• Dell studio 1558 Biały ekran na VGA jest ok

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#1 Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 9 September 2019, 13:27
Dell studio 1558

Płyta DA0FM9MB8D1 REV: D
PCH: BD82HM55
GPU 216-028018

Witam kolegów.
Na matrycy jest Biały obraz na zewnętrznym VGA jest obraz poprawny.
Matrycę podmieniałem, taśmę też.
Diagnostycznie podgrzewałem PCH i GPU i dalej to samo.
Na których pinach powinny być napięcia złącza matrycy

Re: Dell studio 1558 Biały ekran na VGA jest ok


by Google Adsense [BOT] 9 September 2019, 13:27

#2 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 9 September 2019, 13:35
Hello!

Measure the voltages to ground on pins 11, 15, 17 of LVDS connector J1, when the laptop is turned on.

#3 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 9 September 2019, 14:37
Dziękuję za zainteresowanie
11-18,5V
15-2,1V
17- 3,3V

#5 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 9 September 2019, 15:13
1-0v
2-2,2v
3-3,3v
4-0v
6-0v
19-3,3v
21-3,3v

#7 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 9 September 2019, 16:48
psikus123 wrote:15-2,1V
Correct value: 3,3V
Measure the voltages to ground on pins 1, 3, 4 of Q54 and on all pins of Q1, when the laptop is turned on.

#8 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 9 September 2019, 18:02
Dziękuję matic
Programowanie BIOS nie pomogło

Q54
1-3,3V
3-3,3V
4-2,1V

Image

#9 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 9 September 2019, 19:14
psikus123 wrote:Q54
1-3,3V
3-3,3V
4-2,1V
Did you measure these voltages with connected LCD screen to the motherboard?

Measure the voltages to ground on all pins of diode D1, when the laptop is turned on (LCD screen should be connected to the motherboard).

#11 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 10 September 2019, 08:12
Wszystkie pomiary dotychczas wykonywałem z podłączoną matrycą
Pin 15 J1 - 1,26kOhm również z matrycą, pomiar D1 na foto
Image

#12 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 10 September 2019, 08:37
The enable signale "ENVDD" from the GPU is in high state, while it should be low.
Did you reflashed both BIOS chips (MAIN + EC) U40 + U39?
If so, the GPU chip is probably bad. Replace it.

#14 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 11 September 2019, 09:43
Yes, @Machine has right, my fault :oops:
Do not replace the GPU for now, because it seems that the issue is elsewhere.

Measure the voltages to ground on all pins of transistors PQ43 and PQ44, when the laptop is turned on.

#15 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 11 September 2019, 10:32
Image
Dziękuję Wam
Tak jak na zdjęciu matryca podłączona

#16 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 11 September 2019, 10:55
Voltages on PQ43, PQ44 are correct.
Measure the voltages to ground on all pins of transistors Q55 and Q56.

#17 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 11 September 2019, 11:35
Image
Pomiary jak na zdjęciu

#18 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 11 September 2019, 11:56
With this values it is most likely bad transistor Q54 (short between pins 1 and 3) or it is bad resistor R369 (330kΩ).
If both components seems ok, measure the voltage to ground on both pins of resistor R369.

#19 Re: Dell studio 1558 Biały ekran na VGA jest ok


by psikus123 11 September 2019, 12:10
matic wrote:Q54

Dobrze napisałeś?

#20 Re: Dell studio 1558 Biały ekran na VGA jest ok


by matic 11 September 2019, 12:15
psikus123 wrote:
matic wrote:Q54

Dobrze napisałeś?
Yes, exactly 6-pin transistor Q54.

Re: Dell studio 1558 Biały ekran na VGA jest ok


by Google Adsense [BOT] 11 September 2019, 12:15

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