Hi guys hope u all doing fine . I was hoping you can help me out to repair my bios with maybe a clean me region .The Imac chimes but i get no post or picture.
imac A1418
Serial D25K70EXDNCT EMC: 2544
Model: Imac 21.5 '' A1418 MD094LL/A
Board Model: 820-3302 EMMC: A1418...

Apple iMac A1418 21.5" Logic Board 820-3172 820-3172-A Schematic...

Hello friends,

I have this unit with no backlight on screen. After inspection i determined there is a shorted capacitor on BKL_BOOST circuit. I removed the capacitor, short is gone but backlight still not working. I found that Q9702 is not open and R9721 is only around 70kOhms but according to schematics it should be 301k. I removed the resistor and connected the gate of Q9702 directly to GND. Now i have 12v passing by the mosfet to turn on backlight IC LP8561 (U9700) but BKL_BOOST circuit is not working. I can measure only 12V there but it should be around 60V.

Can you...

hello friends, this time i've got an imac wich needs to be uprgaded to the highest ammount of ram possible, in other cases i've had 27" iMacs that can go as high as 64GB of RAM, no issue. however, this particular case is getting kinda tough...

Case is that i install one Stick of 16GB @1600mhz paired with another 8GB @1600mhz and it works flwalessly.

Problem comes when i install the 2X16GB STICKS @1600mhz

gives the chime immediatly.

I remember once a senior member here piernov Posted a case where a particular ram would not fit some particular...

Apple iMac A1418 820-3302-A Boardview...