Apple Cinema Display 27" No TBolt - Buzzing and then dead

[selldoor]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Beginner - what make series of caps did you buy?
You should also replace the orange caps- at least two well respected members suggested that?

[BeginnerEnthusiast]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Hello!

Typturbo tried replacing the orange caps but it did not help so I am sceptical. I am probably going to buy a new PSU altogether and hope for the best!

I wonder what it could be though. It is a strange thing that we could not find the cause to this.

[Th3_uN1Qu3]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

If it's gotten this far then i suggest there might be a problem with the CCFL lamps themselves or the connections to the lamps. AFAIK this display uses CCFL not LED backlighting, correct me if i'm wrong.

[BeginnerEnthusiast]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

The screen is called Apple LED Cinema Display 27" so it must be LEDs right?

I picked up the new PSU today so I will pop it in there tonight and give you guys an update later.

Long time, long thread this one Thanks for sticking with it!

[selldoor]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

"I only replaced the green taicon capacitors" what did you replace them with

[BeginnerEnthusiast]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Hey!

I can't remember the manufacturer but tonight I will have some time to put the new PSU-card in there and then I will be able to look it up!

Stay tuned.

[BeginnerEnthusiast]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Hello again fine users of this forum.

I have now ended the weirdly long saga of "the buzzzing LED cinema display". I think. It has so far lasted almost a year.

I got my new PSU last week and popped it in there. So far, everything works FINE! And I am so happy I am dancing on tables everywhere I go. It is silent and it is bright and beautiful.

NOW, this doesn't mean that it is guaranteed to stay that way but I am crossing my fingers.

About your question, selldoor, the caps that I replaced the old Taicon caps with are: KSC coloured black and YAGEO coloured brown. Below I have attached two photos of the new caps and also a photo of the orange film caps that made the buzzing sound.

How come you ask about the new caps? You have a theory perhaps. I would be happy to hear it!

Thanks, Jakob

[selldoor]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Well I was hoping you were going to say Panasonic Nichicon or Rubicon or UCC with low esr and high ripple. The caps you have used are not usually recommended for this type of application.
I do not fully understand it but I believe that caps that can handle a higher ripple current
allow less AC through - it could be the AC that is causing the buzz. There are many posts regarding this.

[BeginnerEnthusiast]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Allright! Thanks for the tip.

I am hoping I won't need any more troubleshooting on this piece of machinery in the future. The new PSU is still working fine.

[nikon331]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Wish mine was bad caps turned on one day smoke from bottom speaker grills and found the power supply fried inside. Just glad it didn't burn down the house when I was gone. Bad Apple. Called apple tech support no help since a few months out of warranty.

[mbrick]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

You could email the photos that showed it nearly caught fire, or take the board into the store and show a manager, might change someone's mind.

[BubbaJ2k2]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Hey guys,

It looks like Apple kept a good thing going (not) and continued to use the same power supply in the Thunderbolt 27". I'm trying to repair mine now -- have the infamous no backlight, but I can see the digital image on the panel using a flash light.

I suspect it's this black part on the board that's faulty, but I am having trouble identifying what it is. Any ideas? I've been scouring the web for answers, and you guys seem to be the most knowledgeable, so I appreciate any assistance!

http://bubbaj2k2.imgur.com/all/

[BubbaJ2k2]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Follow Up: I was able to find this Chinese document from a part supplier for Lite-On, for what I appears to be the power supply:

http://wenku.baidu.com/view/a491f5370b4c2e3f5727638a

I looked up the part number, 37-C3271301-HF, and found this description:

PFC CHOKE A3271-3A DS4014 JPP44A

I checked Digi-Key and ebay for PFC Choke, but haven't found much. Does this make any sense to anyone?

[Behemot]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Any idea what's inside the Apple Thunderbolt Display? I have been asked to have a look onto one which has problem with lack of backlight so what can I expect?

[TheChuckster]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

My Apple Cinema Display 27" No TBolt display completely died a few days ago. For the months leading up to its demise, a buzzing sound emanated from the inside of the monitor.

Thinking this buzzing was caused by bad electrolytic caps, I just swapped out all of the Taicon electrolytic caps with Rubycon, Panasonic, and Nichion caps. The board was successfully brought back to life , and it even stopped buzzing for about an hour, but then it started buzzing again.

I'm sourcing replacement film capacitors now.

Any ideas on how to quell the buzzing if the film capacitors are not the culprit? Could it be the transformer?

It's a shame that this is an Apple product.

[Mr_nice]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

Hey guys,

It looks like Apple kept a good thing going (not) and continued to use the same power supply in the Thunderbolt 27". I'm trying to repair mine now -- have the infamous no backlight, but I can see the digital image on the panel using a flash light.

I suspect it's this black part on the board that's faulty, but I am having trouble identifying what it is. Any ideas? I've been scouring the web for answers, and you guys seem to be the most knowledgeable, so I appreciate any assistance!

http://bubbaj2k2.imgur.com/all/

Hello Bubba, and fine people of this board,

I just wanted to know if you got anywhere in your solutions for this problem. My screen is doing the same thing now - no backlight - speakers and camera work fine. had the power supply outand visible checked caps - none appear damaged. any help most welcome.

nice

[sbyseven]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

I have found this:

https://www.instructables.com/Fixing...le-27-Display/

[Behemot]

Re: Apple Cinema Display 27" No TBolt - Buzzing and then dead

interesting, never would've imagined this to be a cause of failure, thanks dude!