Re: Post your Samsung NU model series backlight failures and diffuser melt-downs here
First of all i feel i must state it's a shame of Samsung to design and sell this kind of crap, in my case a UE43NU7122k tv, but what can you do...
So I'd like to share a good solution i thought of and tested successfully (perhaps it's meant more for the casual enthusiast rather than the professionals, as it requires small modding).
So to the point.
The diffuser is definitely directional. It allows more light to go through at the top and less at the bottom,...
Asxetos21
Member
Last Activity: 04-06-2024, 09:25 AM
Joined: 12-09-2019
Location: Iraklion, Creta
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Last edited by Asxetos21; 03-17-2022, 12:02 PM. -
Re: Dell Precision 3520 Troubleshoot
OK, after a lot of searching i located the VGA_ID resistor, of-course it was configured for discrete graphics.
I moved it to the UMA graphics configuration.
Now a question before i power on.
IF after all it's a graphics problem should i see POST regardless of ME corruption? Or should i take care of ME corruption first?
(i had no idea of what a pain ME firmware was!!!)Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
My bad sorry, i didn't clarify.
Both of my laptops are H cpu. i7-7820HQ on the Precision, i5-6440HQ on the 5580. i checked, same ME firmware...
5580 is sold with both U and H options, but mine has the H cpu.Last edited by Asxetos21; 12-12-2019, 10:04 AM.Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
I tried them both, i am on the smdflea's second one now.
One question. I also own a Latitude 5580 with similar hardware (i7 and nvidia for the 3520, i5 and nvidia for the 5580).
They are practically the SAME laptop, with various cpu and gfx options.
They even share the same bios update file (same update .exe from dell). The bios has all necessary modules and drivers to cover all options.
Is it OK to flash the 3520 with a dump taken from the 5580?Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
I already removed the 2 gfx_core supply coils and powered on. 1 out of 3-4 attempts the board posted (but only 1 out of 3-4).
About the VGA_ID resistor change, now that is a tough one...
Small discrete components (single resistors and ceramic caps) are NOT numbered on this board. To make things worse, UE1 is a BGA chip, so tracing VGA_ID pin and resistors would be next to impossible. I will look into it...
Thanks mcplslg123....Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
That's an interesting idea, but I am afraid i will need some more clarification on what to do.
You mean Nvidia graphics might be the default during POST and might be that the board does not rise UMA graphics voltage on boot by design?
PS. According to the schematic, removing PL1301 and PL1302 on my board should do the job...
Thanks for the UMA schematic, i already have it...
As i wrote 2 posts above i already compared the circuitry around PU612,PU613 and PU610,PU611 (voltages,...Last edited by Asxetos21; 12-12-2019, 12:15 AM.Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
I mean PU612 and PU613 which control the missing VCC_GT. PU614 is for VCC_SA which rises fine.
It will take some time to trace the signal on the board and measure it, but to me, it must be working.
Per the schematic, PU601 controls ALL CPU voltages (VCC_CORE, VCC_GT and VCC_SA).
If IMVP_VR_ON was missing, none of the 3 voltages would rise. But as measured, VCC_CORE and VCC_SA rise just fine...
Searching, I measured PWM1_VCORE and PWM2_VCORE on PU610-PU611,
and compared it...Last edited by Asxetos21; 12-11-2019, 01:02 PM.Leave a comment:
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Re: Dell Precision 3520 Bios
I will ask the community again,
Can someone provide a full working dump (programmer readout, and unmodified) from ALL 3 flash chips on a Dell Precision 3520 with an i7-7820HQ cpu?
It has been proven (also by me) that ANY modification on late (>2016-2017) generation Dell laptop bios can lead to similar behavior. It does not pass the built in digital signature tampering verification, so only a good readout from the same hardware will work.
On a 2017 dell Latitude (same generation) i requested a NVME module replacement...Last edited by Asxetos21; 12-11-2019, 10:12 AM.Leave a comment:
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Re: Dell Precision 3520 Bios
No luck, same thing.
On 1st DC connection, the power light goes on for 3-4 secs and then it stays off, the battery led blinks white forever.
I left it settle for 15 mins before i tried to power it on manually (long power button press). It powers on for like 10 secs then stays off (and behavior is repeated).
PS (correct me if i am wrong)
To my knowledge, ME firmware is a combination of a piece of BIOS code, and a piece of firmware that is flashed directly inside the CPU when the ME version is changed...Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
off= 0v
on= 1.2v...Leave a comment:
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Re: Dell Precision 3520 Bios
Thanks SMDFlea,
Didn't work, same behavior.
Can someone provide a full working dump from ALL 3 flash chips on a Dell Precision 3520 with an i7-7820HQ cpu?
Don't care if it's password protected, i just want to see if it brings the board to life.
UC5 is the main bios (under the fan)
UT2 and UT6 are for Thunderbolt firmware and EC settings (next to the USB-C plug).Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
The voltages on the switches are OK. VDD 5.0V VIN 13,50V. But as always no power on the VCC-GT rail.
PS. The bin you gave me doesn't work. Same behavior...
Thanks...Leave a comment:
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Dell Precision 3520 Bios
Thanks mcplslg123 your advice is solid.
I could not agree more on the "don't mess with hardware unless necessary".
I attach the original bios dump the board was on when it started dying.
If someone could have a look for any bios corruption?
[ATTACH]203949[/ATTACH]
Thanks...Thanks mcplslg123 your advice is solid.
I could not agree more on the "don't mess with hardware unless necessary".
I attach the original bios dump the board was on when it started dying.
If someone could... -
Re: Dell Precision 3520 Troubleshoot
By "gfx core" i thought you meant the bios part. I am just saying how can one "more" bios flash fix what looks like a hardware fault.
My feeling is it could more likely be a bad switching controller, a shorted or open switching fet, an open solder joint on the cpu, etc etc...Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
The ram is tested good. Working fine on a second laptop (same generation), just checked again.
Gfx core missing? I don't think so. 3 different direct flash dumps for the same laptop reflashed should show some difference....Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
Ok, Here are some pictures and measurements...
[ATTACH]203942[/ATTACH]
[ATTACH]203943[/ATTACH]
COIL FUNCTION OFF ON
PL901 DC-IN 19,50 19,15
PL902 BATTERY - DC-IN SWITCH 3,06 13,50
PL201 DDR 1,2V SUPPLY 0,00 1,20
PL100 3,3V POWER RAIL 3,36 3,37
PL301 1V-SUPPLY 1,00 1,00
PL612 CPU GT ??? SUPPLY 0,00 0,00
PL613 CPU GT ??? SUPPLY 0,00 0,00
PL610 CPU...Last edited by Asxetos21; 12-09-2019, 05:10 PM.Leave a comment:
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Re: Dell Precision 3520 Troubleshoot
Thanks techtiger, I'll do that and get back.
In the end i don't think its a case of bad bios. When it started, i was on the same bios for quite some time.
But like you, my first thoughts were 1. bios (hence the bios flashing) 2. SOC solder joints 3. something else...
Thanks piernov, but i won't even go that way. The laptop is a "salvage". A dirt cheap liquid damaged one off Ebay, with a bargain motherboard again off Ebay. Not even the service tag's on the casing and the board...Leave a comment:
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Dell Precision 3520 Troubleshoot
I could use some help to troubleshoot an "almost dead" Dell Precision 3520 laptop (CDP80 LA-E152P board, Intel i7-7820hq cpu, Nvidia quadro m620 gpu) that started to die on me a few weeks ago.
Usually it will not POST, power button led stays on only for a few seconds with no other life signs. When the charger is connected it does the same, but the front battery indicator led slowly flashes white for ever (with or without any actual battery connected).
On very rare occasions it has POSTed, on one occasion i was even able to update the bios to the latest....Last edited by SMDFlea; 07-05-2023, 09:49 AM. -
Re: New Members - please post your introductions here
Greetings, i ended here looking for some help...Leave a comment:
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