M4800 Owner's Thread

@unnoticed

 

Well, I got my lid, and now it's time to get to work on replacing the board, replacing the lid and transplanting the graphics CPU and RAM to the new board and hoping for the best... Well there's no backlight going to my LCD panel even though there's content on display. Is something wrong with the cable or my board?

The other thing I noticed is that there's no magnet for the eDP lid... But I can't tell if it's that being the cause. Both panels work in my Zbook so the panels are fine. Is it possible there's a gone fuse, or is it possible that I could've gotten a dud lid with the eDP cable?

 

Delta fan: has more fins, with the same spin amount (speed) it pushes more hot air out
AVC fan: has less fins, so hence less air push (debatable)

Delta fan con: after extensive use or without likes to chirp* (makes chirp noise then spins up)
AVC fan con: NO CONS, never chirps*

now not related to your question but I think others will find following information useful.

there are two brands of sinks.

Auras
AVC


I have ran few rudimentary experiments and can safely say that evaporation rates are far better on
AURAS sinks. making them SINK of CHOICE! for overclocking.

I can run Intel core i7 4900qm 4.9 ghz four cores. (4ghz auto shutdown)
this is in tandem with Delta fan that was serviced and oiled.


AVC branded Heatsinks do well on sub 4700 and all i5 core duos.

I am inclined to think reason for inferiority is either gas or quality of alloy used.

does this help anyone?



nice thread to all!

make sure you check my mod for GPU upgradeers (AMD WX4150) this will save you from MELTING your speakers.

 

There is only one Delta fan that I know of.

There are many AVC fans under the same part number, I've received multiple fans that do not fit each other.
The impeller might be higher ie taller so the housing is taller to fit the taller impeller. The shaft might be thicker or thinner.
The fans are also programmed differently and behaves completely different from each other.
Due to the lack source code from bios and EC I can't tell if this is part of EC or communication between EC and the fan.
a. AVC thinner with thinner shaft
b. AVC thinner with thicker shaft
c. AVC thicker with thinner shaft
d. AVC claiming outputting 12cfm at the same A (amp) rating as the other AVC fans. I have not gotten my hands on one of these.

I have never had my hands on any of the SUNON branded fans because these are reserved for dual core configurations.
But even then sometimes I've seen used M4800 in dual core configuration for sale with Delta fans

My current configuration is that I use the AVC fan housing of the a. type and fitted it with a c. type impeller.
Its a good compromise of the quiet nature of the AVC fan compared to the Delta but with extra push of the thicker impeller.
Temps do matter between the AVC and Delta fans but the EC firmware do not treat the fan curves that way.
The way the Delta fan promises higher cfm is by using higher A (ampere) equals higher rpm and being loud and annoying.
Yes there is a firm flow of air pushing out of the vent even being cool to the touch but the EC firmware doesn't care about that it will still keep the Delta fan revved while the AVC fans will do a lower rpm and still do fine.
I love the Dell workstations by the serviceability over Lenovo but I miss the complete control over fan speeds I had with tpfancontrol or nbfc Notebook fan control.
I have another M4800 with the delta fan and same bios revision, although a different cpu from mine (4940mx) and that one has the 4900mq. It will rev the Delta cpu fan to full speed and then down again for light loads like switching between render mode and back in Rhino, I don't know what to make of that.

That is correct, the magnet is on the rail for LVDS displays.
On eDP displays there is no rail so the magnet is suppose to be glued into place on the display bezel, the plastic rim with the DELL logo.
There is a slot where it just slides in on the left side of the bezel
Put some contact adhesive and slide it in. Make sure its oriented correctly so it will pull when the lid is closed.
I bought all my parts brand new off aliexpress so my bezel didn't come with a magnet so I ripped the old magnet off the LVDS rail with a pair of pliers and glued it in to the plastic bezel.




I hope you got all the parts because the
1. Lid
2. Bezel
3. Hinges
4. cable assy (different length)
are all tied to one configuration

The cable assy is not a flex cable but an old school wire wrapped in metal tape.
These cables are VERY thin and fragile, probably over 28 AWG, you can unwrap the wire loom to find if there is a broken wire.
But this is specialty skill, what we did in the 90's early laptops.
I have done it because I modified the wire loom to fit a 3'rd party LVDS IPS display that has the port in the middle.
It can be a fuse, it can be a cable break.
If you like to get technical:
https://www.repairlap.com/threads/d...a-9771p-rev-1-0-a00-boardview-schematic.2122/
https://bdbios.com/wp-content/uploa...on-M4800-WNW0H-La-9771P-MODEL-NAME-VAQ10-.pdf

You can also try sliding a powerful magnet over the left part of the keyboard to play with the hal sensor and see if its been stuck shut.
I've written about the hal sensor a few pages back.

The chirp noise is there on every AVC and Delta fan I have.
I am not sure if its supposed to spin freely but they do.
It is the bronze or copper sleeve spinning freely due to the starting torque making a little chirp sound when the fan start up, it will then stop so its only at startup you'll hear this sound.
I tried to find a solution to this but there is not enough space to get down there and squirt some low viscosity CA glue there with a mini pipette without getting the inner sleeve wet.
And the housing is not compatible with CA glue, seem to be some ptfe in the plastic around the stator and the other parts of housing having glass fiber.
It would explain why the sleeve is eventually breaking loose over time.
And the space above the sleeve is reserved for the convex cone on the end of the shaft at the impeller to rest so there is no tolerance to add any CA glue.
Not unless you go in from the bottom, which is pretty much not an option unless you're willing to remove the electronics from the housing which is glued in from the factory.

 

If it was a problem with the hall sensor then Windows would be going to sleep mode immediately. But it doesn't do that, so it may be the cable at fault. When I installed the new lid I didn't notice the cable was being pinched as I was screwing it in where the old lid was. I'm hoping it's just the cable at this point but finding cables is confusing.

I'm getting listings of LVDS_EDP cables, and are those eDP at all?
WJ64D in question. And it looks like this:

 

The WJ64D is eDP fullHD only, with additional wire loom for webcam.

The other options are 0GHFJ for UHD and 93YWD for QHD.

https://www.parts-people.com/index.php?action=category&id=142&subid=457&refine=lcd+cable


What is the full model number of your LCD panel?

 

I don't remember the panel I initially tested with the eDP cable that came with the lid but, the other panel was the NV156FHM-N43 that was in my Zbook 15.

And I'm only looking for eDP Full HD only, nothing higher. Is there such thing as the LVDS_EDP cable? It's hard to tell if it's either eDP or LVDS.

 

If its full HD eDP its a 2 lane 30 pin eDP connector.
If its a UHD or QHD its a 4 lane 40 pin LVDS connector in eDP signaling.

You need extra lanes for higher res so in order to do so you utilize the 40 pin LVDS connector but it is completely different pinout.


If its LVDS its a 2 lane 40 pin LVDS connector
If its rated for under full HD for example say 1600x900 its a 1 lane 40 pin LVDS connector.


For example your display lookin at specs:
https://www.panelook.com/NV156FHM-N43_BOE_15.6_LCM_parameter_26503.html

Has a 2 lane 30 pin eDP connector indicating this is the correct part https://www.parts-people.com/index.php?action=item&id=19968
Panelook is a very good website, it has most if not all displays and different models of a display you can imagine.

 

Is the cable in the pic a genuine one at all?

 

Yes Parts-People are the to-go part store for Dell parts.
Expensive yes, but you can find all the parts you need.

The part number WJ64D is part of the qr code if you zoom in on that part of the image.
You can call them and email them if you like, they answer in a few hours with texas local time.

If you shop elsewhere always email and confirm the image is the "ACTUAL" part item sold and not a stock item.
Dell parts are difficult to come by and 95% of the time it will be a stock image.
That's one negative point I have with dell parts, the price and difficult to find the part number you need as advertised in the listing.