Apple Cinema HD Display A1098 Power Adapter Repair

[edpalmer42]

I'm fixing a dead A1098 power brick and have run into an odd problem with some material that may or may not be heatsink compound.  Is anyone familiar with this material?

I've got a dead power adapter that appears to have a trivial fault.  The fuse is blown.  But when I replace the fuse, everything is fine.  Fuses do get tired sometimes.  Now, I'm putting all the heatsinks back together so I can do a full load test.  But there's dark grey silicone to glue things together, and there's some white material that has a consistency half-way between silicone and hardened heat-sink compound.  It's usually used in a 'glue' application, but there are two or three places where it might be acting as heat-sink compound.  The use of two different types has me confused.  Is it just another glue or does it also act as heat-sink compound?

I've attached a picture showing what I'm talking about.  You can clearly see both the white and grey material.  A heatsink mounts over the board and part of the heatsink is glued to the yellow transformer with the white material.  There's also another heatsink that goes over the first one.  The white material was used between them.

Is anyone familiar with this stuff?  Is it just glue or is it also heatsink compound? 

Ed

[theatrus]

There are a variety of thermal adhesives. Some are two-part epoxy mixes, others are acrylic adhesives. Its not Loctite 384 but likely something similar:

http://na.henkel-adhesives.com/product-search-1554.htm?nodeid=8797930717185

[johnjohnchu]

Hi, I am also trying to repair A1098.  Just wondering where the fuse is and what did you use as the adhesive in the end.

Thanks.

Jonathan

[kripton2035]

the fuse is the small red circle at the middle left of the picture, just at the end of the board.


my question is : how did you open this device without destroying the case ?

[johnjohnchu]

Hi, I have not tried to open it yet.  Just trying to gather as much info as possible first.  I think there is no good way to open it. Plan to use a Dremel to carefully cut around the seam until it was thin enough to crack apart.

[kripton2035]

some people replaced the A1098 with a simple power supply 24V 6A - may be it's easier ?
http://computer.dallcrown.com/repair/apple-cinema-display-lcd-monitor-replace-power-adapter/

[Mourning Star]

I know this is an ancient topic, but I have an A1098 that I'm trying to repair, also. But I do not see a fuse... this is in fact  the only visible difference between my power supply and the one in the OP's picture.


I've attached a picture of mine, in case anyone sees this old, dead thread and has some advice.



***Update***
Actually, once I put on my PCB inspection goggles. I located F1

Now to test it.

[amyk]

The fuse is the upright component that says T4A 250V next to it.

[Mourning Star]

Yes, I found it. Did a continuity test. It's good.

but it's 3 in the morning and my wife just woke up alone and wants me to come to bed.

Looks like I'll be waiting until morning to probe the rest and see where the problem lies