[SOLVED]820-3588-a iMac boot but no image on screen

[dukefawks]

I don't have the BV don't think it is available. You don't need it for something this simple.

 

[fbarcella]

Should I test with the display connected ?
I find hard to identify the components without BV.
I don't find 12 volt on 1-6 pin of J4400 but 3V and meanwhile a measure it go down

 

[dukefawks]

It is connected directly to 12V bus, look at diagram. Either dead L4400 or F4400

 

[fbarcella]

If it's the fuse F4400 should I investigate why it's blowed before replace it, right?

 

[dukefawks]

Probably because of a fucked up cable that was plugged in or a short in the connector.

 

[fbarcella]

No Title

If I have identified right the components I assume that could be the fuse, right?
The 3V measured could be a tension returning from other place?
Thanks

 

[dukefawks]

Yes the fuse is dead.

 

[fbarcella]

Ok, semi solved, After changed the fuse the screen wasn't light up at all, so changed the LCD cable seemed to works. (So the cable made a short I presume)
Now the Mac is very slow and in ASD remain one error on Sensor Temperature TL0p - LCD Proximity (test 1) .

have I a problem on LCD circuit or on Motherboard?

Thanks

 

[dukefawks]

Is the sensor on the LCD panel present, is a separate sensor connector is next to LCD connector on the LCD panel.

 

[fbarcella]

I will ban myself from this forum!! There was the cable misconnected!!

 

[fbarcella]

No Title

I've tried to install on it a WD Scorpio and the Pin11 is already grounded on that disk, but the fan is still flowing at maximum speed.
I'm pretty sure, but I want to try, that there wasn't fan speed problem with Samsung EVO SSDs, don't know why

 

[jgraffis]

No Title

switch to this type of sensor.

 

[dukefawks]

I doubt pin 11 is grounded, did you count from the correct side? Pretty much all HDDs made after 2006 have the pin connected to the HDD MCU. If you ground the pin the HDD temp will read something like 7C, so within the expected value.

 

[fbarcella]

No Title

Ok, was the wrong pin!
Anyway I think that I cannot short to ground that pin, it's used. Right?

[UPDATE]
I've made it and all is wonderful working.
I consider this thread SOLVED
Thank you