Re: HP ProBook 4510s Short Circuit

Going to get a local guy to replace several suspect transistors (Q1054, Q1055, Q1056) on this motherboard. He's been repairing laptops for over a decade. Don't have the money to buy a good rework station since I didn't win the MegaMillions jackpot.

Hopefully that will get things running.

One final question. The schematics show Q1055 as a PMV65XP. But the markings on the PMV65XP on the board, there are several, don't match. Those markings look like WM9, but the closest I found was a NXP Semiconductors PMV65XP marked...

Got an HP ProBook 4510s as a stripped down shell from my local Goodwill Store. Was able to easily get it working. Unfortunately, there was a loose screw in the machine. While using it, I closed the lid to put it to sleep then turned it over to read the model number off the bottom of the machine. When turned right side up, the machine would not come to life. Seems the screw shorted something out. Found it stuck against the metal frame on the bottom of the board that holds the heatsink on. My iGo power adapter shuts down every time I plug it in to the motherboard. Hard to check the board with no...

Re: HP Monitor Mash-up

Current capacitor replacement plans (subject to change due to availability). All from Digi-Key.

Power board:
Su'scon SH 125C 47uF 25V--> [URL="http://search.digikey.com/us/en/products/UBT1H470MPD1TD/493-4507-1-ND/2650347"]Nichicon BT 47uF 25V[/URL] Larger than original but looks like it will fit. Due to location on the high side of board when installed and near large heatsinks, keeping 125C rating seems sound.
Samxon GK 470uF 25V --> [URL="http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&KeyWords=P12388-nd"]Panasonic...

Re: HP Monitor Mash-up

Checked a couple of the fuses near the LVDS cable and found them to be good. Checked the resistance of the transistors on BOTH of the logic boards. The results follow. And a picture.

1907w Logic Board: (Problem)

Q105
S-G 1.38 M
S-D 1.4 M
G-D 5.06 K

Q106
C-B 4.5 M
C-E 4.49 M
B-E 14.84 K

Q103
S-G 290
S-D 145.6
G-D 380

L1908w Logic Board: (Working)

Q105
S-G 2.6 M
S-D 1.68 M
G-D 9.72 M...

Re: HP Monitor Mash-up

I think the LCD panel is probably OK. When connected to the L1908w logic board, the board that came with the panel, the proper message about no video connected is displayed. Only when I try it with the logic board from the 1907w do I get the white screen. All the power and control for the panel comes thru the logic card.

The Samxons are BD, GK, and KM.
The Su'scons are SE, SH, and SK.

I picked up an HP w1907 LCD display with the 2 second to black problem at my local Goodwill outlet store. Took it apart looking for bad caps but found no obvious problems. Tested the monitor again and found an all white screen. Playing around with it, I discovered that reversing the top two CCFLs make the backlight work until power save mode kicked in. Noticed later that the LVDS cable had a small tear in it. Thought that was the cause of the all white screen, but found out later it probably isn't.

So I picked up an HP L1908w display at the same store a few days later, planning...

Re: New Members - please post your introductions here

Hello.