Re: Macbook mid-2012 Keyboard issue

I hink the internal USB hub is contained within the trackpad. That may explain a lot.

Re: Apple Cinema Display 23" Troubleshooting - Another Case

OK, after some more reading up, it seems that U8 most probably is the dedicated EDID EEPROM of the ACD.
As it seems, somehow, sometimes, the EDID info on this EEPROM gets corrupted. This may happen because of brownouts, by hot-plugging, or whatever.
SCL is not the system clock, only the clock of the EDID signal. DVI EDID is imparted via Philips I2C, a bi-wire protocol using SCA and SCL pin 6&7 on the 29 pin DVI connector.
What you've accomplished by cutting SCL is probably tricking your PC/Windows...

Re: Apple Cinema display 23" ... detection problem

Nej snakke Norsk, Svenska, Dansk, but I've got the drift... Sorry. English my pleasure.
Although "Nederlands" is not to be counted amongst the "Northern Germanic" aka "Viking" (no offence intended) languages Philips I2C is included in the DVI protocol as a "2 Wire Protocol", carrying SDA (DDC Data) and SCL (DDC Clock).
Best read my post #27 here on the subject.

Re: Apple Cinema display 23" ... detection problem

Hey Porto, we're probably not talking Schmitt trigger but EEPROM here. I wonder if it's U8 you've removed. I believe U8 is an EEPROM responsible for communicating EDID info to your computer with the monitor still switched off, and PSU checked out as functional.
Once the monitor is properly switched on, I think U1 will take over EDID info over 2 wire serial com (SDA +SCL)
Hee man, ik spreek ook Nederlands!

Re: Apple Cinema Display 23" Troubleshooting - Another Case

Hi Ixusss, I think by severing U1-pin 32 you've cut off the DVI system clock from your main microprocessor. This is not what I meant by my EhMac comment!
Strange thing is, your U1 still seems to be generating EDID info.
I meant incapacitating your cherished U8 by cutting the U1-pin 28 (Primary Test Data Output) link to it. For I think the U8 EEPROM is only there to impart EDID info to your computer with the ACD display unpowered.
So, temporarily suppress U8, power the ACD, next start up your pc and...

Re: New Members - please post your introductions here

Hi everyone,
I'm a veteran contributor to various Mac fora (Flemish/Belgian, Dutch and Canadian), but I'm a bit of an electronics enthusiast too. And these Mac fora leave me starved of any intelligent comments on component repair.
Found this forum trying to understand some Apple Cinema HD Repair notes on EhMa.ca by forum member ixuss.
Being versed - and self-taught almost exclusively in analogue audio circuitry and general AV connectivity because of my hobby and job (yes, with me luckily both merge!), I daresay...