Laptop Model: HP Pavilion 15 440 G1 TPN-Q129
Board Number: DA0U83MB6E0 REV:E
Fault: Does Not Turn On Or Power On
Repair Process :
There was no current when
connected to the power supply, and the indicator light on the HP interface did
not light up. After disassembling the machine, it was found that the
motherboard showed no traces of welding or tampering.
The test found that the
protection and isolation are normal. When I tested the standby voltage, there
was no 3V or 5V. I thought it was a problem with the standby part. Open
the drawing and see that this machine has 3V5V after triggering. Before
triggering, it only has linear 3V5V. The actual measurement is normal.
No 3V5V found. Turn on signal S5_ON from EC's 101
PIN.
After pressing the switch, the
S5_ON signal is not sent. Check the working conditions of EC KB9010. The power
supply +3VPCU is normal. The clock is sent from the CPU.
The reset ECRST is generated
internally by the EC. LID_EC# is high and normal. There is a detection signal
on the AD_TYPE adapter. There is no voltage. The normal detection signal
voltage should be about 2V. It is initially judged that the EC 9010 is damaged.
I took out the programmer, flew the wires, and programmed the EC
9010. I found that the programmer could not identify the chip model of the EC
9010. It was judged that the EC 9010 chip was damaged. Some people said that
9010 and 9012 are universal.
When I opened the spare
parts box, there was no Found the 9010 EC chip, there is only one 9012 A4 and
one 9012 A3. Thinking that it can be used universally, I soldered the
brush first!
Two KB9012, one A3 and one A4,
just like this made me toss around again. It seems that this may be the reason
why this board cannot be used universally.
I had no choice but to order the chip and order 2 KB9010s. I
soldered one first, fixed the flying wires, and programmed the power on the
motherboard.
After brushing, plug in the
power supply and the power indicator light turns on. The measured detection
signal AD_TYPE voltage is 1.1V. Press the switch and the current trots all the
way to about 0.5-0.6-0.55.
When connected to the screen,
there is no backlight or image, but a faint light can be seen on the screen.
Black shadows flashed and flashed, and the same thing happened when I shined a
flashlight on it. It seemed that there was something wrong with the
motherboard.
I have used an oscilloscope to
measure the memory, but after flashing the BIOS program, the problem is still
the same. It seems to be a display problem. Even after changing the screen, the
same phenomenon persists.
After another round of
measurements, it was found that among the three sets of data on the screen
signal, a clock pin has a voltage of about 1.2. The power supply on the screen
cable interface is normal.
The screen detection signal
PCH_EDIDCLK PCH_EDIDDATA has no signal, and the BLON_CON backlight has no
voltage when it is turned on. After carefully looking at the drawing,
I found that this machine is
designed with two specifications of screens that can be optional. The 17PIN of
the screen interface can be used to define an EDP screen or an LVDS screen.
This is achieved through resistors R230 R233 respectively. What is installed on
this machine is The LVDS screen is equipped with an R230 resistor.
Looking for the source, I came to an RTD2132R
chip. The function of this chip is to convert the EDP signal into an LVDS
signal.
This chip is relatively rare. There is a similar
chip on the ASUS machine that has been repaired in the past. The model is
2136R. 2136R is 48PIN.
The chip is 32PIN. After checking the working
conditions of the chip, it was determined that the chip was damaged.
After replacing it, it starts up normally.
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