EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: icezebra on February 07, 2023, 08:37:32 pm
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I have tried a lot of things, such as the ideas discussed in:
https://www.eevblog.com/forum/chat/(tips)-how-to-identify-smd-devices-from-the-marking-codes/msg4683560 (https://www.eevblog.com/forum/chat/(tips)-how-to-identify-smd-devices-from-the-marking-codes/msg4683560)
However I cannot identify this TSOT23 six pin device (SOT23-6) with marking code 05 or O5
It might be a TVS, or a Linear Regulator, or a FET.
It is NOT TVS SMS05
Also, what is the long black thing marked EAUE in the second photo?
Help!
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It looks like the bottom 3 pins are connected together, so that makes me think it may be a n-channel mosfet on npn transistor.
As for that rectangular black part, it makes me think it's be a shock sensor or orientation sensor, maybe to detect drive falling or something like that.... but it's much more likely it's just an oscillator / crystal, based on the two ceramic capacitors that seem to be connected to the pads at the end
The chip under it is probably a 2 gbit slc nand chip from Micron.
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The Micron chip is MT29F2G01ABAGDWB-IT:G.
https://www.micron.com/support/tools-and-utilities/fbga?fbga=nw874 (https://www.micron.com/support/tools-and-utilities/fbga?fbga=nw874)
https://nand.gq/#/decode?pn=NW874 (https://nand.gq/#/decode?pn=NW874)
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Much obliged for the responses so far.
I should mention that the chip next to the "05" SOT23-6 devices is an SMPS synchronous buck controller MP1657 with two internal MOSFETs. One internal MOSFET is doing the function of the free wheeling diode in a normal buck converter and the other is the "switch" in a normal buck converter. I have no idea what the external SOT23-6 "05" devices are, but I do not think they can be operated by the MP1657 (for which I append the datasheet.)
On other places on this PCBA there are linear regulators near the SMPS presumably to further regulate the output of the SMPS. There are a total of 6 SMPS and 2 Linear regulators on this PCBA not including the two 05 devices. Cray-cray. See new photos attached for more detail.
https://en.wikipedia.org/wiki/Buck_converter
Also, your are correct, that IS a FLASH device. This PCBA is the main Linux Processor PCBA of a Reolink RLC-510WA IP Camera. I think it has both NAND and NOR Flash onboard.
So the black thing is likely a crystal then. Good observation with the caps and the proximate FLASH device. I don't think it is an orientation sensor but I suppose it could be a reed switch or a shock sensor. I will stick a scope on it if I get the PCBA working again, and update this thread with the result. The MP1657 has failed and I ordered a new one today. I was trying to determine what the 05 devices were in case I also need to replace them. Since they could be FETs I was reluctant to probe them without knowing the pinout.
More info here: https://ipcamtalk.com/threads/reolink-hardware.68214/
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MP1657 Datasheet
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Could those be protection devices for the SD card, perhaps an ESD diode array (3 signal lines per chip)?
There is a row of 7 pads behind the card socket on the other side. I suspect there will be continuity between each signal pad and one of the "05" pins.
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@mariush, thanks to your insight with the capacitors I have identified the back EAUE thing as a "Low Load Patch Crystal" part number MC-146
https://www.aliexpress.com/item/1005002886890490.html (https://www.aliexpress.com/item/1005002886890490.html)
https://www5.epsondevice.com/en/products/crystal_unit/mc146.html (https://www5.epsondevice.com/en/products/crystal_unit/mc146.html)
@fzabkar that is some brilliant detective work. I suspect your are very likely correct. I will measure the devices with a diode checker. I will not have access to them again until March. In the interim, I will search the diodes on Ali-Express!
Thank-you to both of you for taking a genuine interest in this, I greatly appreciate your kind assistance.
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I want to say SRV05.
On-Semi and LittleFuse and Semtech all make it with different markings. The Semtech marking is V05
https://www.aliexpress.com/item/1005004126847506.html (https://www.aliexpress.com/item/1005004126847506.html)
https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/44000000MCn6/BeAzV1kgq8LEQB.FR71VkMB1v3NUxVrSyFjXw9p4pnk (https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/44000000MCn6/BeAzV1kgq8LEQB.FR71VkMB1v3NUxVrSyFjXw9p4pnk)
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@mariush, thanks to your insight with the capacitors I have identified the back EAUE thing as a "Low Load Patch Crystal" part number MC-146
https://www.aliexpress.com/item/1005002886890490.html (https://www.aliexpress.com/item/1005002886890490.html)
https://www5.epsondevice.com/en/products/crystal_unit/mc146.html (https://www5.epsondevice.com/en/products/crystal_unit/mc146.html)
Congratulations. I was thinking that it may be a "tuning fork crystal" or "watch crystal".
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I can't find a component in a SOT23-6 package marked 05, maybe a compatible part for SMS05. :-//
https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/2R0000001OfW/uM7qnDGNH0YlhXQ3LfpChJNLPGRP1iIkH1Mh_q3hrxM
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I can't find a component in a SOT23-6 package marked 05, maybe a compatible part for SMS05. :-//
https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/2R0000001OfW/uM7qnDGNH0YlhXQ3LfpChJNLPGRP1iIkH1Mh_q3hrxM (https://semtech.my.salesforce.com/sfc/p/#E0000000JelG/a/2R0000001OfW/uM7qnDGNH0YlhXQ3LfpChJNLPGRP1iIkH1Mh_q3hrxM)
Indeed professor @gamalot indeed!
An equally probable candidate to the one last proposed (SRV05). The reason I ruled SMS05 out in the first post was because the marking is 05/05.
https://www.aliexpress.com/item/4001089229496.html (https://www.aliexpress.com/item/4001089229496.html)
In hindsight, perhaps that was a bit hasty, as the SRV05 fits no better, with a marking of V05.
https://www.aliexpress.com/item/1005004126847506.html (https://www.aliexpress.com/item/1005004126847506.html)
They both have a similar pinout, with one measurable difference. On SMS05, there is a short between pins 2 and 5. Therefore, as soon as I can get an ohm meter on it (March 2023) I shall report the outcomes, including possible connection to the SD card as postulated by Dr. @fzabkar
I am greatly encouraged by all the engagement and support in this thread. It is a rather pedestrian challenge, yet you have all deployed the full force of your deductive reasoning and SMD marking research skills. As as a result we have had some breakthroughs and some great leads to be followed up, not to mention the learning and skill/knowledge transfer that has occurred as a result, which benefits all members of this forum as well as future Googlers.
Sir Isaac Newton summed up this sort of community support and intellectual tag-teaming rather nicely:
https://en.wikipedia.org/wiki/Standing_on_the_shoulders_of_giants (https://en.wikipedia.org/wiki/Standing_on_the_shoulders_of_giants)