iM 4,1-14,4 Late 2009 27” no boot and no LEDs on logic board

[netrix]

Hi, I have been doing some reading on here but have come to a stop on what to do next, so after any advice please ….
The IMac had very little use recently and now when trying to power up there is nothing, no clicks, fans, buzzing or anything on the screen.
I took the front off and the LCD screen out, plugged in the power lead but no LEDs (I assume I’d be able to see them with room lights off ?)
on the 14 pins on the logic board I have 12vdc between pin 1 and 4 and between 1 and 11, but as mentioned no LEDs
I think that there being no LEDs rules out a physical issue with the on/off switch and wiring ?

What would be my next steps - replace logic board or power board ? I don’t think I have the skill/knowledge to diagnose any deeper, so will probably have to result to swapping stuff out.

Thanks in advance for any suggestions

Netrix

 

[netrix]

I suppose my main question is if there are no LEDs lit on the logic board when the 240v power lead is plugged in and switched on (expecting to see 1 LED lit) but I do see 12v between pins 1 and 4 on the logic board, would that indicate an issue with the power board or logic board ?
I have had the logic board out to check the coin battery and all good at 2.8 volts
(Getting that board back in is another story !)

 

[Nguyen Duc Hieu]

No LED of weak LED (in my case) is the signal that the PSU doesn't connect well with the logicboard. (PSU is bad of both are bad).
In my case (weak LED on iMac 2011), the PSU and the logicboard are both bad.

And for iMac 2009, it's not worthied to repair.
I would test the LCD panel.
If it was still good, I'd buy an LCD driver kit (25$) and convert the iMac to a monitor.

 

[netrix]

No LED of weak LED (in my case) is the signal that the PSU doesn't connect well with the logicboard. (PSU is bad of both are bad).
In my case (weak LED on iMac 2011), the PSU and the logicboard are both bad.

And for iMac 2009, it's not worthied to repair.
I would test the LCD panel.
If it was still good, I'd buy an LCD driver kit (25$) and convert the iMac to a monitor.

Thank you so much for the reply - I had access to a 2009 working 21” iMac and have since swapped over the hard drives and backed up all that I needed. Whilst doing this I realised how out of date the 2009 OS was, hardly any access to websites due to version of web browser and unable to update those browsers and, due to 2 factor authentication, I am unable to log into my iCloud account.

I never realised I could used the LCD as a separate monitor, using the kit you mentioned would I be able to hook the iMac screen up to a Mac mini ??

 

[Nguyen Duc Hieu]

Thank you so much for the reply - I had access to a 2009 working 21” iMac and have since swapped over the hard drives and backed up all that I needed. Whilst doing this I realised how out of date the 2009 OS was, hardly any access to websites due to version of web browser and unable to update those browsers and, due to 2 factor authentication, I am unable to log into my iCloud account.

I never realised I could used the LCD as a separate monitor, using the kit you mentioned would I be able to hook the iMac screen up to a Mac mini ??

Other people have even re-purposed their laptop LCD to a stand-alone display.
iMac LCD panel is much easier to convert. Just check the model number of your LCD Panel and place order correctly.

Dp_hdmi To Edp Drive Board Lm270wq1-sdc2/lm270wq1-sda2/lm270wq1-sde3 Control Board Kit For 2560x1440 Lcd Led Screen - Circuits - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com