Is my Quark 125B dead - RC-Monster Forums

Hypersprint · **Is my Quark 125B dead -** 05.22.2008, 08:39 AM

I've got an E-Revo with a 4S1P 5000mah 20C, a Quark 125B and a Feigao 9xl. When I pull the throttle (partial or full does not matter) it will run very slowly for just 1 to 3 seconds and then all lights go out on the Quark. Release the throttle for several seconds and the red light will begin to flash again. I don't know if it is doing some kind of reboot but the tones only chime when the truck is first powered up.

I checked the voltage coming from the Rx and in neutral I got .5v and at full throttle I got .7v, I don't know what I should be getting but the voltage never dropped at any time so I think the Rx is ok.

Apparently there is no place to send it for repair anymore.

What do you think?

Thanks
Rob

BrianG · 05.22.2008, 09:55 AM

0.5v and 0.7v?? Is that the throttle signal cable? If so, that's about right. The signal is a PWM ~50Hz with 1-2ms pulses. So, the duty cycle ranges from about 5-10%. Assuming the voltage rail is 5v, those readings are about right (but depends on the meter's capabilities). You really need an oscilloscope to read the signal right.

Are you running an external BEC or receiver pack? And if so, do you have the ESC BEC disabled (remove red wire from the throttle cable)?

Did the ESC just start doing this after several cycles of normal running, or has this been happening ever since you installed it?

jhautz · 05.22.2008, 09:56 AM

Could it possibly be the the LVC kicking in?

Hypersprint · 05.22.2008, 10:23 AM

Yes, the .5v to .7v was read at the throttle signal cable, I only showed you the 10ths but my little meter displays 1000ths. I did not write the full numbers down but if it would help I can read it again. The truck is using an Rx pack, but until recently the ESC BEC was not disabled. I bought the truck already converted and did not notice that the ESC BEC had not been disabled until shortly after the truck began to run bad after a fairly mild rollover. So, yes the truck use to run like a bat out of you know where.

I don't believe it could be the LVC, I am reading 16.25Vm on my Watts Up meter.

Thanks for your help guys
Rob

Mozzy · 05.22.2008, 10:27 AM

Have you tried a different motor?

If not, always a thought, cause, that speedy is more than capable of handling that battery & motor, but, you may have toasted your motor through incorrect gearing.

Just a thought.

Hypersprint · 05.22.2008, 11:01 AM

Unfortunately, this is my only tuck so I don't have spare parts to try. Wait a minute, can't I use parts out of a brushless plane? at least to rule things out! I'm going to try the ESC out of my plane just to see what happens. It's only rated for 55A so I just need to go easy.

Rob

Mozzy · 11:04 AM

Yeah, try the motor first but don't give it full power, just very gently as you're just testing to see what's not working.

My mate toasted his motor & his MM did a similar thing, but, lucky for my greed or forward thinking I had a new motor for him to test & it was the motor.

Hypersprint · 05.22.2008, 11:47 AM

I tried the ESC out of my plane and everything works great.

I don't believe I didn't think of trying that sooner, both vehicles are sitting on my bench (dining room table) right now.

I guess I will jump in on the bidding for the Quark 125 that GorillaMaxx360 has on EBay, If it goes to high I will just wait until Mike has the MMM in stock. It's to bad that I missed out on both the Pre-sale sales. Would anyone who ordered extra MMM's on sale like to help save a marriage? Unless someone is interested in buying an E-Revo that needs an ESC!!!

Thanks guys

Mozzy · 05.22.2008, 11:51 AM

I'm glad I bought my two up front & also glad you sorted the issue too.