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Released in 2006, identified by model number PP20L for e1505

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How to fix my motherboard?


Please help me repair the motherboard of my Dell Inspiron E1505 laptop. The laptop doesn't start when I push the power button.

Here it is what I tried so far:

- start it without battery in, only using power adapter

- start it without any RAM

- start it using a known good power adapter

- CMOS reset

But my laptop is dead. No beep, no LEDs, nothing.

The power adapter is putting out 19.8V.

I have the service manual, I have even the schematics of entire laptop. I opened it looking for any obvious signs of damage on the motherboard. But no luck. I checked if DC power socket is firm in place. It is.

I am quite proficient at electronics, but not too familiar with laptop repair. Perhaps somebody can tell me where to start measuring the basic voltages (3.3V, 5V, etc). I can take photos of motherboard if that will help identify strategic points for measurements.

Thank you.

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Hi, what caused the laptop to be dead? Also can u pls post some pics of the motherboard near the power supply input in focus?


Thank you for answering, John.

The power adapter central pin (data pin for that Dallas gizmo) broke and of course my battery was not charged anymore, plus the usual Dell BIOS rant (you don't have a genuine PA bla bla) popped on. I didn't care about not charging the battery, it's dead anyway, so I eventually took it out. I worked like that for a month or so, then one morning my laptop didn't boot at all. As I already said, no LEDs, no clicks, nothing. PA voltage is OK, 19.8V.

I took some detail photos of the entire motherboard. I've put them at

Please let me know what to do next.


John, please let me know if I understand it right.

You want me to check for a stand-by voltage on SATA or DVD connector?? How so?


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Well fixing a motherboard is never a piece of cake but you can learn it and check the motherboard on your own here's how-

First you need to know what parts a motherboard has

Parts of a motherboard

Let’s know about it’s parts and features before going to Motherboard Repairing

Parts of Motherboard

1.CPU –

It is also called the processor, the CPU works as the computer’s brain. It is responsible for fetching, decoding, and executing program instructions as well as performing mathematical and logical calculations.The processor chip is identified by the processor type and the manufacturer. This information is usually inscribed on the chip itself.If the processor chip is not on the motherboard, you can identify the processor socket as socket 1 to Socket 8, LGA 775 among others. This can help you identify the processor that fits in the socket.

2.RAM –

Random Access Memory, or RAM, are the computer chips that temporarily store dynamic data to enhance computer performance while it is on. Here all the active programs and data are loaded so that any time the processor requires them, it doesn’t have to fetch them from the hard disk. Random access memory loses its contents once power is turned off. Though hard disks and flash memory does not require a power source to retain data. When a computer shuts down properly, all data located in RAM is returned back to permanent storage on the hard drive or flash drive. At the next boot-up, RAM begins to fill with programs automatically loaded at startup, a process called booting. Later on, the user opens other files and programs that are still loaded in the memory.

3.BIOS ( Basic Input/ Output System )

BIOS stands for Basic Input/Output System. BIOS is a “read only” memory, a low-level software that controls the system hardware and acts as an interface between the operating system and the hardware. It is more known as just drivers. BIOS is considered as the link between the computer hardware and software in a system. Motherboards include a small block of Read Only Memory (ROM) which is separate from the main system memory used for loading and running software. The system BIOS is a ROM chip on the motherboard used during the startup routine (boot process) to check out the system and prepare to run the hardware. The BIOS is stored on a ROM chip because ROM retains information even when no power is being supplied to the computer.

4. CMOS Memory –

Motherboards also include a small separate block of memory made from CMOS RAM chips which are charged by a battery (known as a CMOS battery) even when the PC’s power is off. This prevents reconfiguration when the PC is powered on.

5. Cache Memory –

Cache memory is a small block of high-speed memory (RAM) that enhances PC performance by pre-loading information from the (relatively slow) main memory and passing it to the processor on demand. Most CPUs have an internal cache memory (built into the processor). This can be supplemented by external cache memory fitted on the motherboard. This is the Level 2 or secondary cache.

6. Expansion Bus –

An expansion bus is an input/output pathway from the CPU to peripheral devices made up of a series of slots on the motherboard. Expansion boards (cards) plug into the bus. PCI is the most common expansion bus in a PC and other hardware platforms. Buses carry signals such as data, memory addresses, power and control signals from component to component.

7. Chipsets –

Chipset is a group of small circuits that coordinate the flow of data to and from a PC’s key components. These key components include the CPU itself, the main memory, the secondary cache, and any devices situated on the buses. A chipset also controls data flow to and from hard disks and other devices connected to the IDE channels.

8.CPU Clock –

The CPU clock synchronizes the operation of all parts of the PC and provides the basic timing signal for the CPU. A 200 MHz CPU receives 200 million pulses per second from the clock. A 2 GHz CPU gets two billion pulses per second. Similarly, in any communications device, a clock may be used to synchronize the data pulses between sender and receiver. A “real-time clock,” also called the “system clock,” keeps track of the time of day and makes this data available to the software. A “time-sharing clock” interrupts the CPU at regular intervals and allows the operating system to divide its time between active users and/or applications.

9. Switches and Jumpers –

Switches are small electronic switches found on the circuit board that can be turned on or off just like a normal switch. Jumper pins are small protruding pins on the motherboard. A jumper cap or bridge is used to connect or short a pair of jumper pins. When the bridge is connected to any two pins, via a shorting link, it completes the circuit and a certain configuration has been achieved.

Also let me tell you what are the signs of a faulty motherboard-

Signs Of A Faulty Motherboard :

Find out symptoms when the motherboard is faulty so that you can go for Motherboard Repairing

1.Computer does not boot. instead, you get a beep code.

2.Random computer crashes causing General Protection Fault error messages, Illegal Operations, Fatal Exceptions, etc.

3.Computer randomly reboots.

4.Motherboard doesn’t recognize/show peripherals plugged in

5.Peripherals will stop working for a few seconds or more

6.Slow boot ups could indicate that your motherboard is going bad, though it could be other components as well

7.Computer won’t recognize flash drives or monitor sometimes shows strange lines

8.The Motherboard doesn’t POST (Power On Self Test).

9.Burning smell or burn marks anywhere on the motherboard itself.

Now here's how you can test your motherboard

How to Test your Motherboard :

It is important to check what the problem really is before you start Motherboard Repairing.

Visual hardware check

A common cause of motherboard issues or failure blown capacitors. Check the top of each capacitor to see if it is bulging, even slightly, or if the capacitor is leaking, which is an indication the capacitor is blown. For the CPU, a visual check will require you to remove the CPU from the computer. Once the CPU is removed, check for bent pins on the side that is inserted into the motherboard. If you find a bent pin, that is likely to be the cause of issues with the CPU and computer.It may be possible to replace a bulging or blown capacitor, but it will require precision soldering to install a new capacitor. Bent pins on a CPU can be bent back into place.If a visual check shows there are no obvious visible issues, you should use a software utility or hardware tools to diagnose the problem.

Software and Hardware solutions

Below are a couple software programs designed to test your computer’s motherboard and CPU.

Hot CPU Tester – Great tool for testing a motherboard and CPU. Easy to run and use to look for failures with your computer. Hot CPU Tester also includes a burn-in feature for new computers or computers with a new motherboard or CPU.Intel Processor Diagnostic Tool – If you have an Intel processor the Intel Processor Diagnostic Tool is a great free utility for

Intel Processor Diagnostic Tool – If you have an Intel processor the Intel Processor Diagnostic Tool is a great free utility for testing a variety of Intel processors.

PC-doctor – A fantastic, but not cheap, Solutions often used for service centers and technicians to diagnose computer hardware issues including motherboard issues.

Ultra-X – Another great collection of products that can help test computer hardware, including the motherboard.

Reasons Why Your Motherboard Is Not Working :

Try to diagnose the reason before you jump to any conclusion while Motherboard Repairing ,

1.Not Enough Power

Check first if the powers are available. motherboards have not just one power connection, but two. There is a main 20-to-24-pin connector, and a second 4-pin connector hidden away by the processor socket, though the 4-pin may instead be an 8-pin, particularly on mobos built with overclocking in mind. You have to check to make sure that both are in use. watch out if both plugs are properly matched with the correct power supply cords.

2. Improperly installed Components

Components can cause a motherboard problem if not properly installed.Sometimes your computer does not get through POST (a self-testing mechanism employed by PCs during boot-up) or even turn on. it may be due the processor, video card, and RAM. Improper seating of the video card and RAM are the most likely sources of your problems. Examine the video card, and make sure that it’s evenly seated across the width of the PCI-Express slot. The RAM slot has two plastic wings that should snap over the sides of each stick of memory. These should be standing upright 90 degrees from the motherboard’s surface, and securely inserted around the tabs found on each side of your RAM sticks. The pins and the slot on the processor and motherboard must be properly lined up. Once inserted, the processor should sit flat inside the socket’s surface. The processor’s heatsink should also attach firmly.

3. A Short circuit

Motherboards are filled with capacitors and soldered connections that route data and power from one part of the board to another. As you may have noticed, the motherboard is held aloft from the PC case by a series of screw-in “standoffs” that are about a quarter-inch thick. These exist because the motherboard can short if it makes contact with other metallic components. A motherboard experiencing a short may not get through POST or may boot but then crash at random. A failure to pass the POST process is the most frequent symptom, but the other situations can occur even if only occasional contact is made between the motherboard and the case. Check that you used the stands that keep the mobo above the case, and ensure that any unsupported portions of the motherboard haven’t bent towards the case’s interior. Also, check that all internal wires are properly shielded with a rubber or plastic exterior.

4. No Case Power Button Connection

The power button on a computer’s case connects to the motherboard through a small, thin two-pin wire. Connecting the power button can be difficult. Unlike so many other motherboard connectors, which are designed to make improper installation impossible, the power button connector usually is labeled only with plus and minus symbols.

You’ll need your motherboard’s manual, and possibly a magnifying glass to solve this issue. You’ll need the manual to confirm where the power button connector goes, and you (might) need the magnifying glass to properly align the connection with the pins. If you can’t find your manual, your motherboard’s manufacturer should have a PDF version of it on the company’s site. Just search for your motherboard’s model number.

5.BIOS hardware incompatibility :

Motherboards ship from the factory with a BIOS or UEFI operating system that can handle modern hardware, but any hardware released after it ships is not guaranteed to work. Even new processors that fit into the motherboard’s CPU socket may not be compatible out of the box. You’ll first have to re-install whatever old hardware you removed, both to confirm the issue, and to boot your computer. Once you do so, you can boot your computer, go to your motherboard manufacturer’s website, and find the latest BIOS/UEFI version. Install it, and then try installing your new hardware again.

Some Common Problem & Solutions

Here are two common problems and its fixes for you. Learn this simple steps for Motherboard Repairing.

Motherboard repairing solutions

1.Blue Screen – Follow these steps to get rid of blue screen caused by motherboard

Switch off and isolate your power supply to the system.

Open the cabinet cover.

Locate the RAM slots.

Unfasten the locks that appear on both sides.

Remove the RAM

Clean the RAM copper connectors with dry clean cloth.

Blow air into the connectors.

Re-insert the RAM.

Fasten the locks.

Put back the cabinet cover

Power up the system.

If the symptom persists replace the RAM.

2.Itching Fan Sound- Follow these steps to get rid of fan sound

Switch off and isolate the main supply

Open the cabinet cover

Look around and find the processor on the motherboard.

Try to rotate the fan mounting screws in the anti-clockwise direction.

At a certain position, the screws hold tight to the processor and any loose fitting ends.

Put back the cabinet cover.

Connect and switch on the computer.

Hope this helps.


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My next suggestion would be to clean the motherboard with isopropyl alcohol as I see there are a lot areas with rust or what seems like rust. And then once u have done that, plug in your power supply and check the voltage at the sata connector and also at the dvd connector for voltages. Also check if there is anything shorting the power supply input. Write back on what u did.

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Hi, as I see from the picture (btw, awesome clarity on the pics) the dvd connector is soldered to the motherboard and there are pins from which voltages can be measured. Check this link,

Same to do on the sata connector. Also trace the voltage from the input pin. Hope this helps.


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