Computer hardware troubleshooting
- 2. INDEX INTRODUCTION OF COMPUTER HISTORY OF COMPUTER INTRODUCTION AND TROUBLESHOOTING OF CPU INTRODUCTION AND TROUBLSHOOTIN OF MONITOR AND KEYBOARD INTRODUCTION AND TROUBLESHOOTING OF MOUSE AND PRINTER INTRODUCTION AND TROUBLESHOOTING OF UPS
- 3. computer computer an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals.
- 5. Charles Babbage English inventor 1791-1871 taught math at Cambridge University invented a viable mechanical computer equivalent to modern digital computers
- 6. Babbage’s first computer difference engine built in early 1800’s special purpose calculator naval navigation charts
- 7. INTRODUCTION OF CPU A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.
- 8. BLOCK DIAGRAM OF CPU
- 10. No Power, Part 1 Active outlet? Using power strip or UPS? Turn computer off. Plug power cord into computer and power outlet. Power cord connected? Turn computer off. Plug power cord into different active wall outlet. Ensure power strip or UPS is turned on. Restart computer and return to start of this chart. Turn off power, disconnect power cord, and open the computer. No Power (Power LED is off) Y N Y N Y N No Power, Part 2
- 11. 2-4 3. No Power, Part 2 No Power, Part 1 System board have 5V Aux LED? Plug power connector into system board. N Plug in power cord. Power supply connected to system board? 5V Aux LED on? Replace power supply. 1. Press power button on. 2. Check for fan rotation. 3. Press power button off. Does fan spin? N N 1. Unplug power to all drives. 2. Remove all installed cards. 3. Press power button on. Does fan spin? Replace power supply. Y Y 1. Add drives back one-at- a- time to find faulty drive. 2. Add cards back one-at- a- time to find faulty card. Power on? Done Y N , No Power, Part 3 Y N Y N Y
- 12. NO Power, Part 3 No Power, Part 2 Drive power and data cables connected? N Loose or damaged components? Y N Reinstall cover and restart computer. Reseat drive power and data cable connectors. Y Reseat loose components and replace damaged items in the computer. Power LED on? Y N Replace power switch. Power LED on? Y N Replace system board. Done Done
- 13. Error Messages part 1 Power LED has no color showing. Computer is off. Power LED blinks green 1x/second. Normal suspend mode. Power LED glows red. CPU not installed/fetching code. Power LED blinks red 4x/second. CPU thermal shutdown. Power LED blinks red 1x/two or more seconds. Power supply crow bar. Beeps, CPU or Keyboard Lights, or POST error messages. Power and hard drive LEDs glow red. Riser board not seated. Num Lock LED flashing green. Memory error. Caps Lock LED flashing green. No video. Scroll Lock LED flashing green. System board failure, prior to video. Power LED glows green. Computer is on. Audible. 1L 3S. System ROM is bad; system is running in FailSafe Boot Block Mode. Audible. 2S. Power-ON successful. Continued on Page 2-10, Error Messages, Part 2. Notes: Short (S) and long (L) beeps will only be heard if the system has a speaker. LEDs will only function on PS/2 keyboards, not USB.
- 14. Num Lock blinking. System memory not present or incompatible. Unplug, open computer, and check memory modules. Ensure memory modules are correct type and that they match in size and speed. Cap Lock blinking. Video controller not present or incorrectly initialized. Ensure monitor is plugged in. Unplug, open computer, and check video card. Reseat card and ensure it is in the proper expansion slot. All keyboard LEDs blinking. ROM Failure. Create ROM Paq diskette and reload ROM. Scroll Lock blinking. System HW failure prior to video. Unplug, open computer, and check for physical damage. Ensure all cables and cards are seated. Look for burn marks or smoke. No beeps. HD and Power LED blinking. Riser not detected. Unplug, open computer, and check and reseat riser board. 2S Beeps. System Option not set. Select F1. If error occurs after reboot, unplug and open computer and check CMOS jumper setting. Part 2
- 15. The “Blue Screen” has appeared. The dreaded “Blue Screen of Death”. There’s not a lot to be done except to reboot the machine. If it keeps occurring, this is an indication of a major problem with the computer.
- 17. Block diagram of monitor Block
- 18. The picture does not appear. Check to make sure the signal cable is firmly connected in the socket. Check to see if the computer systems power is ON. Check that the Brightness Control is at the appropriate position, not at the minimum.
- 19. No Video, Part No video Beeps or flashing CPU or keyboard lights? Monitor LED on? Contrast and brightness turned up? Turn contrast and brightness up. , No Video, Part 2 Error Messages, Part 1 LED color? (note 1) Video adapter connected? (note 2) Monitor plugged in and turned on? Plug in and turn on monitor Reconnect monitor (note 3). Y N Y Y N NGreen Amber N N Video OK? Y Done Y Y Plug in, turn on, and return to Page 2-2, Initial Troubleshooting. Replace monitor. N
- 20. Adjust the H-Size, H-Phase or V-Size, V-Center controls. Check if the signal timing of the computer system is within the specification of the monitor The Screen is not synchronized. Check to make sure the signal cable is firmly connected in the socket. Check that the output level matches the input level of your computer. Make sure the signal timing of the computer system is within the specification of the monitor.
- 21. The screen is shaking Move all objects that emit a magnetic field, such as a motor or transformer, away from the monitor. Check if the specified voltage is applied. Check if the signal timing of the computer system is within the specification of the monitor. The screen is too bright or too dark 1. Check if the Brightness or contrast control is at the appropriate position, not at the maximum or minimum. 2. Check if the specified voltage is applied 3. Check if the signal timing of the computer system is within the specification of the monitor. 4. Especially, check the horizontal frequency
- 23. Block diagram of mouse
- 24. Keyboard Symptoms Typical symptoms associated with keyboard failures include the following: No characters appear on screen when entered from the keyboard. Some keys work, whereas others do not work. A Keyboard Error—Keyboard Test Failure error appears. A KB/Interface Error—Keyboard Test Failure error appears. An error code of six short beeps is produced during boot up (BIOS dependent). The wrong characters are displayed. An IBM-compatible 301 error code appears. An Unplugged Keyboard error appears. A key is stuck.
- 27. Block diagram of printer
- 28. Printer is not working First, make sure that the printer is on. When a printer is on, it should have some light or LED (usually green) indicating it's receiving power. Your printer should have two cables connected to it: the power cable and the data cable. Make sure the power and data cables are connected to both the printer and computer. If you do not have any indicator light, make sure the printer is connected to a working power outlet by verifying each end of the power cable. Next, press the printer power button. If after doing the above steps, the printer still does not display a power status indicator light, you have a serious printer issue and we suggest contacting the printer manufacture for repair or replacement.
- 32. Block diagram of mouse
- 33. ISSUE: Mouse Cursor Does not Relocate Smoothly SOLUTION: If your mouse cursor does stagnate smoothly then the most likely cause will be either dust in the mouse sensor or dust on the mouse surface, be it a mouse mat or work desk. Make sure that you provide the mouse a comprehensive cleansing making certain just to use a clean cloth and no chemicals which are most likely to trigger even more problems. ISSUE: Mouse Not Working At All SOLUTION: Your mouse not working at all could possibly be from a range of issues. The mouse not working may be as an outcome from a loose hookup, defective electrical wiring, a defective USB or PS/2 port or a defective IR cordless receiver. Some wireless gadgets (and some wired) will need a mouse motorist to be installed for correct use. If all this falls short then, as usual, disconnect and power up your mouse and COMPUTER. .
- 34. ISSUE: Mouse Guideline Too Slow Or Too Quickly SOLUTION: There’s only actually one option for this and it’s a software configuration problem. This can quickly be repaired by visiting Control board) Mouse) Tip Options Tab. Modification the pointer speed to the desired level by moving the slider up or down till it feels more comfortable. ISSUE: Issue With Double Click SOLUTION: As above this will most likely be a software setup problem and can be taken care of by going to Control Panel) Mouse) Buttons tab. Modification the double click speed and examination it to a comfortable click rate level.
- 36. Freezing and crashing THREE FINGER SALUTE - CTRL-ALT-DEL TO CLOSE UNRESPONSIVE PROGRAMS. IF CTRL-ALT-DEL DOES NOT WORK, HOLD IN POWER BUTTON ON CPU UNTIL IT SHUTS DOWN, THEN RESTART . HAVE YOU INSTALLED ANY NEW SOFTWARE? TRY REMOVING IT TO SEE IF IT IS THE CAUSE. TRY REMOVING IT TO SEE IF IT IS THE CAUSE IF YOU CANNOT GET IN TO UNINSTALL, BOOT IN SAFE MODE - PRESS F8 WHILE REBOOTING - THEN TRY TO UNINSTALL SHUT DOWN AND UNPLUG COMPUTER FOR 5 MINUTES, THEN TRY AGAIN
- 38. KEEP IT RUNING REBOOT PERIODICALLY. KEEP AWAY FROM CHALK DUST & MAGNETS . EMPTY RECYCLE BIN . DEFRAGMENTERFR EVERY OTHER MONTH - START - PROGRAMS - ACCESSORIES - SYSTEM TOOLS - DISK DEFRAGMENTER . CLEAN OUT THE TEMPORARY INTERNET FILES FOLDER. FROM YOUR BROWSER GO TOOLS- INTERNET OPTIONS AND USE THE DELETE FILES OPTION. IT’S ALSO A GOOD IDEA TO DELETE COOKIES AND LOCALLY CACHED FILES IN YOUR BROWSER PERIODICALLY.