Repareer je spullen Gemeenschap Winkel

Model A1311 / Late 2009 / 3.06 or 3.33 GHz Core 2 Duo processor

311 Vragen Bekijk alle

Opties

iMac won't turn on, especially with RAM sticks

iMac (late 2009) won’t turn on and here is how it works:


When I plug the cord one green LED turns on, second LED never appears

Before cleaned out RAM contacts with alcohol when I pressed power button I heard fans and hard disk sounds but no screen and no boot chime.

After I cleaned and reinstalled RAM fans run only when memory sticks weren’t installed (sometimes it run and shut down randomly) and when I have memory sticks in it fans doesn’t run, actually I hear how they try to run for a second.

What can be damaged? Power supply? Logicboard? and what it has to do with RAM? or maybe memory itself is the reason?

Beantwoord deze vraag Dit probleem heb ik ook

Is dit een goede vraag?

Ja Nee
Score 0
2 opmerkingen

So before you altered anything the system wasn't working - correct?

door

@danj yes it didn't. just fans and not even boot chime

door

Voeg een opmerking toe

2 Antwoorden

Filteren op:
Meest nuttige Nieuwste Oudste
Het nuttigste antwoord

Opties

IF your system was not working from the get go, I’m suspecting the power supply has failed given the onboard diagnostics

Here's a breakdown of the onboard diagnostic LED's

LED 1 - Indicates that the trickle voltage from the power supply is detected by the main logic board. This LED will remain ON while the iMac is connected to the AC power. The LED will remain on even when the computer has been shut down or put to sleep. The LED will turn off only if the AC power is disconnected or the power supply is faulty.

LED 2 - Indicates that the main logic board has detected proper power from the power supply when the computer is turned on. This LED will be ON when the computer is turned on and the power supply is 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 display 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 LCD display panel, the LCD display panel or inverter might be installed incorrectly or need replacement.

So clearly the lack of LED #2 tells us we need to focus on the power supply first. Its also possible the logic board has a problem as well. I often find power surges and lighting strikes kill both. Are you using a good quality surge suppressor? Or better yet a UPS? Did you check the outlet to make sure the ground is properly wired and at the breaker panel make sure the ground line from it is properly bonded to either a copper water pipe leaving the house or one or more grounding rods.


Was dit antwoord nuttig?

Ja Nee
Score 2

2 opmerkingen:

If there is no way lightning strike can be the issue that means there can be less chance of logicboard being also damaged?

door

Cross your fingers ;-} Power surges are still on the table.

door

Voeg een opmerking toe

Opties

If the system only runs when the RAM sticks are not installed, then your RAM may be the problem. Please see if replacing the RAM sticks doesn’t help. They usually don’t need to be cleaned, and be careful to not touch the metal contacts on the bottom of the sticks.

Was dit antwoord nuttig?

Ja Nee
Score 1
Voeg een opmerking toe

Voeg je antwoord toe

Ange Vrai zal eeuwig dankbaar zijn.
Weergavestatistieken:

Afgelopen 24 uren: 0

Afgelopen 7 dagen: 1

Afgelopen 30 dagen: 4

Altijd: 122