BASIC TROUBLESHOOTINGo 8237A DMA controllero 8253 Timero 8259A Programmable Interrupt Controllero Keyboard InterfaceSTEP ONEPOKER ONPower Cords and Switches1. Ensure that the power cord is plugged into theback of the computer2. Ensure that the power cord is plugged into aproperly grounded wall outlet. (Use a lamp thatyou know is in working order, and check that theoutlet has power.)3. Ensure that the power cords for any currently-attached external devices (printer, etc.) thathave separate power cords are plugged intoproperly grounded wall outlets.4. Insert the Service Diagnostic diskette into driveA. Use a working copy of the original diskette.Make a back-up copy on another computer, ifnecessary, but do not use a diskette that has nobackup. The possibility exists that a problemcould result in the loss of the software.5. Turn ON any attached external devices that haveseparate power cords and switches (unless thedevice installation instructions specified thatthe device be turned on after the computer).6. Turn ON the computer power. Turn the volumecontrol and brightness to maximum.2-2
