• Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.

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  1. Topic title should contain: the device's manufacturer, full model and the brief description of problem.
  2. Topic message should contain: the PCB marking code (required in case of hardware repairs), an extended description of problem, things you have checked/replaced/measured, your conclusions and the question. If you are not able to find the PCB marking code, please read THIS TOPIC. If you still cannot locate the PCB markings, please upload a clean, both-side photos of the mainboard - it is required to remove any films, modules or brackets possibly covering these markings.
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#1 Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by matrixmm 11 May 2024, 12:27
Cześć, mam na stole płytę LA-F712P.
Posiłkuję się schematem i BV od LA-F711P. Płyta po wciśnięciu power mignie na sekundę klawiaturą i gaśnie. Płyta pobiera 0,03A. Wstępnie zaobserwowałem, że po podłączeniu zasilania na cewkach PL100 i PL101 napięcie pojawia się na sekundę i gaśnie i tak w kółko. Idąc tym tropem doszedłem, że po podniesieniu zwory PJP20 napięcie się stabilizuje. Znaczy problem jest gdzieś po stronie +1.8V_3.3V_ALW_VTR3. Po podniesieniu zwory PJP20 rezystancja na n.2 PJP20 wynosi 6,5M.
Pomierzyłem napięcie na obu nogach podniesionej PJP20 :
PJP20
n.1 - 1,8V
n.2 -1,4V
Czy napięcie na n.2 nie powinno być 0V?
Czy to wskazuje na uszkodzony KBC (U1)?
Jak zawsze będę wdzięczny za wszelką pomoc.

Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by Google Adsense [BOT] 11 May 2024, 12:27

#2 Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by matic 13 May 2024, 07:55
Hello!

Measure the voltage to ground on coil PL501. Is this voltage stable even with the jumper PJP20 closed?

#3 Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by matrixmm 13 May 2024, 15:29
matic wrote:Measure the voltage to ground on coil PL501. Is this voltage stable even with the jumper PJP20 closed?

No, after shorting PJ20, the voltage on PL501 pulsates cyclically 1.8V-0V approximately every second.

#4 Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by matic 20 May 2024, 08:31
Measure the voltage to ground on pins 1 of chip PU501 with the jumper PJ20 closed. Does this voltage also pulsates cyclically?

#5 Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by matrixmm 21 May 2024, 09:28
matic wrote:Measure the voltage to ground on pins 1 of chip PU501 with the jumper PJ20 closed. Does this voltage also pulsates cyclically?

The same, after shorting PJ20, the voltage on p.1 PU501 pulsates cyclically 3V-0V approximately every second.

#6 Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.  [SOLVED]


by matic 22 May 2024, 10:02
Try to reflash the BIOS chip.
If it doesn't change anything, replace the PCH chip.

#7 Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by matrixmm 26 May 2024, 21:07
I looked carefully at the motherboard again.
I noticed a small trace of flooding near PU901 (charger). I washed it thoroughly and replaced the charger. The motherboard came to life. Everything works. Thank you very much for help.

Re: Dell Precision 3530 płyta LA-F712P uruchamia się na ułamek sekundy.


by Google Adsense [BOT] 26 May 2024, 21:07

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