What is this board inside my all in one computer for? - Page 1
Forum section: electronics / general

author: Lis_182_evo
author_rank: Newbie
timestamp: November 20, 2024, 09:36:31 am
content: Hi! I found a board in my all-in-one computer that receives power, and that's it. The board is not connected to any other components. What could this be and what role does it serve?

author: Lis_182_evo
author_rank: Newbie
timestamp: November 20, 2024, 09:37:44 am
content: Photo

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 09:42:44 am
content: How and where was it mounted in your all in one computer.It looks like there is some LED on the bottom of the board and it might transmit some data via that?

author: Lis_182_evo
author_rank: Newbie
timestamp: November 20, 2024, 09:47:32 am
content: The board is inside the all-in-one

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 09:57:29 am
content: It is a mystery.You might want to change the title of the thread to get more response to it.Something like "What is this board inside my all in one computer for?" makes more sense.

author: Psi
author_rank: Super Contributor
timestamp: November 20, 2024, 10:01:10 am
content: Very odd, my only thought, other than something dodgy, was some sort of electronic asset tag.So they can be tracked for inventory and information like S/N can be extracted without the PC needing power.It looks to have a IR Tx and Rx led.

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 10:05:57 am
content: Yeah maybe, but the mounting does not show if it is possible to probe it from the outside and with the lid open, like on the photo, the possible IR transceiver is not visible.

author: Whales
author_rank: Super Contributor
timestamp: November 20, 2024, 10:13:12 am
content: Quite a mystery.I also thought an asset tag, but then why the 360R resistor in a really big package over a milled slot? And it's being watched by a LED-phototransistor thing (TCRT1000) from the other side of the board? Huh?I assume the 8-pin SOIC is a microcontroller. It would be nice to see the part number (tip: clear sticky tape on top sometimes helps, as does using a torch at a very shallow angle to the surface).Lis_182 please open the grey box with one hole and tell us what's inside it. Assuming you don't mind damaging this thing.

author: Chalcogenide
author_rank: Regular Contributor
timestamp: November 20, 2024, 10:14:10 am
content: TRCT1000 is a reflective optical sensor, and the other components seem like a buzzer, a dual color(?) LED, an MCU and a buzzer. I don't see any RF stuff, honestly. Is the battery empty?

author: Whales
author_rank: Super Contributor
timestamp: November 20, 2024, 10:16:07 am
content: I'd agree on the bi-colour LED, but not 100% on the buzzer. It could be a gas sensor? But I guess those tend to have more than 2 terminals.Is it just me, or does one of the traces from the battery go to a missing resistor? I wonder if there is another trace from the battery connector or if the whole thing has never done anythingSomeone installed these in computers as a troll.

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 10:21:22 am
content: More close up pictures of the board would help.Also a shot of the computer with the board removed, and indeed the lid removed of the box next to where the mystery board is placed can be of help.

author: Lis_182_evo
author_rank: Newbie
timestamp: November 20, 2024, 10:22:35 am
content: Quote from: Chalcogenide on November 20, 2024, 10:14:10 amYes, the power element is charged. The LED is two-colored: red and green. For example: When I connect the power, the LED first lights up red (once), then green, and then it turns off. A couple of times, when I repeat the operation (disconnecting and reconnecting the power), it lit up: Once red, 2-3 times green, or red-green-red-green-red-green.

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 10:24:21 am
content: Quote from: Whales on November 20, 2024, 10:16:07 amBit of an expensive prank, if done in a large batch of these computers.@Lis_182_evo, what is the make and model of this all in one computer?

author: Lis_182_evo
author_rank: Newbie
timestamp: November 20, 2024, 10:28:01 am
content: Quote from: Whales on November 20, 2024, 10:13:12 amYes, by the way, there is an inscription on the controller: atmelu t1ny 2222mue

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 10:29:20 am
content: Quote from: Whales on November 20, 2024, 10:13:12 amOne of the holes of the TCRT1000 is blocked by this big resistor. Very odd indeed.

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 20, 2024, 10:31:40 am
content: Quote from: Lis_182_evo on November 20, 2024, 10:28:01 amThat is an ATtiny 22 AVR based MCU.https://www.mcselec.com/atmelpdf/attiny22.pdf

author: coppercone2
author_rank: Super Contributor
timestamp: November 20, 2024, 10:52:32 am
content: do you notice anything about the computer when its removed?does it emit RF energy? Perhaps probe it with a shorted oscilloscope probe to see if you can catch a chirp or something

author: Lis_182_evo
author_rank: Newbie
timestamp: November 20, 2024, 10:56:13 am
content: Quote from: coppercone2 on November 20, 2024, 10:52:32 amIt works as expected, because this board is not connected to other components in the PC.I've disassembled many all-in-ones and laptops. This is the first time I've seen something like this.

author: coppercone2
author_rank: Super Contributor
timestamp: November 20, 2024, 10:59:52 am
content: Could it be a sensor to detect access for a warentee?I think it would be prudent to figure out how to bypass such a sensor

author: Psi
author_rank: Super Contributor
timestamp: November 20, 2024, 11:48:09 am
content: I wonder if it's just optically counting something.Like insert/removal of something, or syncing to day/night cycles to count number of days in service after removal from shipping box.Could be very crudely trying to detect high levels of some types of radiation by means of two optical sensors one with a higher density object blocking it (that resistor) for signal comparison. Maybe for warranty reasons to confirm laptop never went through those really high energy x-ray systems that sterilize mail and some facilities.What is the metal square thing that it's next to?

author: SeanB
author_rank: Super Contributor
timestamp: November 20, 2024, 11:59:49 am
content: Definitely a warranty tag, likely used during the warranty period to hold information, as it has a serial EEPROM attached, so you use an IR communicator to recover things like serial number, as built info, Windows key and other system serial numbers. Makes it easier during any warranty work to simply scan this off, and poopulate the repair order form, and then compare to the as built to see if there are any "unauthorised" upgrades, or if they need to replace any parts, or for reinstall with a new blank drive.

author: MathWizard
author_rank: Super Contributor
timestamp: November 22, 2024, 11:37:54 pm
content: Isn't it a little battery, wrapped up in black plastic/rubber, and the chips would be a charging circuit ??

author: coppercone2
author_rank: Super Contributor
timestamp: November 23, 2024, 08:01:23 am
content: its pretty close to that speaker

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 23, 2024, 08:13:42 am
content: Quote from: MathWizard on November 22, 2024, 11:37:54 pmYes, the round thing is a battery, but the circuit has been identified as a MCU with an IR transceiver, so I doubt it being a charging circuit for that battery. There are no other connections to this small board.Quote from: coppercone2 on November 23, 2024, 08:01:23 amYes and what is it that you are trying to say with that?That it picks up the changing magnetic field of the speaker and charges the battery with that?Even if the big black part is a coil, there is no additional circuitry to make it a safe charger.

author: u666sa
author_rank: Frequent Contributor
timestamp: November 26, 2024, 04:32:00 am
content: This appears to be one of the stolen ICL SafeRAY's Si105.Mi's.https://wiki.dno-it.ru/2023/04/26/sbornaya-informacziya-monoblok-icl-saferay-si105-mi/No, this is not an asset tag, it's something else. But since it is stolen equipment....

author: Bud
author_rank: Super Contributor
timestamp: November 26, 2024, 05:38:43 am
content: Pagers, ICOM radios, all-in-one computers.It is waiting...

author: MathWizard
author_rank: Super Contributor
timestamp: November 26, 2024, 02:58:39 pm
content: Quote from: pcprogrammer on November 20, 2024, 10:24:21 amSomeone should ask Bill Gates LOL

author: schmitt trigger
author_rank: Super Contributor
timestamp: November 26, 2024, 04:14:08 pm
content: As others have already mentioned, mentioning the all-in-one’s brand and model number will allow us to make more accurate assumptions.EDIT; If you disconnect the board, will the computer continue to operate normally?

author: pcprogrammer
author_rank: Super Contributor
timestamp: November 26, 2024, 08:16:26 pm
content: Quote from: schmitt trigger on November 26, 2024, 04:14:08 pmSee:https://www.eevblog.com/forum/reviews/whats-the-fee/msg5720781/#msg5720781It does not interfere with the normal operation of the computer.Unfortunately the OP has not provided any further information and has not logged in after that last message. So maybe we will never know what the board is for.

author: schmitt trigger
author_rank: Super Contributor
timestamp: November 28, 2024, 12:56:18 am
content: A couple of men in black suits appeared at his doorstep and showed him a flash unit…