Faulty power bank, how can i trace the faulty component?

Thread Starter

Intrepid-code

Joined Oct 31, 2020
8
Good day everyone. So my power bank recently hit a road stop, this happened after i charged it with a supposedly faulty charger and as I am clueless with circuits, I thought one of you guys could help me fix it. It doesnt charge any device anymore, the LEDs remain on all the time with this wierd flickering. Also, when the LEDs are on (power bank powered on), the PCB emits a subtle rapid clicking sound from it. I was hoping if anyone could point me to the right component(s) that need replacement. Any help would be greatly appreciated.
It uses an IP5209 power bank SOC, a 3.7v 606090 battery as shown in the uploaded image. Am not a native English speaker so sorry about my english, thank you.1031201008.jpg
P.S it still charges fine.
 
Last edited:

jpanhalt

Joined Jan 18, 2008
11,088
Welcome to AAC.

Here is the schematic for the SOC:
1604137172539.png

When you say a "faulty charger" are you referring to a faulty supply at Vin? What was the fault (e.g., overvoltage, wrong polarity )?

As for the clicking, one may hear that with transformers, relays, and other magnetics that are being pulsed. The only such device is L1. It seems unlikely that is the source, but can you localis the noise better, e.g., with a stethoscope or cone?
 

Thread Starter

Intrepid-code

Joined Oct 31, 2020
8
Welcome to AAC.
Thank you sir for the welcome and reply.
Here is the schematic for the SOC:
View attachment 221081

When you say a "faulty charger" are you referring to a faulty supply at Vin? What was the fault (e.g., overvoltage, wrong polarity )?
[/QUOTE]
Yes at Vin, i believe the fault should be wrong polarity, maybe.

As for the clicking, one may hear that with transformers, relays, and other magnetics that are being pulsed. The only such device is L1. It seems unlikely that is the source, but can you localis the noise better, e.g., with a stethoscope or cone?
[/QUOTE]
I believe the L1 device (inductor) is resposnsible for that sound- reason is LED light of D3 and D4 only flickers in sync with the sound.
 
Last edited:

jpanhalt

Joined Jan 18, 2008
11,088
If it was exposed to wrong polarity, it may be fried. You could try replacing the controller chip. Sometimes they act like fuses and protect the rest of the IC's on the board. Of course, there are 3 other IC's that may also be affected. If you can read the part numbers on them, it might help determine the likelihood they were also affected. Replacing all 4 IC's blindly is not worth the effort IMHO.

Do you have any experience with fine pitch IC's? The risk during removal is damage to the existing PCB -- like lifting a pad. That is hard to repair.

Resoldering is easier. A hot air tool makes both steps easier.
 

KJ6EAD

Joined Apr 30, 2011
1,573
With the caveat that all Pb-free (RoHS) {Reduction of Human Satisfaction} solder joints look bad, the input end (top as shown) of R1 looks like it could be cold, cracked and arcing. This would explain the observed sound and may be visually verified by observing with a magnifier in the dark under load. A second verification would involve pushing down on the joint lightly with a small insulated probe (poking with a stick such as a toothpick) to temporarily hold closed the arcing joint.

Another area that appears questionable on visual inspection are two power pins on USB1 though these are apparently not causing a problem yet.
 

Thread Starter

Intrepid-code

Joined Oct 31, 2020
8
If it was exposed to wrong polarity, it may be fried. You could try replacing the controller chip. Sometimes they act like fuses and protect the rest of the IC's on the board. Of course, there are 3 other IC's that may also be affected. If you can read the part numbers on them, it might help determine the likelihood they were also affected. Replacing all 4 IC's blindly is not worth the effort IMHO.

Do you have any experience with fine pitch IC's? The risk during removal is damage to the existing PCB -- like lifting a pad. That is hard to repair.
Resoldering is easier. A hot air tool makes both steps easier.
Thanks again. I just got a multimeter, am gonna try and take readings on each IC's to see which is faulty. I will update with any findings.
 
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Thread Starter

Intrepid-code

Joined Oct 31, 2020
8
With the caveat that all Pb-free (RoHS) {Reduction of Human Satisfaction} solder joints look bad, the input end (top as shown) of R1 looks like it could be cold, cracked and arcing. This would explain the observed sound and may be visually verified by observing with a magnifier in the dark under load. A second verification would involve pushing down on the joint lightly with a small insulated probe (poking with a stick such as a toothpick) to temporarily hold closed the arcing joint.

Another area that appears questionable on visual inspection are two power pins on USB1 though these are apparently not causing a problem yet.
Thanks sir, am gonna work with your recommendations and update on any findings.
 

Thread Starter

Intrepid-code

Joined Oct 31, 2020
8
If it was exposed to wrong polarity, it may be fried. You could try replacing the controller chip. Sometimes they act like fuses and protect the rest of the IC's on the board. Of course, there are 3 other IC's that may also be affected. If you can read the part numbers on them, it might help determine the likelihood they were also affected. Replacing all 4 IC's blindly is not worth the effort IMHO.

Do you have any experience with fine pitch IC's? The risk during removal is damage to the existing PCB -- like lifting a pad. That is hard to repair.
No sir, i haven't worked on an IC with micro pitch before.

Resoldering is easier. A hot air tool makes both steps easier.
 

Thread Starter

Intrepid-code

Joined Oct 31, 2020
8

jpanhalt

Joined Jan 18, 2008
11,088
The link worked for me, but that was from my old orders and was "best offer." That may be why it didn't work. I was worried about that. Seller was "wowfreeshipping1," but was a US-based shipper. Here is the device: "8582 2 in 1 Soldering Rework Stations SMD Hot Air & Iron Gun Desoldering Welder."

The key part number is 8582. There are probably other identical units with different numbers. The first unit I got shut down completely rather than going to sleep. Dealer was very kind and sent me a new unit without needing to ship old unit back. There's a thread about that model here: https://forum.allaboutcircuits.com/threads/what-do-you-think-of-this-solder-hot-air-machine.172137/
 

Thread Starter

Intrepid-code

Joined Oct 31, 2020
8
The link worked for me, but that was from my old orders and was "best offer." That may be why it didn't work. I was worried about that. Seller was "wowfreeshipping1," but was a US-based shipper. Here is the device: "8582 2 in 1 Soldering Rework Stations SMD Hot Air & Iron Gun Desoldering Welder."

The key part number is 8582. There are probably other identical units with different numbers. The first unit I got shut down completely rather than going to sleep. Dealer was very kind and sent me a new unit without needing to ship old unit back. There's a thread about that model here: https://forum.allaboutcircuits.com/threads/what-do-you-think-of-this-solder-hot-air-machine.172137/
Thank you. I checked it, cheaper than expected. I've carted it and gonna order it when the time is right.
If i may ask, is yours still holding up good?
 
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