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Tommy R · 05-09-2011, 08:35 PM

Hey folks,

Tonight I powered up my truck and when running through a BEC set to 7.4v, I was getting no response from my Hitec 7950 steering servo. So I plugged the servo straight into the receiver and bypassed the BEC. The servo shook violently back and forth as soon as it was powered up!! I've never seen anything like it. I've run this servo on and off the BEC and never experienced this before.

Anyone have a clue what may be going on? When powered through the BEC, I get nothing. When powered via the rx, it shakes violently.

Thanks!

Wasp26Jim · 05-09-2011, 08:45 PM

i'd look at the contacts where the 3 wire end of the bec is soldered to the bec board, mine was poorly soldered.

Tommy R · 05-09-2011, 08:53 PM

Quote:

Originally Posted by Wasp26Jim

i'd look at the contacts where the 3 wire end of the bec is soldered to the bec board, mine was poorly soldered.

I verified 7.4v coming from the BEC so it's good. But when running off the 6v through the receiver it twitches like mad!

Wasp26Jim · 05-09-2011, 08:56 PM

what tx/rx you runnin?

Tommy R · 05-09-2011, 08:58 PM

Quote:

Originally Posted by Wasp26Jim

what tx/rx you runnin?

It's a Futaba 4PL. I've tried different servos, different channels, etc. The only issue at this point is the servo itself. When powered through the BEC it does absolutely nothing. When powered through the rx it twitches violently back and forth.

Wasp26Jim · 05-09-2011, 09:04 PM

id say if the servo's connector is in good working order and wires are in the correct position you probably got a bad servo

heyok · 05-09-2011, 11:00 PM

Maybe the pot in the servo has gotten noisy. It is just like on an old radio where you turn up the volume slowly and you hear the crackling sound. This can be caused by a worn out pot and / or dirt inside the pot (hard to get dirt in there because they seal them up so well now. Sometimes if you can run the pot back and forth a bunch of times it will help clear it up - if indeed this is the problem.

Chappy4o · 05-09-2011, 11:27 PM

is your esc plugged in to your rx correctly? i had this happen to me and i found out that i just had my esc connector turned 180*

hope this helps

autoper · 05-10-2011, 02:00 AM

To me this sounds like a connection problem. Sometimes when connecting the 7950 to a weak internal BEC in the ESC (bypassing your external BEC) the servo will shake like you describe.
Try to measure between GND and VCC from the BEC, if ok follow the lignal wire from the servo to the receiver and be shure the connection is good. If this is ok be shure to connect the GND out from the BEC to GND in the receiver.

Frankie G · 05-10-2011, 02:27 PM

Dont chance it. Warranty.

05-09-2011, 08:35 PM	#1
Tommy R I wanna be Dave Join Date: Aug 2008 Location: Austin, TX, USA Posts: 4,273	Hitec 7950 Shaking Violently! Hey folks, Tonight I powered up my truck and when running through a BEC set to 7.4v, I was getting no response from my Hitec 7950 steering servo. So I plugged the servo straight into the receiver and bypassed the BEC. The servo shook violently back and forth as soon as it was powered up!! I've never seen anything like it. I've run this servo on and off the BEC and never experienced this before. Anyone have a clue what may be going on? When powered through the BEC, I get nothing. When powered via the rx, it shakes violently. Thanks!

05-09-2011, 08:45 PM	#2
Wasp26Jim Quarry Creeper Join Date: Sep 2010 Location: Central MN H-Town Posts: 291	i'd look at the contacts where the 3 wire end of the bec is soldered to the bec board, mine was poorly soldered. Last edited by Wasp26Jim; 05-09-2011 at 08:48 PM.

05-09-2011, 08:56 PM	#4
Wasp26Jim Quarry Creeper Join Date: Sep 2010 Location: Central MN H-Town Posts: 291	what tx/rx you runnin?

05-09-2011, 09:04 PM	#6
Wasp26Jim Quarry Creeper Join Date: Sep 2010 Location: Central MN H-Town Posts: 291	id say if the servo's connector is in good working order and wires are in the correct position you probably got a bad servo

05-09-2011, 11:00 PM	#7
heyok I wanna be Dave Join Date: May 2007 Location: Vancouver, BC Posts: 2,379	Maybe the pot in the servo has gotten noisy. It is just like on an old radio where you turn up the volume slowly and you hear the crackling sound. This can be caused by a worn out pot and / or dirt inside the pot (hard to get dirt in there because they seal them up so well now. Sometimes if you can run the pot back and forth a bunch of times it will help clear it up - if indeed this is the problem.

05-09-2011, 11:27 PM	#8
Chappy4o Rock Crawler Join Date: May 2010 Location: Albuquerque Posts: 821	is your esc plugged in to your rx correctly? i had this happen to me and i found out that i just had my esc connector turned 180* hope this helps

05-10-2011, 02:00 AM	#9
autoper Newbie Join Date: May 2011 Location: Sandnes, Norway Posts: 6	To me this sounds like a connection problem. Sometimes when connecting the 7950 to a weak internal BEC in the ESC (bypassing your external BEC) the servo will shake like you describe. Try to measure between GND and VCC from the BEC, if ok follow the lignal wire from the servo to the receiver and be shure the connection is good. If this is ok be shure to connect the GND out from the BEC to GND in the receiver.

05-10-2011, 02:27 PM	#10
Frankie G Rock Stacker Join Date: Jan 2011 Location: The Olympic Peninsula, Port Hadlock,WA Posts: 76	Dont chance it. Warranty.

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Thread: Hitec 7950 Shaking Violently!