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Q500 mainboard factory bodge ?!

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There seems to be a bodge from main power switch to i guess 5v rail regulator ? Is this a factory bodge ? Drone is second hand.
IMG_20181229_222619.jpg
 

WTFDproject

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I've seen that picture, or one similar, before. My memory is that in the other case, the member had found it on either a new board, or a refurb, and was fussing about quality control.
Both ends of that wire are normally hard ground points. I suspect the one of them did not have good ground contact, so the jumper was put in place to produce the same result. The one on the switch end is a fairly common board failure, so odds are pretty good it was the culprit.
 
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I've seen that picture, or one similar, before. My memory is that in the other case, the member had found it on either a new board, or a refurb, and was fussing about quality control.
Both ends of that wire are normally hard ground points. I suspect the one of them did not have good ground contact, so the jumper was put in place to produce the same result. The one on the switch end is a fairly common board failure, so odds are pretty good it was the culprit.
Hey mate, the drone itself is working. but I suspect there might be something wrong with the pwm control for one motor, after putting in new esc it blew mosfets, after replacing themit sounds like the motor is running on 2 phases sometimes, underload there is strong buzzing noise from motor.
 

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Replacing individual mosfets on an ESC is a notoriously lost cause. The problem is the power surge from the initial failure. The blown mosfet(s) are easy to see. What is not so easy, is that the power surge seems to corrupt the programing on the small square processor chip. The chip may look fine, but does not sequence the mosfets properly. The results vary a lot, mostly more blown mosfets, but also rotation issues. Most common after more blown mosfets is motor bump, sometimes tries to run backwards. The description of your situation certainly seems within the possibilities.

There are two mosfets for each motor wire. One Positive, the other Negative. Mosfets blow when they both try to close at the same time. Symptom is that one blows, you replace it, the OTHER blows, you replace it, and the first one blows again. Forever.

The easiest way to fix it is to replace the bad ESC.

Are you sure you don't just have a bad motor?
 
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Replacing individual mosfets on an ESC is a notoriously lost cause. The problem is the power surge from the initial failure. The blown mosfet(s) are easy to see. What is not so easy, is that the power surge seems to corrupt the programing on the small square processor chip. The chip may look fine, but does not sequence the mosfets properly. The results vary a lot, mostly more blown mosfets, but also rotation issues. Most common after more blown mosfets is motor bump, sometimes tries to run backwards. The description of your situation certainly seems within the possibilities.

There are two mosfets for each motor wire. One Positive, the other Negative. Mosfets blow when they both try to close at the same time. Symptom is that one blows, you replace it, the OTHER blows, you replace it, and the first one blows again. Forever.

The easiest way to fix it is to replace the bad ESC.

Are you sure you don't just have a bad motor?
the thing is that i had bought a NEW ESC, and replaced, and the mosfet burned out on that one while not under load lol, i think its something to do with signal from motherboard.
 

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I need to leave the house for awhile, but we need to talk about this. Several possibilities exist, and we need to nail down exactly what is happening. Doubtful the mainboard is the culprit. The main CPU actually has only one wire that controls all 4 ESCs via a coding arrangement. There are a couple other chips on the board, but they don't normally cause an issue. Give me about an hour, and I will be able to help work out a possible answer. Maybe other folks will join in the meantime that can fill in some gaps in my knowledge.
In the meantime, does the affected motor/ESC run normal on the GUI?
 
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I need to leave the house for awhile, but we need to talk about this. Several possibilities exist, and we need to nail down exactly what is happening. Doubtful the mainboard is the culprit. The main CPU actually has only one wire that controls all 4 ESCs via a coding arrangement. There are a couple other chips on the board, but they don't normally cause an issue. Give me about an hour, and I will be able to help work out a possible answer. Maybe other folks will join in the meantime that can fill in some gaps in my knowledge.
In the meantime, does the affected motor/ESC run normal on the GUI?
Sometimes it does run, sometimes it spin for split second and turns off. its random. but the gui doesnt tell anything is wrong with the esc. And by the way the two P channel mosfets burned out the first time, had a day long journey trough my old motherboard pile and found replacements. currently now the motor does the split second spin in gui but runs when using controller (twitchy start as you said tho and weird sound underload)
 
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I need to leave the house for awhile, but we need to talk about this. Several possibilities exist, and we need to nail down exactly what is happening. Doubtful the mainboard is the culprit. The main CPU actually has only one wire that controls all 4 ESCs via a coding arrangement. There are a couple other chips on the board, but they don't normally cause an issue. Give me about an hour, and I will be able to help work out a possible answer. Maybe other folks will join in the meantime that can fill in some gaps in my knowledge.
In the meantime, does the affected motor/ESC run normal on the GUI?
Talking about the bad motor - i dont think so, doesnt smell burned and looks fine without pyshical damage nor the bell, or stator. i have one idea - switch the esc for 1 good and 1 twitchy faulty motor, then do new assignment. if indeed the signal from mobo is bad then ill see it.
 

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That was going to be my second suggestion. The first was going to ask you to turn the "bad" motor by hand. It should be slightly bumpy as it passes the magnets, but should be even all the way around, and feel the same as the "good" motors.
 
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By the way, what time zone are you in. I am in Eastern time zone, US. (GMT-5)
I can confirm that the mobo is not the issue, after switching the esc the other motor with faulty esc twitches. but it doesnt explain what got wrong the first time...
 

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This image is from a 350QX2, not a Q500, but the connections are pretty much the same.
If you need to trace the path, this is a place to start. Please note this drawing is not verified by anyone, and may contain errors.

BLH7901 Main  Chip connections.jpg
 

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I can confirm that the mobo is not the issue, after switching the esc the other motor with faulty esc twitches. but it doesnt explain what got wrong the first time...
sorry, did not see this until after I made that last post.

Switching the esc pretty much also eliminates a problem with the esc wires, and strongly suggests you are wiring the motors correctly. Did you use a different motor connected to the bad ESC?
 
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sorry, did not see this until after I made that last post.

Switching the esc pretty much also eliminates a problem with the esc wires, and strongly suggests you are wiring the motors correctly. Did you use a different motor connected to the bad ESC?
Yes, I switched only the esc's from one side, to the other. First time I actually switched ONLY the signal wires and did a re assignment, and the results were the same. so problem lays in the motor/esc.
 

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You followed the same pattern I do. Pretty much comes down to a bad ESC. I doubt you will be able to salvage the one you have. The mosfets on the positive side are different from the negative side. There are also two different versions of the ESCs commonly found on the Q500.

Is the bad ESC the same version as the good (V4 or V5)?
What is the ID number on the mosfets you replaced?
 
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You followed the same pattern I do. Pretty much comes down to a bad ESC. I doubt you will be able to salvage the one you have. The mosfets on the positive side are different from the negative side. There are also two different versions of the ESCs commonly found on the Q500.

Is the bad ESC the same version as the good (V4 or V5)?
What is the ID number on the mosfets you replaced?
Just checked, My quad has v4 but the one I ordered and got is a version v5. That makes sense because the mosfets were different rating than on the old esc. I replaced the v5 esc with p channel mosfets found on v4 (ao4423 p channel mosfet)
 

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That at least sounds like it's a problem. I don't have any history to judge how much effect mixing them would have. Options seem to be find a good V04, which would be difficult, or another full set of V05s, which would be expensive.
Do you have access to the correct mosfets for your V05? I don't recall ever intentionally mixing ESC versions, but it is possible I did so before knowing there were two versions. I really can't give any credible testimony whether that would be an issue by itself, or not.
 
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That at least sounds like it's a problem. I don't have any history to judge how much effect mixing them would have. Options seem to be find a good V04, which would be difficult, or another full set of V05s, which would be expensive.
Do you have access to the correct mosfets for your V05? I don't recall ever intentionally mixing ESC versions, but it is possible I did so before knowing there were two versions. I really can't give any credible testimony whether that would be an issue by itself, or not.
Well, i watched some videos where they replaced broken esc and no one said mixing versions would be bad, but again, maybe they just didnt know :D And i had a look at carolinadrones and it doesnt say anywhere that a particular esc is v4 or v5, i feel like it doesnt matter. But then again, mosfets are different at the escs... and yes I have access to n channel and p channel mosfets for this esc.
 

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Good that you have some options. I wish I had been of more help, but at least I think we established the issue as ESC vrs mainboard. I will be around for a couple more hours before I turn in for the night. Send me a post if you think I can help with anything.
 

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