Solar yard light stopped working

[AncientBeginner]

Hello all,
This is my first post and I have absolutely no idea what electronics is.
Here is what I am facing:
My wife brought solar led lights to place in front yard. They had been working for a while but then they stopped working.
I was intrigued and wanted to see what is going on.
When I opened up the top part which has solar panels, it had a single Ni-Cd cell (AA 400mAh 1.2V).
I thought may be cell is not being charged, so I charged it and tried to turn on the lights but nothing happened.
Then I stripped one light bulb from the panel and tried to turn that on, still it did not work.
So I wondered what is going on, I then used 2 Ni-Cd cell (AA 400mAh 1.2V) and connected that single light and it did turn on.
I have a voltage controller I used that, and when I passed 1.5V (300mA max) it lights up single bulb as well as the whole panel.
Now I am wondering what has changed that I can turn on the lights with 1.5 volts or using 2 of 1.2v cells but not with a single one?
Can some kind sole shed some light and help me fix this?
Thanks a lot
I have attached the image that shows the panels front, back and my crude effort to show that 2 cells are lighting the bulb

 

[donkey]

got an ammeter? the battery might not be getting up to full charge

 

[Herschel Peeler]

Hello all,
This is my first post and I have absolutely no idea what electronics is.
Here is what I am facing:
My wife brought solar led lights to place in front yard. They had been working for a while but then they stopped working.
I was intrigued and wanted to see what is going on.
When I opened up the top part which has solar panels, it had a single Ni-Cd cell (AA 400mAh 1.2V).
I thought may be cell is not being charged, so I charged it and tried to turn on the lights but nothing happened.
Then I stripped one light bulb from the panel and tried to turn that on, still it did not work.
So I wondered what is going on, I then used 2 Ni-Cd cell (AA 400mAh 1.2V) and connected that single light and it did turn on.
I have a voltage controller I used that, and when I passed 1.5V (300mA max) it lights up single bulb as well as the whole panel.
Now I am wondering what has changed that I can turn on the lights with 1.5 volts or using 2 of 1.2v cells but not with a single one?
Can some kind sole shed some light and help me fix this?
Thanks a lot
I have attached the image that shows the panels front, back and my crude effort to show that 2 cells are lighting the bulb

The LED probably won't light at 1.2 V. The 8-pin IC may be the answer, Does it have a number on it like LM3909? This is an LED flasher chip that adds a charge on a capacitor to the 1.2 V battery to blink the LED.

 

[BobK]

The solar lights that operate off a single 1.2V battery use a boost converter to up the voltage. You can light the LED directly from two cells producing 2.4V, so all you have proven is that the LED itself is not damaged.

I have fixed two of these and the failure mode was different on each. On had a resistor fail, the other had photocell that senses dark fail.

Bob

 

[AncientBeginner]

The solar lights that operate off a single 1.2V battery use a boost converter to up the voltage. You can light the LED directly from two cells producing 2.4V, so all you have proven is that the LED itself is not damaged.

I have fixed two of these and the failure mode was different on each. On had a resistor fail, the other had photocell that senses dark fail.

Bob

Hi Bob,
I did one more test.
Following your comments, I supplied 1.5V(300mAh) to the actual solar board.and it did turn on all the lights...so if everything on the board is ok, doesn't it should turn on the lights with new battery?
Or may be something very simple is not getting in my head..:-(
Because if solar panels are bad than light should turn on with new batter but it will not recharge the cell..right?

 

[BobK]

That sounds about right. The battery could be bad, or simply not charging. Have you checked the connections to the solar panel?

Bob

 

[AncientBeginner]

No, I bought new batteries, same kind the one is in picture (yellow) and regular 1.2v and 1.5v batteries. But light is not turning on from the batter cell where as if I use my power controller which is in the picture and set the output to 1.5 then light turns on but it doesn't with one cell, may it be 1.2 or 1.5 volt..that is what confusing me...any suggestions please...

 

[BobK]

Did you charge those NiCad batteries after you got them. They generally come uncharged.

Bob

 

[AncientBeginner]

Did you charge those NiCad batteries after you got them. They generally come uncharged.

Bob

Yes tried fully charged one, didn't work, then put fully charged one and a completely new(supposedly uncharged) one (put two together) and lights turn on...
it seems like it does not turn on lights with battery cell even if it is 1.5 v, and if I use my power controller it will turn on with 1.5 v, for batteries, it has to be 2 ...just don't understand....
By the way I am truly thankful for you taking time and responding to me(helping a beginner is never fun)

 

[73's de Edd]

.


Sir AncientBeginner . . . . . .

And YOU call yourself ancient . . .check me out ! . . . . .I just don't happen to fully fit the beginner aspect.

I was initially leaning towards the sole ni cads/mh's also.
BUT do you get almost all day FULL sunlight placement on the cells by their locations ?

Your solar cell cluster of four units only has 2 Volt output and that's not leaving a bunch of "headroom".

But . . .GUESS WHAT . . . . I am still waiting to see how the non supplied identification of the
mystery 8 pin DIP figures into the design scheme of this unit.

HOMEWORK:

Place the photocell in full sunlight and monitor its max current output capability, using DC milliammeter mode of your DMM metering.

Take a supposedly "charged" cell and use your DMM in its 10 DC amps scale and touch probes to the cell ONLY long enough to get a QUICK reading.

If you then read up in the 5 Amps PLUS range . . . .you actually do have a charged cell.

Standing by . . . . . .

73's de Edd


.

 

[AncientBeginner]

.


Sir AncientBeginner . . . . . .

And YOU call yourself ancient . . .check me out ! . . . . .I just don't happen to fully fit the beginner aspect.

I was initially leaning towards the sole ni cads/mh's also.
BUT do you get almost all day FULL sunlight placement on the cells by their locations ?

Your solar cell cluster of four units only has 2 Volt output and that's not leaving a bunch of "headroom".

But . . .GUESS WHAT . . . . I am still waiting to see how the non supplied identification of the
mystery 8 pin DIP figures into the design scheme of this unit.

HOMEWORK:

Place the photocell in full sunlight and monitor its max current output capability, using DC milliammeter mode of your DMM metering.

Take a supposedly "charged" cell and use your DMM in its 10 DC amps scale and touch probes to the cell ONLY long enough to get a QUICK reading.

If you then read up in the 5 Amps PLUS range . . . .you actually do have a charged cell.

Standing by . . . . . .

73's de Edd


.

Thanks for a detail response...however since I don't know anything about the tool "DC milliammeter mode of your DMM metering." you mentioned...:-(
I think I will just buy some new lights(they don't cost much)...I just thought if it were easy then could be interesting project.
Again Thank you very much for your time and every one else who took the time to respond.

 

[73's de Edd]

.



Sir AncientBeginner . . . . . .

I feel that your desire, other than the proper operation of the unit again, would also be expanding your knowledge base and self satisfaction of figuring out the root cause of the problem on your own.
The only other thought would be the stepping in of a friend or acquaintance, more knowledgeable in the fields of electricity or electronics, that could assist you .

Some of us are still curious, what the alpha numeric markings on the 8 pin IC on the circuit board is being.

73's de Edd

 

[AncientBeginner]

the chip has following marking on it
YX861
1108