Cheap "high voltage" esc Quest

[rschoi_75]

Bad news fellas. I think I smoked mine today.

I went to the park again today and got in about 5 minutes before it died on me. I most definitely thermalled the esc, because when I checked it, the heat shrink surrounding the esc was melted out of shape. I also lost power to my servo, which leads me to think the ubec is toast, but I need to check that one later tonight. I was running a 5s lipo and 16/48 on the gearing. It performed perfectly two days ago, and for almost 20 mins solid with no problems. So I don't know what went wrong today????

As far as the esc goes, I don't know what blew. Maybe a cap, but not sure since I don't know electronics. I'll take some pics of the damage later tonight or tomorrow, but I guess the MM is going back in the buggy now.

snellemin, did you get yours figured out?

[sikeston34m]

Originally Posted by rschoi_75

Bad news fellas. I think I smoked mine today.

I went to the park again today and got in about 5 minutes before it died on me. I most definitely thermalled the esc, because when I checked it, the heat shrink surrounding the esc was melted out of shape. I also lost power to my servo, which leads me to think the ubec is toast, but I need to check that one later tonight.

As far as the esc goes, I don't know what blew. Maybe a cap, but not sure since I don't know electronics. I'll take some pics of the damage later tonight or tomorrow, but I guess the MM is going back in the buggy now.

snellemin, did you get yours figured out?

Hi,

Check it out. You might get some "warranty" coverage but I doubt it.

If you can't get the seller to stand behind it, take some pics of the carnage and give me a good description. I might buy it from you if you give me a good deal.

I'm really curious about the construction of this ESC. I might be interested if the brain board is still good.

I wonder what happened to it? Hmmmmm......

[rschoi_75]

Hey Sike,

Thanks for the suggestion. I emailed the seller and will see what he says. Not a huge deal for me since I knew from the start it was a questionable purchase.

I am, however, very curious to know what went wrong. Here are some pics, but until I hear from the seller, I can't take any pics of the brainboard w/o the heat shrink. I know you can't see much with the heat shrink in place, but it may give the seller a reason to void my claim. If he says "no", then maybe I can send it to you to take a look at. I'll send you a pm with more details if I get shot down by the seller.

- Rich

[sikeston34m]

Originally Posted by rschoi_75

Hey Sike,

Thanks for the suggestion. I emailed the seller and will see what he says. Not a huge deal for me since I knew from the start it was a questionable purchase.

I am, however, very curious to know what went wrong. Here are some pics, but until I hear from the seller, I can't take any pics of the brainboard w/o the heat shrink. I know you can't see much with the heat shrink in place, but it may give the seller a reason to void my claim. If he says "no", then maybe I can send it to you to take a look at. I'll send you a pm with more details if I get shot down by the seller.

- Rich

I understand.

Is there any signs of melting heat shrink on the mount? (velcro side?)

It looks like some blown FET's from what I can tell. The power board went poof. Hmmmm...........

I like how these are laid out. The power board is nicely arranged. I was hoping these would kick butt. I've been watching them for awhile.

Thanks for the Pm, in advance. I appreciate that.

I would like to know what went wrong too.

[sikeston34m]

Are those Caps Bulging?

[snellemin]

I haven't messed with mine yet. Kinda busy here at work now. Motherboards are getting reworked, so my ESC got to wait now. Modellfun did say that they would replace mine if I shipped it back to them.

[rschoi_75]

Yeah, one is big time. I think it ruptured b/c there is some sticky liquid on top of the cap.

[sikeston34m]

I still think this could be a VERY good ESC with some mods.

It's pretty obvious it is lacking in the cap department. This means the powerboard is catching some pretty big spikes. Especially at the instant the caps fail.

I have some higher voltage FET's that I believe are the same size as the ones used on that power board. I'm very curious about this.

[sikeston34m]

Is the bottom melted? Not the heat sink side.......the other side.

[rschoi_75]

No, the bottom is fine and the motor lead side is fine. The only damage I can see with the heat shrink in place is the caps and the side of the powerboard where the heat shrink melted.

[torqeroll]

i have one for sale with the programer, if some one is interested ??? PM for price

Edited by Serum; prices only discussed by PM or email.

[torqeroll]

sorry, i didnt know

[rschoi_75]

Ok, I just heard back from Modellfun and they offered to replace my esc. Good news. It shows that they are not just a chop shop. However, in the interest of science, I've sold off my esc to Sikeston34m so he can run some experiments on them.

[sikeston34m]

I received the ESC in the mail today. Thanks.

I cut the shrink off and took a look.

The power board looks ok. I haven't removed the heat sink, but I can see the edge of each FET and they look fine. Usually when a FET goes, it makes a mess.

The caps are bulging and the insulation on their leads is almost fried off. There are 2 of them and they are rated at 35v @220uf. These are VERY small IMO. It would do much better with larger ones or at least multiples of these. About 5 of them at least instead of 2.

The Brain board has problems. It smells burnt. I can see one small component that is fried. I will spend some time carefully unsoldering and lifting the power board to discover exactly what the problem is.

Here's what I think. The BEC circuit on the power board is gone. This has dropped power to the brain board. Thus making it "brain dead". LOL

To test this theory, I was hoping it would become functional being powered with an external BEC. No Dice. So the internal BEC isn't even putting out enough power for the Brain to function.

With external BEC power, the brain board heats up quickly. It definately has a BEC problem.

Were you using an External BEC with this on 5S? Or just the built in one?

[snellemin]

On mine I used a Ebec, when it blew. When the brain was taken out there was a mess on some of the chips. It looked burn at first, but it was just nasty flux.

Those caps are small huh. The heatsink just pops right off, as it's just sitting on a thermal pad.