does pin 4 connect to to pin 26 UI4 ?
could you complete the following list so all pins are checked (don't have a schematic myself)
UH6
pin 1,13,14 to pin 17 UI4 BBU
pin 2 to pin 9 UL1
pin 3 to pin 15 UF3
pin 4 to pin 26 UI4
pin 5 to pin 3 UL1
pin 6 to
pin 7 to pin 4 UL1
pin 9 to pin...
Hello Macalle,
you have to check the connections from the pins of UH6 all the way to the CAS PAL UL1
and also to VLSI UI4
The must be a broken connection there
In my case the connection was broken from UH6 to the via, but in your case may be somewhere else on the line.
Will replace the opto, have a number of them in stock.
disconnecting the HDD is same result
Does not explain that the board wih another analog board has the same problem. And another mainboard with both anolog boards is working ok..
Pressing the reset switch does not help.
Tested the board yesterday again. tuned the voltage back to 12V and 5V (as close as I could get) installed a PRAM battery (empty don't have a charged one)
Measured the voltages, go up to the 12v / 5v in seconds and stay stable (cool boot).
Was...
checked the voltages at the hd power connector, 4.96V and 11.97V
Boosted the voltages a bit to 5.08V and 12.20V
problem seems to stay about the same.
For the reset line, how do I check this?
am trying to repair a Classic II
- replaced the capacitors on the mainboard and the analog board
- removed U14 , cleaned underneath and replaced
- removed egret , cleaned underneath and replaced
- reflowed some connections
problem is when I turn on the Classic II, the attached screen...
Hi,
I have a problem with a SE fdhd, the system is working ok, except for the screen. The top left corner seems to be lower than the right one. The overal picture is reasonably straight.
In the second picture i have drawn a box around the screen so you can see the problem better.
Can anyone...
Can confirm this, have a AB with no voltage on the secondary side, primary side seems ok, every component checks out, Replaced the capacitors on the secondary side did not fix it.
When I replaced the TDA4605 the board started working!!
This is the component I replaced:
This is another one...
RP2 is a surgistor, protects your mac by eliminating the destructive turn-on currents.
You can measure it on the board has to be around 20 ohms
The resistors in your picture are:
RP1 22K 3W
RP44 22K 0.25W
RP13 100K
RP14 220K
RP18 220K
RP19 220K
RP46 470K
looks like RP13 in your picture...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.