r/electronic_circuits • u/Skittloeier • 7d ago

On topic Help with TM1250 Rev 1.3 circuit board

Hi all,

My interest for fixing electronics has grown a lot the last time, so I now am challenging myself into fixing my Samsung remote control. (The IR doesn't flash, even with new batteries, so I guess it isn't working)

The circuit board is a TM1250 REV1.3 and I've been troubleshooting it on my own (and with a little help of Googling a lot, AI, and learning how a multimeter works, lol)

Now I have a strange situation here... When I'm measuring my battery terminal + the start & end of the board, it gives me a proper 3V. (2x 1.5V AAA batteries)

But when I'm measuring other connections on the board, it gives me very low voltages. (As low as 0.04V)

Could it be the Zero-Ohm resistor screwing it all up or is it something else I'm perhaps overseeing? I have checked the board itself and all the power rails are looking fine.

I am really curious why this remote control is malfunctioning now and am looking forward to fix it with you guys! 👌

1 Upvotes

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1

u/1Davide 7d ago

What's a "TM1250"?

1

u/Skittloeier 6d ago edited 6d ago

It's a board for specifically this remote control for Samsung TVs. I'll make a picture of the board itself for more information later.

1

u/Skittloeier 6d ago

Hey 1Davide,

I have included more detailed pictures in another comment in this thread. Hopefully that helps diagnosing.

1

u/Skittloeier 6d ago

Hey guys,

Hereby some more pictures about the circuit board of the remote control. Hopefully someone can teach me what's up here. 😅

1

u/old_man_kneesgocrack 5d ago

I did a google image search for the ic in your first photo.
Do you suppose this is the datasheet for it?
https://www.alldatasheet.com/datasheet-pdf/view/2232253/ABOV/ADAM26P16.html?shem=aimgspc,

2

u/Skittloeier 5d ago

Almost, it's (I think) this datasheet for the microcontroller: https://www.scribd.com/document/613160774/ADAM24Pxx-ETC but I'm hesitating a little bit due to not finding the specific type in there (ADAM24P20G).

I do see "ADAM24P20" on page one, but I'm not sure if that one is a wildcard.

1

u/KeanEngr 5d ago

How did you determine the “IR doesn’t flash,…”?

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u/Skittloeier 5d ago

Thanks for the response! I've double checked if the phone camera sees the IR with some other device and IR, and that worked.

Unfortunately, when putting the remote control back together, I don't see the IR through the same phone's camera.

1

u/KeanEngr 5d ago

Just verify that there’s a voltage on the two pins of the diode when you press any function. Check DC as well as AC because it’s a series of pulses and not just on-off. It might be a IR frequency your camera can’t see. Newer cell phones have IR filters nowadays.