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..

(That glue near the LED is factory set, it was there since the beginning)

1)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. 2) Battery are tested for voltage and working fine. The board is receiving proper voltage from the battery, I tested the voltage on the board as well.

Could anyone help me out please!

Link to video explaining the issue Video

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closed as off-topic by Chris Stratton, Andy aka, Dave Tweed Sep 22 '18 at 10:56

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?" – Dave Tweed
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    \$\begingroup\$ these two statements contradict each other ....I put hot glue on the antenna's solder and That glue is factory set, it was there since the begining \$\endgroup\$ – jsotola Sep 22 '18 at 3:57
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    \$\begingroup\$ It seems likely to me that you have cracked one or more of the connections between the daughtercard and the main board while applying the hot glue. Try carefully reheating all of the solder joints where the two boards meet. \$\endgroup\$ – Dave Tweed Sep 22 '18 at 10:56
  • \$\begingroup\$ @jsotola : I mentioned about the glue because, I did not want you to confuse that glue with what I had put. \$\endgroup\$ – david bob Sep 22 '18 at 11:14
  • \$\begingroup\$ @DaveTweed : Those two boards do not have any soldering from the side I out hot glue. If you see the PA chip, thats where it is soldered to the main board. \$\endgroup\$ – david bob Sep 22 '18 at 11:17
  • \$\begingroup\$ The little board sticks through a slot on the larger single-sided board. The solder joints are on the other side of the main board (duh!). If you flexed these joints at all while applying or removing the hot glue, you probably cracked some of them. \$\endgroup\$ – Dave Tweed Sep 22 '18 at 11:23

Perhaps you have just loaded critical RF tuning conductors with shunt capacitance of hot-glue and now it fails due to antenna impedance mismatch. They often use small pF values far less than a gob of glue.

The super hot comment implies either total Tx power reflected back or ESD damage from process handling.

  • \$\begingroup\$ That sounds most likley. I’ve corrected the capitalization. \$\endgroup\$ – winny Sep 22 '18 at 10:12
  • \$\begingroup\$ So, may I know how should I fix this problem? Just to give more understanding of the issue, the power light comes on if I leave the power button in off position for 10 seconds or more. If I power it back on after 10 Sec, the light comes up, but if I immediately power it on after 1st time, then the light does not comes on. Did you check the video link I posted? That explains the issue \$\endgroup\$ – david bob Sep 22 '18 at 11:15
  • \$\begingroup\$ Insufficient info and details \$\endgroup\$ – Sunnyskyguy EE75 Sep 22 '18 at 18:55
  • \$\begingroup\$ @TonyEErocketscientist I don't if this helps or not, but the power switch gets super hot if I leave it switched on. \$\endgroup\$ – david bob Sep 24 '18 at 13:13
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    \$\begingroup\$ The video explains nothing of your rework except shows LEDs off and on as you describe near the conductors and small SMD parts that I describe. Super hot implies ESD damage. Or something faulty. \$\endgroup\$ – Sunnyskyguy EE75 Sep 24 '18 at 13:14

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