Question about laptop schematic

[merkin]

Here's the schematic:
http://lqv77.com/download/294/

I want to know what the pink boxes represent.

For example on page 28 of the schematic, there are pink boxes (or squares) and each one is numbered (NO.xx).

Perhaps they are "optional componants"...since for this example the models(inspiron 1420) laptop's webcam is an optional, and on page 28 it seams componants regarding the webcam are the ones with pink boxes.

Thoughts anyone?

Thanks in advance.

[b700029]

My guess is editor's notes. There are others without the No.xxx notation too.

[merkin]

Hey man,
Thanks for all your input.

The reason I ask is because of the other thread you responded to...

...I was checking out ebay and found a listing for a used inspiron 1420 http://www.ebay.com/itm/280896426635...#ht_500wt_1027

Except my inspiron 1420 does not have a webcam, but the ebay listing does have one. Figured it would be a plus if I can fix my current brightness issue and also get a webcam too.

I ripped open my inspiron already and looked for the pcb footprints for webcam compatibility.

I found the silkscreen print for inductor "L1" but the footprint must be underneath the metal sheilding right next to the label. And the shielding is soldered in place,

Then I looked for R1 and R3, and also Q74 and Q75. And also U1 hex inverter.
Found R1, R2, and R3, but in the schematic R3 is listed twice (just do a search in the schematic and you will see). Perhaps my motherboard is different revision than the schematic.

Think I am gonna bid and take the chance anyway. If webcam dont work, oh well at least the lcd brightness should work again.

Thanks again. I will post back if it works. Fingers are crossed.

Please dont bid me up

[b700029]

The webcam is a standard USB type webcam, just needs +5V/GND and the data pair. You could short across R1 and R3 to make a direct connection, but L1 is a common-mode choke probably installed to minimise interference on the data pair.

The other thing it needs is +5V, and that's what that circuit with Q75/Q74 is doing, switching the power via a GPIO on the chipset (page 17), but R604 can be used to bypass it and always enable power to the webcam. Otherwise you can just tap into the +5V_RUN rail somewhere.

U1 might be bypassed by R616 too, it looks like an option to invert mic's clock signal depending on the model installed.

I can't find the second R3.

[merkin]

Well you can see why I came to the assumption that the "pink boxes" are for optional components.

Originally Posted by b700029

I can't find the second R3.

Its R1 not R3, sorry 'bout that.

[asliyucegsm]

thank you friend

[merkin]

Replaced with exact OEM replacement.

Also the replacement came with integrated webcam and it also WORKS!

Thanks again.

[b700029]

That means there's no changes required to the laptop itself to accommodate the webcam option. All the circuitry is already there on the mobo.

Just posting this as a note that might help someone in the future.