LED light issue

[ntec]

You need to trace the power from battery to LEDs.

Battery -> Power control circuit -> LED strings.

Where is the switch?

Here is pics showing the switch.

[truclacicr]

You need to trace the power from battery to LEDs.

Battery -> Power control circuit -> LED strings.

Where is the switch?

[ntec]

I think both boost converters are passing current into the LEDs, but some LEDs have a lower threshold for illumination than others. I would disconnect the battery, then measure the resistance between Vin and B+, IC ground and B-, Vout and LEDC+/LEDW+, IC ground and LEDC-/LEDW-.

I would also trace the circuit at the on/off switch. Does it physically interrupt the power, or is it a soft switch?

When you said to measure resistance on vin, vout and ic ground which chip am i measuring from and the power switch is a potentiometer where you turn it to power on and increase/lower led intensity.

[truclacicr]

I think both boost converters are passing current into the LEDs, but some LEDs have a lower threshold for illumination than others. I would disconnect the battery, then measure the resistance between Vin and B+, IC ground and B-, Vout and LEDC+/LEDW+, IC ground and LEDC-/LEDW-.

I would also trace the circuit at the on/off switch. Does it physically interrupt the power, or is it a soft switch?

[stj]

a buck/boost converter will pass current even if it doesnt run, so you need to actually cut the feed to one and not just use the enable pin.
i think thats what is happening - one of the boost convertors is passing the battery voltage to the leds when the controller is disabled.

[truclacicr]

Doesn't this mean that the white and yellow LED strings are always on and that the 7.2V (?) battery is being continually drained?

Doesn't this also mean that the light has been configured for yellow light mode? Do you get different readings in white light mode?

If 11V is the supply voltage for each LED string at max brightness, how many LEDs are in each string?

[ntec]

I would start by measuring the voltage between the battery terminals. Then measure the voltage between the LEDW+ and LEDW- terminals, and between the LEDC+ and LEDC- terminals. Do this when the light is on and off.

Lights off ledc- and ledc+ 7.89v
Lights off ledw- and ledw+ 7.78v

Lights on ledc- and ledc+ 10.3v at lowest brightness and max brightness 11.37v
Lights on ledw- and ledw+ 7.83v at lowest brightness and max brightness 7.6v

[R_J]

Are there any components on the back side of the led panel?

[truclacicr]

I would start by measuring the voltage between the battery terminals. Then measure the voltage between the LEDW+ and LEDW- terminals, and between the LEDC+ and LEDC- terminals. Do this when the light is on and off.

[ntec]

maybe the 2 sot23's on the front are fets,
why does it have a stripline antenna?
is it bluetooth controlled or something?

There's no bluetooth but the lights come with a small remote to control lights.

[stj]

maybe the 2 sot23's on the front are fets,
why does it have a stripline antenna?
is it bluetooth controlled or something?

[truclacicr]

Si24R1 is a wireless transceiver.

http://www.szczkjgs.com/UploadFiles/...652/Si24R1.pdf (Si24R1 datasheet)

https://www.easy-core.com/file-download-530-left.html (module)

Those two SOT23-5 ICs look promising, but I haven't been able to identify them. Is the marking "|128" or "|12B"?

Edit:

Nope, "12B" is an op amp.

https://www.ti.com/lit/ds/symlink/tlv333.pdf (TLV333IDCKR datasheet)

https://pt.aliexpress.com/item/1005007900820691.html (photo)


I'm stumped.

[ntec]

PAN3030P would be the MOSFETs in the battery charger circuit.

http://www.jg-semi.cn/uploads/admin/...6/PAN3030P.pdf

Are there any components on the underside of the PCB or anywhere else? I would think that there must be a MOSFET switch, or physical switch, between the battery's positive terminal and the Vin pins of each of the MP3429 boost converters, otherwise the battery would drain through the LED strings.

Perhaps the two MOSFETs at the USB ports are configured as ideal diodes to prevent the battery from back-feeding into the ports? In fact they appear in the simplified application schematic on page 2 of the datasheet.

Here are pics of the back and chips.

[truclacicr]

PAN3030P would be the MOSFETs in the battery charger circuit.

http://www.jg-semi.cn/uploads/admin/...6/PAN3030P.pdf

Are there any components on the underside of the PCB or anywhere else? I would think that there must be a MOSFET switch, or physical switch, between the battery's positive terminal and the Vin pins of each of the MP3429 boost converters, otherwise the battery would drain through the LED strings.

Perhaps the two MOSFETs at the USB ports are configured as ideal diodes to prevent the battery from back-feeding into the ports? In fact they appear in the simplified application schematic on page 2 of the datasheet.

[ntec]

Datasheets ...

https://energo-shop.com/content/file...t-24915618.pdf (IP5389)

https://www.monolithicpower.com/en/d...cument_id/1189 (MP3429)

https://socmcu.com/en/files_down.php?id=44 (SC92F7423X)

https://op1.0ps.us/pdf/opplanet-olig...manual-pdf.pdf (user manual)

I can't see how the intensity of the LEDs is controlled. Perhaps I've identified the wrong converters?

Those chip numbers are the correct numbers shown on my chips. I also have 6 chips on the board labeled pan3030p as shown in pic below.

[truclacicr]

Datasheets ...

https://energo-shop.com/content/file...t-24915618.pdf (IP5389)

https://www.monolithicpower.com/en/d...cument_id/1189 (MP3429)

https://socmcu.com/en/files_down.php?id=44 (SC92F7423X)

https://op1.0ps.us/pdf/opplanet-olig...manual-pdf.pdf (user manual)

I can't see how the intensity of the LEDs is controlled. Perhaps I've identified the wrong converters?

[ntec]

i see it has 2 boost convertors to drive the leds,
they must be powered by fets but that fucking black soldermask makes it impossible to see the tracks

I know can't see the tracks with the black. It's weird cause how come only 3 of the rows of leds are dimly lit when off and not the rest.

[stj]

i see it has 2 boost convertors to drive the leds,
they must be powered by fets but that fucking black soldermask makes it impossible to see the tracks

[ntec]

maybe it has 2 problems.
not turning off fully could be a leaky fet or a bad resistor on the fet,
lets see the boards

the other thing is the leds not all lighting together - it could be uneven leds but i would resolder those smd resistors

I did reflow the resister solder joints but issue is still there.

[ntec]

maybe it has 2 problems.
not turning off fully could be a leaky fet or a bad resistor on the fet,
lets see the boards

the other thing is the leds not all lighting together - it could be uneven leds but i would resolder those smd resistors

here is a picture of the board.