iM 4,1-14,4 2011 27 iMac ambient sensor hardware support needed

[ShinyDad]

Hi,
Disassembling my iMac ends with a 100% speed of all fans. HWMonitor shows 128C for the ambient temperature. The reason is a missing smd component on the logic board. Using my spudger to disassemble the ambient temp sensor cable caused a broken line s. picture.

Does somebody know what kind of smd I need to repair the broken line?
Thanks a lot

 

[PinkyMacGodess]

How did you pull a chip off the board? Wow...

Go big, if you can (If it's a capacitor), although 'L' usually denotes an inductor/coil/ferrite bead. Hmm... You may be screwed.

 

[The_Croupier]

Just bridge it with a wire or blob of solder and it will work fine.

 

[ShinyDad]

How did you pull a chip off the board? Wow...

Go big, if you can (If it's a capacitor), although 'L' usually denotes an inductor/coil/ferrite bead. Hmm... You may be screwed.

unfortunately it is too small for any kind of letters or so.

 

[ShinyDad]

Just bridge it with a wire or blob of solder and it will work fine.

That was my first idea. Reading a thread where someone had issues with this solution let me hesitate.

 

[PinkyMacGodess]

That was my first idea. Reading a thread where someone had issues with this solution let me hesitate.

Yeah, bridging it with wire is only a great option if it was already a wire. If you have the old chip fleck, and know someone with a surface mount heater (or go 'caveman' and use a hot plate). A heat gun can be used too, but be careful, because if there are any chips on the backside, you risk making a bad situation so very much incredibly worse if too much heat is applied. Possibly with a fine point soldering iron, you might be able to gently reheat the solder with the fleck in place. Don't lift that tab though. It's a challenge. I've done a few SMD repairs, and sometimes they work, and...

At least it doesn't look polarized which is fantastic.

Without the fleck, you could be shooting in the dark, but it could be a commodity part too. No, wire? NO!

 

[Nguyen Duc Hieu]

This is not a thing you can do with a fry pan or oven.
It's not a thing you can do with a common solder iron, either.

You will need a fine tip solder iron, and a microscope.

I'm happy to leave in Ho Chi Minh City, where I can get this job done in any mobile phone repair shop for 2$.

 

[The_Croupier]

 

[ShinyDad]

View attachment 2018341

I love community. 😍 You are the best. 👏👍. My eyes are not good enough to recognize all details. Size code seems to be 402. Is it right?

 

[The_Croupier]

Sorry yeah blurry screen grab, "FERR-220-OHM" size 0402 really cheap on AliExpress.

 

[luckasa]

I had the same problem.
I've tried to resolder the 0402 resistance, but it's soooo small, and I fired the resistor (it is black now)
I've finally bridge the L5500 connector (with a simple drop and the camera macro zoom), cut the black wire of the ambient sensor, and insert a 220 Ohm resistor in the middle (solded and protected with a heat shrinkable tube).
The ambient sensor works again!

 

[PinkyMacGodess]

I did some SMD soldering for an 'advanced solder yourself kit', and the key to making it work is not much heat. That's true for all soldering, but extra important for those small suckers. Lift a pad and you are so screwed. Toast a component and you will be stuck looking for a replacement. Finding actual product and not getting taken by counterfeit junk is, or should be, a real concern. But trying to buy just one resister of that size might be difficult. Many distributors likely have minimums and that means added expense, or having to buy 'minimums' and be stuck with quite a number of them. It shouldn't be that hard and maybe Right To Repair can help address that at some point.

 

[aldergood]

This is not a thing you can do with a fry pan or oven.
It's not a thing you can do with a common solder iron, either.

You will need a fine tip solder iron, and a microscope.

I'm happy to leave in Ho Chi Minh City, where I can get this job done in any mobile phone repair shop for 2$.

Hi Hieu,

Bạn có biết tiệm dt nào nhận dán tụ này ko? Mình đi mấy tiệm mà chưa thấy tiệm nào nhận dán cả. Mình cũng bị rơi mất 1 con tụ SMD như vậy.

 

[Nguyen Duc Hieu]

Hi Hieu,

Bạn có biết tiệm dt nào nhận dán tụ này ko? Mình đi mấy tiệm mà chưa thấy tiệm nào nhận dán cả. Mình cũng bị rơi mất 1 con tụ SMD như vậy.

Họ không nhận vì họ không có linh kiện hoặc không muốn mất thời gian tìm linh kiện. Bạn phải mang cả máy và linh kiện ra thì tiệm nào cũng hàn được.
L5500 không phải là tụ. Nó là cuộn cảm.
Có thể thay thế bằng điện trở 220hm, hoặc 0ohm. Xem hình sơ đồ rút gọn ở post #8.

They don't take your order because they don't have the parts, or don't want to take time finding the part for you.
You will have to bring both the part and the iMac to the shop.
LM5500 is not a condenser. It's more like a coil.
You can replace it with a 220Ohm resistor or 0 ohm resistor, like the previous described "bridging"
Check the layout chart on post #8.