iMac käynnistyy sammuakseen?

[jerppuli]

Hei.Kaverin laitteen sain korjaukseen kun näyttö oli pimeä.En tiedä oliko joku liitin huonosti kun mitään varsinaista korjausta en laitteelle tehnyt.Nyt laitteen ruudulle tulee omppu ja käynnistyspyörä jonka alle tulee"käynnistyspalkki" joka noin viiden minuutin jälkeen täyttyy ja sen jälkeen kone sammuu.Kone on 27-tuumainen ja vuosimallia 2010.Kolme erillaista resettiä koneelle suoritettu.1tai4 "tilaledi" ei pala.12volttia hieman ehkä alhainen(11.8v ilman näytön kytkemistä)
Appleista ymmärtämätön kysyy että mitäköhän tuo palkki meinaa ja mistä kannattaisi seuraavaksi tehdä

[peku]

Diagnostiikkaledien merkitykset:

LED #1
• Indicates that trickle voltage from power supply has been detected by logic board. This LED will remain ON whenever the iMac is connected to a working AC power source. The LED will remain ON even when computer has been shut down or put to sleep. The LED will remain OFF only if the AC power source is missing or disconnected , if the logic board is disconnected from the power supply, or if the power supply board is faulty.
LED #2
• Indicates that the main logic board has detected proper power from the power supply when the computer is turned on and that logic board voltage regulators are functioning properly. This LED will be ON when the computer is turned on and the power supply should be working correctly.
LED #3
• Indicates that the computer and the video card are communicating. This LED will be ON when the computer is communicating properly with the video card. If LEDs 1 and 2 are ON and you heard the startup sound, but LED 3 is OFF, then the video card might be installed incorrectly or need replacement.
LED #4
•
Indicates that the computer and the LCD panel are communicating. This LED will be ON when the computer is turned on and video signal is being generated. If the LED is ON and there is no image on the display, then the LCD panel, the LED backlight board, or the cables between might be installed incorrectly or need replacement.

LED Startup Sequence
LED #1 = Power available.
If no LED is visible:
• Verify AC power source
• Verify known-good AC cable is connected
• Verify cable connection between AC inlet and power supply
• Verify cable connection between power supply and logic board
• Verify power supply
LED #1 + LED #2 = Power available, and system is powered on.
If second LED is not visible when power button is pressed:
• Verify power button connection to logic board
• Verify power button functionality
• Verify cable connection between power supply and logic board
• Verify power supply
• Verify logic board
LED #1 + LED #2 + LED #3 = Power available, system is powered on, and video card found.
If third LED is not visible after power on:
• Verify that the MXM video card is seated properly
• Verify if boot chime is present and fans are running when powered ON (reset SMC
and PRAM, check backup battery if necessary for proper boot up):
• If POST boot chime is not heard, go to Won’t Start Up symptom flow,
• • If POST boot chime is heard, go to No Video symptom flow.
LED #1 + LED #2 + LED #3 + LED #4 = Power available, system is powered on, video card found, and internal LCD found.
If fourth LED is not visible after power on:
• Verify cable connections between LCD panel and logic board
• Inspect LCD display cables for cable damage
• Verify external video functionality, and according to result check the following items:
-If external display works then verify/replace the LED backlight board -If external display works then verify/replace the LCD panel
-If external display does not work verify/replace the logic board

[kaulahuivi]

Laitevika. Huoltoon vaan. Korjaavat sitten näytönohjaimen, muistin, emolevyn tai kovalevyn.

[full]

Emo tai näyttis viallinen.

[jerppuli]

Eli joku osa tietokoneessa ilmeisesti viallinen?
Onko tuo palkki joka latautuu noin viisi minuuttia jollekin tuttu?
En ole googlettamalla löytänyt tuosta oikeastaan mitään tietoa.