Motherboard /Logic Board Repairing
How we repair the Logic Board?
All laptops and Mac books have inbuilt or externally removable motherboards. Once the motherboard of your laptop or the logic board of your Mac system gets errors, its assumed that the motherboard is faulty and needs to be replaced. We as technical experts, first diagnose the cause of the error and then identify the solutions to that problem. If we find the fault in the motherboard/logic board, we will replace the logic board, else, the defective parts are identified and replaced. Next the spare parts are pre-heated for defective component identification. The board will be cleaned by an ultrasonic cleaner for removal of all accumulated liquids or dust or other such materials.
Booting Problems
Boot sequence is the foundation for the booting of a system. POST does not rely on the type of the Operating System. In fact, there is no need for an Operating System to be installed for the POST to run. The reason behind is that system is handled by BIOS and not the Operating system. This test checks the basic devices present for accurate working of the peripheral devices and other hardware elements like processor, storage devices and memory. Computers booting happens only after the POST becomes successful. Problems such as windows,hanging during startups or otherwise can appear after the POST. If the POST is unsuccessful, the device shows an error of some kind.
POST (Power on Self Test)
An acronym for a diagnostic test performed for computers running after, it has been powered on. The concept of POST is not limited to, computers, but also, to other medical equipments.
SYMPTOMS OF THE POST (POWER ON SELF TEST)
POST symptoms can come in various forms such as
- Errors in flashing LED's,
- Audible beeps,
- Error messages on the monitor, and so on.
POST Codes get displayed only when the /a monitor is plugged in. If the messages are something other than POST Codes, which come as a wrong display, then the motherboard or the video card is faulty.
Complaints faced by customers on a technical perspective
Blue Screen -Blue Screen errors arise when Microsoft Windows encounters a critical error from which it cannot recover. This results from either slow level software (or Drivers) or crashing of faulty hardware. Blue screen errors occur when your computer's hardware or issues with hardware driver's software's becomes faulty. At times, it can also arise due to low-level software running in the Windows Kernel.
When does the Blue Screen Error Occur?
A blue screen error occurs when the system Windows encounters a "STOP ERROR". The failure causes the Windows to either crash or stop working. The only thing that would keep the system running is the Restart option. But be careful! The data loss could happen as the system could not save the files in use or data in open mode.
The Blue Screen Error automatically helps Windows to create a "mini-dump" file that contains all information about the crash and saves it to your disk. You can easily view this file to identify the cause of the error. Blue Screen Errors could differ from system to system. In Windows System, and previous versions, blue screen looks like a terminal screen with all information displayed. In Windows 8 and 10 Blue Screen errors become simpler."Your PC ran into a problem and needs to restart. We're just collecting some error info and then we will restart it for you. (0% Complete)."
Systems by default in Windows automatically, restart whenever it encounters a blue screen error. You can disable the automatic restarts from the Windows Control Panel.
Disable Automatic Reboot after Blue Screen Errors
Right Click on the Computer icon and Choose Properties. Windows 7 or Vista users will take you to the systems properties screen and click on Advanced System Settings. With the Advanced tab selected, you'll want to click on Settings Button under "Startup and Recovery". Next Uncheck the Option Automatically restart under the System failure section.
Troubleshooting Beep Codes
Computers get beeps codes, when either the system gets faulty due to failure of the booting or POST errors and or flashing LED's. Such beeps come to be known as BEEP CODES. This comes along with BIOS (Basic Input Operating System). If you hear beep codes after the computer is turned on then that means the motherboard has encountered a problem.
Solving BEEP CODES
- Power on the computer or restart if already on.
- Listen to the beep codes when it begins to boot. Restart if the beep codes still exist.
- Figuring out the manufacturing defect with the motherboard.
DELL LAPTOP BEEP CODES
1 | BIOS ROM checksum in progress or failure | System board failure, covers BIOS corruption or ROM errors |
2 | No Memory (RAM) detected | Memory or Memory slot failure |
3 | Chipset Error (North and South bridge error, DMA/IMR/Timer error), Time-Of-Day Clock test failure, Gate A20 failure, Super I/O chip failure, Keyboard controller test failure | System board failure |
4 | Memory read / write failure | Memory failure |
5 | Real Time Clock (RTC) power fail | CMOS battery failure |
6 | Video BIOS test failure | Video subsystem failure |
7 | CPU Cache test failure | Processor failure |
8 | LCD/LED | LCD/LED failure |
1 - 2 | No video card detected | Reseat the video card |
1 - 2 - 2 - 3 | BIOS ROM checksum error | |
1 - 3 - 1 - 1 | DRAM refresh error | Reseat the memory modules |
1 - 3 - 1 - 3 | 8742 Keyboard Controller error | Reseat the keyboard connector |
1 - 3 - 3 - 1 | Memory defective or not present | Reseat the memory modules |
1 - 3 - 4 - 1 | RAM failure on line xxx | Reseat the memory modules |
1 - 3 - 4 - 3 | RAM failure on data bits xxx of low byte on memory bus | Reseat the memory modules |
1 - 4 - 1 - 1 | RAM failure on data bits xxx of high byte on memory bus | Reseat the memory modules |
DELL BIOS POST CODES
CPU register test in progress | |
02 | CMOS read/write test failed |
03 | BIOS ROM checksum bad |
04 | 8254 programmable interrupt controller failed |
05 | DMA controller initialization failed |
06 | DMA page-register test failed |
08 | RAM refresh verification failed |
09 | Starting first-64K RAM test |
0A | First-64KB RAM IC or data line bad |
0B | First-64KB RAM odd/even logic bad |
0C | First-64KB address line bad |
0D | First-64KB parity error |
10 | Bit 0 bad in first 64KB |
11 | Bit 1 bad in first 64KB |
12 | Bit 2 bad in first 64KB |
13 | Bit 3 bad in first 64KB |
14 | Bit 4 bad in first 64KB |
15 | Bit 5 bad in first 64KB |
16 | Bit 6 bad in first 64KB |
17 | Bit 7 bad in first 64KB |
18 | Bit 8 bad in first 64KB |
19 | Bit 9 bad in first 64KB |
1A | Bit 10 bad in first 64KB |
1B | Bit 11 bad in first 64KB |
1C | Bit 12 bad in first 64KB |
1D | Bit 13 bad in first 64KB |
1E | Bit 14 bad in first 64KB |
1F | Bit 15 bad in first 64KB |
20 | Slave DMA register bad |
21 | Master DMA register bad |
22 | Master interrupt-mask register bad |
23 | Slave interrupt-mask register bad |
25 | Loading interrupt vectors |
27 | Keyboard-controller test failed |
28 | CMOS RAM battery bad |
29 | CMOS configuration validation in progress |
2B | Video-memory test failed |
2C | Video initialization failure |
2D | Video-retrace failure |
2E | Searching for a video ROM |
30 | Switching to video ROM |
31 | Monochrome operation OK |
32 | Color (CGA) operation OK |
33 | Color operation OK |
34 | Timer-tick interrupt in progress (or bad) |
35 | CMOS shutdown test in progress (or bad) |
36 | Gate A20 bad |
37 | Unexpected interrupt in protected mode |
38 | RAM test in progress or high address line is bad |
3A | Interval timer channel 2 bad |
3B | Time-of-day test bad |
3C | Serial-port test bad |
3D | Parallel -port test bad |
3E | Math co-processor test bad |
3F | Cache-memory test bad |
HP laptop keyboards caps light is blinking and I can't see anything into Screen?
HP Laptop problems in a notebook LED or when the beep code occurs.
BEEP CODES or LED or Problems
An LED or Beep Codes indicate a basic function in the system is unable to start. Basic functions such as reading memory, displaying videos, or unable to send information to a hard drive when needed alerts you with beep codes of LED Flashes.
Common problems that tend to cause your LED's and or Beep codes to beef up. These problems usually pop up when either memory related failures or extreme heat affects the system. This can also arise due to dust or sands from accumulating on your cooling pads in the system.
Recommended steps to perform when the BEEP Codes flashes:
- Perform a hard reset or forced reset on a notebook computer. Before you begin the process, turn the computer or tilt over for a battery compartment door. If no battery compartment is found, then use the steps in the sealed or non removable battery section.
- Removing dust from cooling areas on the Notebook. As time passes, dust may have ago at the cooling vents of your system. Systems can overheat or fail due to excessive dust accumulating on the cooling-pads of the system. It's recommended to remove all dust or sands that have accumulated onto the system.
- Wearing of eye protection kits can cause the air to blow out of the vents. It's not a must to open the notebook to clean the dust with canned compressed air.
- Next after cleaning of the vents, restart the system. If the computer starts normally, cheers lest proceed the next step.
- Write down, the LED Codes and /Beep codes.
- Steps to write the Led blinking or beep patterns. Press the power button to turn on the computer.
- The computer's socket has an LED. Note whether the light next to the power socket blinks ad note down its condition—off, blinking or, constantly on.
- Notice for the caps light or number key lock's lights. If the lights blink, count the number of times the light blinks between pauses.
- Write these down and remember the blinking patterns. Then proceed to the next.
- HP Laptop Blank Screen LED ERROR Codes
HP Laptop Blank Screen LED ERROR Codes
Code type | Number of Blinks or Beeps | Component Being Checked | Condition | Possible solution(s) |
AC power adapter LED | Constantly on | Power adapter | OK. Power is being supplied | None. The power adapter is likely not the problem |
AC power adapter LED | Constantly off | Power adapter | Power is not being supplied | Try a different power outlet. Replace power adapter. |
AC power adapter LED | Continuous blinking | Power adapter | Insufficient power | Try a different power outlet. Replace power adapter. |
Caps Lock/Num Lock | 1 | CPU | CPU not functional | Reseat replace CPU.Service |
Caps Lock/Num Lock | 2 | BIOS | BIOS corruption failure | Restore BIOS from onboard backup (jumpers) Service |
Caps Lock/Num Lock | 3 | Memory | Memory module error not functional | Reseat memory modules (see next section). Test memory from UEFI or BIOS. Replace bad memory modules. Service |
Caps Lock/Num Lock | 4 | Graphics | Graphics controller not functional | Service |
Caps Lock/Num Lock | 5 | System board | General system board failure | Service |
Caps Lock/Num Lock | 6 | BIOS | BIOS authentication failure | Restore BIOS from on-board backup (jumpers) Service |
Beep | Varies | Varies | Varies | Reseat the memory modules (see next section). Service For more detail on the exact code, search the Internet for "beep code" and the manufacturer of your BIOS - such as AMI or Award. |
All another laptop beeps code error
Beepcodes | Error |
AMI (long+short beeps) | |
1x short | DRAM refresh failure |
2x short | Parity circuit failure |
3x short | Base 64K RAM failure |
4x short | System timer failure |
5x short | Process failure |
6x short | Keyboard controller Gate A20 error |
7x short | Virtual mode exception error |
8x short | Display memory Read/Write test failure |
9x short | ROM BIOS checksum failure |
10x short | CMOS shutdown Read/Write error |
11x short | Cache Memory error |
1x long, 3x short | Conventional/Extended memory failure |
1x long, 8x short | Display/Retrace test failed |
AWARD (long+short beeps) | |
1x long, 2x short | Indicates a video error has occurred and the BIOS cannot initialize the video screen to display any additional information |
Repeating (Endless loop) | Memory error. Bad memory or bad connection |
1 Long, 3 Short | Video adapter failure. Bad video adapter or memory |
High freq. beeps (while running) | CPU is overheating. CPU fan failure |
Repeating High, Low beeps | CPU failure. Bad processor |
Any other beep(s) | RAM problem |
IBM (long+short beeps) | |
No Beeps | No Power, Loose Card, or Short. |
1 Short Beep | Normal POST, computer is ok. |
2 Short Beep | POST error, review screen for error code. |
Continuous Beep | No Power, Loose Card, or Short. |
Repeating Short Beep | No Power, Loose Card, or Short. |
One Long and one Short Beep | Motherboard issue. |
One Long and Two short Beeps | Video (Mono/CGA Display Circuitry) issue. |
One Long and Three Short Beeps. | Video (EGA) Display Circuitry. |
Three Long Beeps | Keyboard / Keyboard card error. |
One Beep, Blank or Incorrect Display | Video Display Circuitry. |
Apple (different tones) | |
Error Tone. (two sets of different tones) | Problem with logic board or SCSI bus |
Startup tone, drive spins, no video | Problem with video controller |
Powers on, no tone | Logic board problem |
High Tone, four higher tones | Problem with SIMM |
New BIOS-Chips |
IBM (long+short beeps) | |
No Beeps | No Power, Loose Card, or Short. |
1 Short Beep | Normal POST, computer is ok. |
2 Short Beep | POST error, review screen for error code. |
Continuous Beep | No Power, Loose Card, or Short. |
Repeating Short Beep | No Power, Loose Card, or Short. |
One Long and one Short Beep | Motherboard issue. |
One Long and Two short Beeps | Video (Mono/CGA Display Circuitry) issue. |
One Long and Three Short Beeps. | Video (EGA) Display Circuitry. |
Three Long Beeps | Keyboard / Keyboard card error. |
One Beep, Blank or Incorrect Display | Video Display Circuitry. |
Apple (different tones) | |
Error Tone. (two sets of different tones) | Problem with logic board or SCSI bus |
Startup tone, drive spins, no video | Problem with video controller |
Powers on, no tone | Logic board problem |
High Tone, four higher tones | Problem with SIMM |
New BIOS-Chips | |
PHOENIX (different intervals) | |
1-1-1-3 | Verify Real Mode |
1-1-2-1 | Get CPU type |
1-1-2-3 | Initialize system hardware |
1-1-3-1 | Initialize chipset registers with initial POST values |
1-1-3-2 | Set in POST flag |
1-1-3-3 | Initialize CPU registers |
1-1-4-1 | Initialize cache to initial POST values |
1-1-4-3 | Initialize I/O |
1-2-1-1 | Initialize Power Management |
1-2-1-2 | Load alternate registers with initial POST values |
1-2-1-3 | Jump to UserPatch0 |
1-2-2-1 | Initialize keyboard controller |
1-2-2-3 | BIOS ROM checksum |
1-2-3-1 | 8254 timer initialization |
1-2-3-3 | 8237 DMA controller initialization |
1-2-4-1 | Reset Programmable Interrupt Controller |
1-3-1-1 | Test DRAM refresh |
1-3-1-3 | Test 8742 Keyboard Controller |
1-3-2-1 | Set ES segment to register to 4 GB |
1-3-3-1 | 28 Auto size DRAM |
1-3-3-3 | Clear 512K base RAM |
1-3-4-1 | Test 512 base address lines |
1-3-4-3 | Test 512K base memory |
1-4-1-3 | Test CPU bus-clock frequency |
1-4-2-4 | Reinitialize the chipset |
1-4-3-1 | Shadow system BIOS ROM |
1-4-3-2 | Reinitialize the cache |
1-4-3-3 | Auto size cache |
1-4-4-1 | Configure advanced chipset registers |
1-4-4-2 | Load alternate registers with CMOS values |
2-1-1-1 | Set Initial CPU speed |
2-1-1-3 | Initialize interrupt vectors |
2-1-2-1 | Initialize BIOS interrupts |
2-1-2-3 | Check ROM copyright notice |
2-1-2-4 | Initialize manager for PCI Options ROMs |
2-1-3-1 | Check video configuration against CMOS |
2-1-3-2 | Initialize PCI bus and devices |
2-1-3-3 | Initialize all video adapters in system |
2-1-4-1 | Shadow video BIOS ROM |
2-1-4-3 | Display copyright notice |
2-2-1-1 | Display CPU type and speed |
2-2-1-3 | Test keyboard |
2-2-2-1 | Set key click if enabled |
2-2-2-3 | 56 Enable keyboard |
2-2-3-1 | Test for unexpected interrupts |
2-2-3-3 | Display prompt "Press F2 to enter SETUP" |
2-2-4-1 | Test RAM between 512 and 640k |
2-3-1-1 | Test expanded memory |
2-3-1-3 | Test extended memory address lines |
2-3-2-1 | Jump to UserPatch1 |
2-3-2-3 | Configure advanced cache registers |
2-3-3-1 | Enable external and CPU caches |
2-3-3-3 | Display external cache size |
2-3-4-1 | Display shadow message |
2-3-4-3 | Display non-disposable segments |
2-4-1-1 | Display error messages |
2-4-1-3 | Check for configuration errors |
2-4-2-1 | Test real-time clock |
2-4-2-3 | Check for keyboard errors |
2-4-4-1 | Set up hardware interrupts vectors |
2-4-4-3 | Test coprocessor if present |
3-1-1-1 | Disable onboard I/O ports |
3-1-1-3 | Detect and install external RS232 ports |
3-1-2-1 | Detect and install external parallel ports |
3-1-2-3 | Re-initialize onboard I/O ports |
3-1-3-1 | Initialize BIOS Data Area |
3-1-3-3 | Initialize Extended BIOS Data Area |
3-1-4-1 | Initialize floppy controller |
3-2-1-1 | Initialize hard-disk controller |
3-2-1-2 | Initialize local-bus hard-disk controller |
3-2-1-3 | Jump to UserPatch2 |
3-2-2-1 | Disable A20 address line |
3-2-2-3 | Clear huge ES segment register |
3-2-3-1 | Search for option ROMs |
3-2-3-3 | Shadow option ROMs |
3-2-4-1 | Set up Power Management |
3-2-4-3 | Enable hardware interrupts |
3-3-1-1 | Set time of day |
3-3-1-3 | Check key lock |
3-3-3-1 | Erase F2 prompt |
3-3-3-3 | Scan for F2 keystroke |
3-3-4-1 | Enter SETUP |
3-3-4-3 | Clear in-POST flag |
3-4-1-1 | Check for errors |
3-4-1-3 | POST done--prepare to boot operating system |
3-4-2-1 | One beep |
3-4-2-3 | Check password (optional) |
3-4-3-1 | Clear global descriptor table |
3-4-4-1 | Clear parity checkers |
3-4-4-3 | Clear screen (optional) |
3-4-4-4 | Check virus and backup reminders |
4-1-1-1 | Try to boot with INT 19 |
4-2-1-1 | Interrupt handler error |
4-2-1-3 | Unknown interrupt error |
4-2-2-1 | Pending interrupt error |
4-2-2-3 | Initialize option ROM error |
4-2-3-1 | Shutdown error |
4-2-3-3 | Extended Block Move |
4-2-4-1 | Shutdown 10 error |
4-3-1-3 | Initialize the chipset |
4-3-1-4 | Initialize refresh counter |
4-3-2-1 | Check for Forced Flash |
4-3-2-2 | Check HW status of ROM |
4-3-2-3 | BIOS ROM is OK |
4-3-2-4 | Do a complete RAM test |
4-3-3-1 | Do OEM initialization |
4-3-3-2 | Initialize interrupt controller |
4-3-3-3 | Read in bootstrap code |
4-3-3-4 | Initialize all vectors |
4-3-4-1 | Boot the Flash program |
4-3-4-2 | Initialize the boot device |
4-3-4-3 | Boot code was read OK. |
Using System Software or USB Flash Drive
- Disconnect all external devices like hard drives, memory cards, flash drives, printers and scanners from your Mac Book Pro.
- Leave the keyboard and mouse alone. If the system or unit is on, turn it off.
- Insert your OS X Installation kit into the Mac Book Pro. If you have a system software, USB flash drive, plug it into an open USB Port.
- Restart your computer and press the D Key before the Gray screen appears to display the hardware test.
- Select the language as per your need and press Enter/Return key on the Keyboard or the right arrow to start the diagnosis.
How to enter the BIOS Command in A Mac Book Pro?
Loading the Open Firmware on Start-Up
Mac Book's Open Firmware, act as the key to the BIOS command in the Mac Book Pro. In order to access the Open firmware, you must/should shutoff/shutdown the computer. Next we need to switch it on Again by holding down the Command, Option, 0 and F keys simultaneously for booting the Open Firmware. This Open Firmware is two-toned (i.e. it doesn't provide extensive prompts as in the PC mother boards). If all is working well the screen showing an OK word is shown. Else the parts need to be replaced.
Displaying RAM Configurations
Memory is the crux to each document or the likes of a user for retrieval later on. The Open Firmware allows you to display the RAM Configurations on your Mac book Pro through your OS/Operating System and performs the diagnostic tests. The RAM can be accessed by "dev./memory. Properties" and is displayed according to the need of SDRAM cartridges installed on the unit.