ES121 Screwdriver repair - SOT25 SMD ID CYLB

[pa0fot]

Miniware ES121screwdriver failed after charging, behaving erratically and then finally the screen went black after battery was empty.
Return for repair is not realistic given cost of shipping, so trying to repair.
Fortunatelty it was easy to open, see http://zhongce.sina.com.cn/article/view/10177 and Youtube review by Marco Reps (Search for yqlfHeZiRTA ).

After desoldering the battery measured empty indeed (3,7V), but could be charged normally to 4.2V with an external PSU.
Then when reconnecting the charged battery a device near the USB connector got *very* hot *very* quickly, current drawn from the battery was about 420 mA.

So now trying to identify this 5-pin SOT25 component, despite searching haven't found anything so far.

It *might be* an LDO regulator, pin 3 of this device is connected to the battery positive terminal.
The SOT25 device SMD ID is 'CYLB', see attached photos.

Any hints and advice very much appreciated!

Thanks,
Folkert

[fzabkar]

Which is the ground pin?

If you suspect that it is a regulator, try to find where the main chips get their Vcc. I believe that the MX6208 would be powered directly from Vbat, while the display (and the MCU?) would be powered from the switchmode converter next to the coil. The MCU can operate from a supply in the range of 2.0V - 3.6V.

https://datasheet.lcsc.com/szlcsc/Sinotech-Mixic-Elec-MX6208_C155448.pdf (MX6208)
http://www.farnell.com/datasheets/1963088.pdf (STM32F103T8U6)

The same part in your teardown is marked "CYLA", which would suggest that perhaps only the first 3 characters are unique. If it is an LDO regulator, then one would expect to find filter capacitors on the Vin and Vout pins. However, I don't see any.

[sleemanj]

Going from CYLA as indicated by poster above we find this thread

https://www.elektroda.pl/rtvforum/topic2999838.html

a poster indicates they replaced CYLA with https://www.elinfor.com/pdf/Lowpowersemi/LP4054-Lowpowersemi.pdf

which is a typical linear lithium ion charger, you should be able to verify the connections pretty easily to confirm if this is likely, I would not be surprised as it would fit the application.  The A/B/... suffix is probably about charge rate or termination voltage or something would be my guess.

[fzabkar]

The LP4054 appears to be a clone of the LTC4054:
https://www.analog.com/media/en/technical-documentation/data-sheets/405442xf.pdf (LTC4054-4.2)

The BL4054 appears to be another clone of the LTC4054, but it has several versions which differ in their float voltages (4.2V, 4.3V, 4.4V):

http://www.belling.com.cn/media/file_object/bel_product/BL4054B/datasheet/BL4054_V1.4_en.pdf
http://www.belling.com.cn/en/product_list.html?type=106

However, the marking code in the datasheet differs from this example:

https://www.ebay.com/itm/5PCS-2YL6-BL4054-42TPRN-SOT-23-5-800mA-Standalone-Linear-Li-Ion-Free-Reg-Mail-/170917058041

BL4054-42TPRN SOT-23-5 800mA Standalone Linear Li-Ion -- marking 2YL6

Here is another clone (HX4054):

http://www.hjxai.com/data/upload/file/201811/ed0817579441566ec20e01dac3196b73.pdf
https://www.chinahao.com/product/540791253875/ (marking LTH7)

… and another ? (XT4052, 4.2V, marking 3KAL):

http://www.natlinear.com/uploadfiles/2014/XT/XT4052_E.pdf
https://www.yoycart.com/Product/557200427644/

XT4054:
http://www.natlinear.com/uploadfiles/2014/XT/XT4054_E.pdf

TP4054:
http://images.100y.com.tw/pdf_file/38-TP-TP4054x.pdf

EUP8054 (another clone?):
http://www.bdtic.com/DataSheet/EUTECH/EUP8054_EUP8054X.pdf

This is becoming funny:

GP4054 CP4054 IT4054 LP4054 LN4054:
https://ru.aliexpress.com/item/2038984975.html

http://www.sumzi.com/upload/files/2007/09/20070921105939174.pdf (IT4054)
http://www.chipsky.com/data/upload/files/20150917_229.pdf (CP4054)

I just keep finding more of them. :-)))

http://pdf-file.ic37.com/uploadpdf_old/TOREX/SGM4054_datasheet_510122/831897/SGM4054_datasheet.pdf (SGM4054)

http://monitor.espec.ws/files/qx4054_2yl6__180.pdf (QX4054)

This person has found a lot more:

https://www.rcgroups.com/forums/showthread.php?3260351-Battery-Charger-for-Low-mah-Batteries

https://www.st.com/resource/en/datasheet/stc4054.pdf (STC4054, STMicroelectronics)
https://www.rcgroups.com/forums/showatt.php?attachmentid=4635498 (IN4054)
http://www.hmsemi.com/downfile/HM4054_HM4054D.PDF (HM4054)
http://www.haoyu-ic.com/cn/product_content.asp?product_id=50 (HYM4054-4.2)
http://www.techcodesemi.com/datasheet/TD9054.pdf (TD9054)
http://pdf.dzsc.com/20090603/200903070734286606.pdf (KB4054)

Just for completeness, I found the following datasheet for a 3-axis gyroscope, but the number of pins doesn't look right.

https://www.st.com/resource/en/datasheet/l3gd20h.pdf (L3GD20H, marking AGD2)



(alternative photo of AGD2 IC)

[pa0fot]

Many thanks for great effort fzabkar and sleemanj!
It seems very likely close to LTC4054 indeed, hopefully it is pin compatible.
Weird Chinese chip is hard to find indeed.
Wil try to contact the makers of the device, see if they have any advice.
Thanks again to all!

[dretay]

Hi Folkert,

Did you ever resolve this? I'm experiencing exactly the same behavior with my screwdriver. Did you end up swapping out the regulator?

[anda3243]

Hello Forum

I have some questions. I am working on developing on a much better version of this product.

What would be your main complaints and wishes for an improved version of a screwdriver like this? Faster speed? Higher torque? Quality? Charge times?
I  am very interested in feedback from a user perspective.

Thank you, and hope to get some good answers.

Miniware ES121screwdriver failed after charging, behaving erratically and then finally the screen went black after battery was empty.
Return for repair is not realistic given cost of shipping, so trying to repair.
Fortunatelty it was easy to open, see http://zhongce.sina.com.cn/article/view/10177 and Youtube review by Marco Reps (Search for yqlfHeZiRTA ).

After desoldering the battery measured empty indeed (3,7V), but could be charged normally to 4.2V with an external PSU.
Then when reconnecting the charged battery a device near the USB connector got *very* hot *very* quickly, current drawn from the battery was about 420 mA.

So now trying to identify this 5-pin SOT25 component, despite searching haven't found anything so far.



It *might be* an LDO regulator, pin 3 of this device is connected to the battery positive terminal.
The SOT25 device SMD ID is 'CYLB', see attached photos.

Any hints and advice very much appreciated!

Thanks,
Folkert