Remote control not powering on! Help me please!

[DroneFisherMan]

Hi All,

i am using bayangtoys X16 GPS drone.
I managed to solder the "alfa APA-M04 7 dBi gain RP-SMA directional panel antenna Wi-Fi" on the board, and it was working absolutely fine. Until, I put hot glue on the antenna's solder to make it more solid.

Since then , when I power on the remote the red light comes on for a second and beeps then it goes off. I removed the hot glue and still its doing same thing..

Have I burnt the Tx?

I have checked for any short on the antenna's ground and main wire, there is no short there. I have checked the battery and power, and all looks good.

Could anyone help me out please!

Link to video explaining the issue https://vimeo.com/290456327

 

[d123]

Hi,

Is the glue around the base of that board meant to be there? It seems to cover a few components and may be shorting something out, but in principle it shouldn't be electrically conductive. I'd get a magnifying glass, or portable usb microscope if you have one, and check there are no solder bridges between those components at the bottom of the vertical board, just to be sure. It maybe depends on how hot the glue comes out but I think most solder melts at over 200ºC and these glues from 60ºC to 200ºC from what I just read so I'd be surprised if it could melt solder.

If you think there's a short/bridge, you could also try continuity testing between "safe" components, e.g. the LED pins or resistor to resistor etc. The ICs are not a good idea to continuity test between pins.

Tricky and unreliable but sometimes insightful is to measure capacitance onboard - if capacitor values - are known to gauge if one has been damaged from heat, SMD ceramic capacitors are easy to damage especially when going from cold to hot suddenly.

 

[DroneFisherMan]

Hi,

Is the glue around the base of that board meant to be there? It seems to cover a few components and may be shorting something out, but in principle it shouldn't be electrically conductive. I'd get a magnifying glass, or portable usb microscope if you have one, and check there are no solder bridges between those components at the bottom of the vertical board, just to be sure. It maybe depends on how hot the glue comes out but I think most solder melts at over 200ºC and these glues from 60ºC to 200ºC from what I just read so I'd be surprised if it could melt solder.

If you think there's a short/bridge, you could also try continuity testing between "safe" components, e.g. the LED pins or resistor to resistor etc. The ICs are not a good idea to continuity test between pins.

Tricky and unreliable but sometimes insightful is to measure capacitance onboard - if capacitor values - are known to gauge if one has been damaged from heat, SMD ceramic capacitors are easy to damage especially when going from cold to hot suddenly.

I have rechecked there is no glue.
The glue which you are referring to was there since the beginning, the "capacitance onboard" I only put glue on the antenna's solder, nowhere else. If you saw the video, the power does come up but then goes away, if I immediately power it off and power back on, then there is no LED,

However, if I pause for 5-10 seconds the intensity of LED is high, and subsequently low if powered on during less intervals.

May I know how do I check capacitance ?

 

[zsolt1]

hi,
Check the SMD's around the antenna ..Looks like the power supply is dying when the wi fi chip boot's up. Sometimes the cristal also plays tricks

 

[DroneFisherMan]

hi,
Check the SMD's around the antenna ..Looks like the power supply is dying when the wi fi chip boot's up. Sometimes the cristal also plays tricks

Man, thanks for replying, I am all over the internet looking for some help. it means a lot to me when you are taking time to help me out.

I cleaned the entire board.
What else can I do to fix this?

 

[d123]

Hi,

You can measure capacitance with a multimeter that has that setting or maybe an LCR meter but not so sure whether it's the same as a DMM on a circuit as opposed to measuring individual components.

You could switch it on and measure different points on the board to see if the voltages seem sensible or unusual, and the same for currents extrapolated from voltages across resistors and guess from there, sorry I can't be of more help. I have a wallplug power supply that went on for a second then shutdown and repeated that action because it developed an issue with an electrolytic capacitor, I assume it was a short that triggered some safety feature.

 

[DroneFisherMan]

Man, thanks for replying, I am all over the internet looking for some help. it means a lot to me when you are taking time to help me out.

I cleaned the entire board.
What else can I do to fix this?

Do you think it could be this PA chip?

- - - Updated - - -

hi,
Check the SMD's around the antenna ..Looks like the power supply is dying when the wi fi chip boot's up. Sometimes the cristal also plays tricks

Do you think it could be this PA chip?

 

[zsolt1]

HI,
I also suspect a capacitor .Thous that chip could also be faulty. I would put a voltmeter on the power supply of the board to see any change during startup ....

 

[DroneFisherMan]

HI,
I also suspect a capacitor .Thous that chip could also be faulty. I would put a voltmeter on the power supply of the board to see any change during startup ....

I was just checking the board and realized that when the power is switched on the power button is getting SUPER HOT!!

I can't even put my finger on it... its that hot. (Its that silver rectangular metal switch)

I might be wrong, but is the power getting cut because of the temp getting high?

 

[d123]

Hi

Possibly. It depends on the circuit/IC control features. If it's (very) hot, it might have too much current passing through it. If this suggestion is haphazard, I hope someone will say so: Maybe measure the resistance across the switch when on but unpowered, then measure the voltage across the power switch (in terminal to out terminal) when powered and we can try and guess if the voltage looks like an indicator of excessive current flowing through it.

Have you checked to see if any capacitors are damaged? Do you have access to capacitors to replace them? I agree with zsolt1 and think a sensible place to start is checking the capacitors - they are a weak link in circuits in my little opinion. If a capacitor was overheated somehow or suddenly heated during the gluing task, dead capacitor.

A safe continuity test could be measuring across the pushbuttons when unpowered as well in case they are damaged.

 

[DroneFisherMan]

Hi

Possibly. It depends on the circuit/IC control features. If it's (very) hot, it might have too much current passing through it. If this suggestion is haphazard, I hope someone will say so: Maybe measure the resistance across the switch when on but unpowered, then measure the voltage across the power switch (in terminal to out terminal) when powered and we can try and guess if the voltage looks like an indicator of excessive current flowing through it.

Have you checked to see if any capacitors are damaged? Do you have access to capacitors to replace them? I agree with zsolt1 and think a sensible place to start is checking the capacitors - they are a weak link in circuits in my little opinion. If a capacitor was overheated somehow or suddenly heated during the gluing task, dead capacitor.

A safe continuity test could be measuring across the push-buttons when un-powered as well in case they are damaged.

I also believed that its the damaged capacitor, because the power stays for a short while, capacitor looks to be the main culprit.
But I don't see any puffiness on the 2 capacitors, 1 next to the power switch and 1 next to RF chip

 

[d123]

Hi,

It looks like there are SMD capacitors on that board, too. They don't necessarily show external signs of damage; I find a circuit working oddly or turning off at power-up can be related to the SMD ceramic or other dielectric parts.