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Electronics => Repair => Topic started by: NickFolino on April 16, 2023, 08:29:46 pm

Title: Help with parts identification - Celestron Microscope repair
Post by: NickFolino on April 16, 2023, 08:29:46 pm

I'm trying to repair a Celestron Microscope.  I believe someone plugged in the wrong power supply and damaged 2 components.  Pictures attached.  Any idea what these parts are?  Any help would be greatly appreciated!

Nick

Title: Re: Help with parts identification - Celestron Microscope repair
Post by: fzabkar on April 16, 2023, 11:28:10 pm

The marking isn't exactly the same, but it's very similar (WS-nnn or WS=nnn):

Richtek, RT8008, 1.5MHz, 600mA, High Efficiency PWM Step-Down DC/DC Converter, 2.5V - 5.5Vin, SOT23-5:
https://www.richtek.com/assets/product_file/RT8008/DS8008-07.pdf (https://www.richtek.com/assets/product_file/RT8008/DS8008-07.pdf)

https://www.google.com/search?q=rt8008&tbs=isz:m,itp:photo&tbm=isch (https://www.google.com/search?q=rt8008&tbs=isz:m,itp:photo&tbm=isch)
https://www.google.com/search?q=ws+sot23-5&tbs=isz:m,itp:photo&tbm=isch (https://www.google.com/search?q=ws+sot23-5&tbs=isz:m,itp:photo&tbm=isch)

If you could provide a full photo, that would enable us to see the parts in context.


WS- is RT8008PB (Lead free)
WS= is RT8008GB (Green)

http://www.smdmark.com/en-US/search/code?id=ws- (http://www.smdmark.com/en-US/search/code?id=ws-)
http://www.smdmark.com/en-US/search/code?id=ws= (http://www.smdmark.com/en-US/search/code?id=ws=)

Title: Re: Help with parts identification - Celestron Microscope repair
Post by: NickFolino on April 17, 2023, 12:25:35 am

Thanks!  Here's the circuit.  5VDC comes in at the connector on the left. U5 and U22 are the damaged components I'm trying to identify.

Nick

Title: Re: Help with parts identification - Celestron Microscope repair
Post by: fzabkar on April 17, 2023, 01:04:03 am

Assuming RT8008 is the correct part, and if R11 and R12 are 30D (200kohm) and 01D (100kohm), respectively, then the output voltage of U22, when measured at L4, would be 1.8V.

The part marked DE= appears to be a 3.3V LDO regulator.

RT9193-33GB, Richtek, 300mA, 3.3V, Ultra-Low Noise, Ultra-Fast CMOS LDO Regulator, marking DE=, SOT23-5:
https://datasheet.octopart.com/RT9193-33GB-Richtek-datasheet-12517944.pdf (https://datasheet.octopart.com/RT9193-33GB-Richtek-datasheet-12517944.pdf)

http://www.smdmark.com/en-US/search/code?id=de%3D (http://www.smdmark.com/en-US/search/code?id=de%3D)

I can't identify U5, but I'm wondering if it is another LDO regulator. I would identify the larger ICs and determine what supply voltages they require. The A106 capacitors appear to be the filters on the Vins and Vouts.


Edit:

Could U5 be a TC1014-2.5VCT713? That's a 2.5V LDO regulator.

TC1014-2.5VCT713, Microchip, 2.5V, 50mA, CMOS LDOs with Shutdown and Reference Bypass, marking A1xx, SOT23-5:
https://ww1.microchip.com/downloads/en/DeviceDoc/21335e.pdf (https://ww1.microchip.com/downloads/en/DeviceDoc/21335e.pdf)

Title: Re: Help with parts identification - Celestron Microscope repair
Post by: NickFolino on April 17, 2023, 10:16:55 am

Yes, fzabkar.  I think that's it!

How did you find these?

Nick

Title: Re: Help with parts identification - Celestron Microscope repair
Post by: fzabkar on April 17, 2023, 04:35:16 pm

http://www.smdmark.com/en-US/search/code?id=a1xx (http://www.smdmark.com/en-US/search/code?id=a1xx)