Thursday, December 29, 2011

Dell Inspiron 14R Spill

This Dell 14R had a water/coffee spill and blew some parts and pads
from the laptop 
This image shows the resistor PR12 after removed from board. Shown here
before cleaning

This image shows how it should look, and the original view.
This image shows how the repair had to be done.  Part of the pad was still visible, and the hole pad had enamel
removed to allow connectivity to the pad and trace.

DV7 Power On By Pass - TIP

The DV6000 and DV9000 series has a bypass jumper that you can short to turn on the unit without having to connect the power on button.

Now the DV7 also has a method also.  this way you don't have to disconnect from the frame and makes it prone to breakage or scratching the plastic.

Toshiba L455D - Powers On Then Off

Toshiba L455D Blink On then Off Light.
Power light functions normally. Charge light functions normally.
Does not run. Does not post.

Turns on then shuts off. The unit powers on then after a few seconds- shuts off.

This is was caused by a shorted MOSFET PQ10 that exhibited a full short 0Ω Since they were in a pair formation, both were replaced so the current level would be balanced.  The cost is so low, that it was not a consideration. Two AO4466 replaced with two AO4468 mosfets which were available.  AO4468 is out of production, but were found on an HP DV6000 near the Maxim [MAX8734/PU10] quad output power distribution chip.             (PQ31/PQ32 on DV6k)

The coil PL3 was cracked in half, was not exactly sure if the coil would be defective, but the nature of coils is to push current within the electromagnetic field, so if the field is open the electrons may not go forward, tools did not allow the ability to verify. So it was replaced. 

(When in doubt, replace)

Please No Questions regarding this repair- They won't be answered
It was simply found by finding the shorted MOSFET. This is only a reporting blog for other to have an idea where to find the problem, not to fix it for them.  Use logic in following the electrical path.  You can not learn if you are always shown the answers.

Note: No Video issues on this model is caused by the nVidia GPU, not this area. This is the power-in section. Do not reflow the whole GPU at one time, because it not anchored by epoxy. Do half, allow time to cool, then other half.

Monday, December 19, 2011

DV5-2155dx - No Video, Blinking lights on topside

I will only report how I fixed it, not answer specifics related to why/how/what or "where can I get parts" questions, because I simply don't have the time to reply to the requests.

This DV5 came in with no video display.

The problem was a coil L6002 to the right of the GPU shield.

The coil and/or pad cannot handle the 'bounce' current that flows through. Taking the coil out of the circuit path eliminates that problem.  Small inset image shows where the coil was and the old path of the circuit.
Larger View Shows coil location