As this look to me coupling capacitors, I powered on the board. Here is what I have tried till now.

1. ⁠There is only 5V and 3.3V rail present. So looks like PD controller is not negotiating 20V. I didn’t find 20V anywhere. Nor near battery connector.
2. ⁠Board does not seem to be short. 2R7 inductor near battery connector is giving 385 Ohms.

What else I can try?

Hi All,

I just got a Macbook Pro M2 Pro from marketplace for a repair project. There was no power, neither on Magsafe nor on all USB C. So there was PD negotiation as Magsafe led was not coming on at all. Its all dead. After opening the Macbook, I found liquid damage and I know exactly where there was a liquid damage.

I have cleaned the motherboard properly with Isopropyl but looks like 2 of the SMD caps/res were blown so they came off while cleaning. I could see brown burn mark on the bottom plate as well.

Can someone please let me know what are these...

Made some changes. Can you guys please review now and provide me the feedback. Any other suggestions here?...

Here is the updated one.


​
Can you please explain a bit more may be through change in schematic? Sorry new to circuits but ready to learn....

Ignore this change. I think I made a mistake by adding lower input voltage buck converter? So TPS562201 is fine or there is better option?

Thanks...

I have updated TPS562201 with TPS62840DLCR as per search online. Better option?

Adding updated schematic

...

I'm designing an ESP-based WLED controller board for WS2815 12V LED strips, with a primary focus on energy efficiency.

To minimize power consumption, my goal is to completely shut down the system when the LED strip is turned off.
However, the current buck converter powering the ESP module draws about 8 watts even when the LEDs are idle, making it unsuitable for low-power operation.

I am using below components:

• Buck Converter: TPS562201 (12V → 5V regulated)
• Microcontroller: XIAO ESP32-C3 (with built-in USB-C)
• LED Strip: WS2815 (12V digital LED strip)
• Switching

...

Great, thanks. One more thing, just got to know he did try to start it by plugging in power and nothing happened, no power? Anything bad could have happened here? No power, because resister R2206 for BIOS is missing?

Also guide me to find the trace for the pad that is missing, that is C5503, right?

Also, how can I remove that short on C5506 and C5507, I tried my best but still not able to. I have ordered hot air solder station, may be that would help here?

I have a spare board, can I replace capacitors at-least from that board? How about resistor? Can I take...

Sorry my bad. I forgot to mention the Laptop model. Its a Lenovo ThinkPad T14 Gen 3 Type 21BS. Can someone please help me out in finding the components from schematics.

Hi All,

So my friend was visiting and he wanted to use my solder bench to solder on some WLED circuit board. My laptop was open on the side for RAM upgrade. I know my mistake.

So while soldering he had too much solder on the soldering iron tip and he just shook off the soldering iron on the table itself to remove extra solder on the soldering tip and it landed on the motherboard of laptop. He then out of fear tried to remove it using solder wick and did more damage by removing some components as well. So here I am with weird situation.

I have not tried putting...

What began as a curiosity—opening up electronics just to see what's inside—has grown into my profession. I'm passionate about exploring the world of electronics, always eager to learn something new and connect with like-minded enthusiasts to share knowledge and solve problems together.​

I removed this one on the board. C178. I think it is 100uF/16V. So I don't have SMD capacitor. Will a normal Electrolytic Capacitor work here if I am able to find a one? I think this is in fan circuit. Please confirm....

SMDFlea and dellxps15 So I was able to find the short. Thank you so much for your help. So it was a capacitor. I removed it and now short is gone. But I don’t have replacement capacitor.

Can I use the PC without that capacitor or I need to replace it. Can you please let me know its value if it is needed and I will try to find it on some donor board.

Attaching the picture of faulty capacitor highlighted in green circle....

Sorry for the delay in checking, was out of town. So I injected power but I don't see anything getting hot. Any other way of finding the short?

Unfortunately I don't have thermal camera, but I can get a lab PSU and use 91% IPA, will that work?

So in continuity check mode, it is beeping. So this resistor is grounded. 00.4 value coming when checking resistance mode set at 200.

Hi All, I have a 9th Gen Dell Optiplex micro PC motherboard which doesn't power on. When I connect the motherboard with power adapter, it goes into safe mode and turns off. So from info I have gathered online, it looks like there is a short circuit on the motherboard. So can you guys help me with figuring out the issue?

I am new to electronics repair, so my queries could be naive but I am ready to learn.

So I have a multimeter and a solder with me. But I can try to get a variable voltage power supply with a thermal camera as well. From what I seen online, best way is...