mode , or constant resistance (CR) mode. In addition, each input can be turned on or off (open circuit) or short circuited. Features include built-in GPIB interface and built-in pulse generator, both standard. Pulse mode allows dynamic testing of power supplies and components, without giving the device under test time to heat up. The flexible pulse mode provides six triggering methods, allowing synchronization with a wide variety of events. A Save/Recall feature allows you to save up to 7 complete instrument setups, one of which can be saved in non-volatile memory so that it is recalled automatically at power-on. Also standard is GPIB read back of actual input voltage and current, and extensive protection and status reporting capability. The 6050A mainframe contains two cooling fans (one) whose speed automatically increases or decreases as the module temperatures rise and fall. This feature reduces overall noise level because the fans do not run at maximum speed at all times. Each load module can be individually controlled either via GPIB or locally via the front panel. Once a channel is selected or addressed, all subsequent commands go to that channel until another channel is selected or addressed. Operation of all models is similar, regardless of power ratings.