For those who want the gritty details...
 

National Semiconductor still doesn't have any answers for why SOME of their parts fail, and others work fine.
So we are continuing our own internal investigation, trying to reproduce the failure mode. We are also looking at an alternative to the National part if we cannot determine the source of the issue.

Patrick

Thanks for keeping us up to date. Mine is running so good I am thinking of getting another one to replace my MGM.

Mine still running strong, even after getting mulch into the fan.

Yeah, if we could find out why only 30% of them fail, and then about 30% fail after replacement ----

Very strange indeed. Has this been taking a lot of your time lately? Still able to work on my project any?

Working on it now. :)

http://www.youtube.com/watch?v=GrmTJ...eature=related

nuff said

That chit aint funny.....

His Battery Wires must have been too long! :rofl:

Thanks for the update. So with the 30% failure has it been to do with the components and not the car setups (motor, batt)?

said in a Beavis voice......Fire, Fire......its cool to see it happen unless it belongs to you......:oh:

Well, we haven't been able to find a link between setup and failures at all. That's what is frustrating about this...

Why havent I been contacted about whats going on with the 2nd failed MMM that Castle received 05/29/08.The 1st was fixed and returned with in 1 weeks time.

William Swartz

I don't know -- but you can call in and ask Christy what the status is.

(913) 390-6939

Patrick

Patrick, have you guys been able to duplicate/create any failures at all at your site?

I know how he feels :lol:. Funny thing is that I'm using the same batteries and wires with a new ESC and it's running fine. Mine went up in flames right after it rolled backwards and I gave it some throttle.

HA! My brother used to work at National Semiconductor designing chips. Small world.

Now if I could just get my 2nd Monster to program I'd be happy. It won't find neutral just like DickyT. I've tried 2 3100 receivers and 1 3000 receiver with no luck. It just keeps beeping and flashing the yellow light.

Patrick:My MMM worked for over 90 minutes the first round, then just dead no drama. After getting it back from repair I ran it last weekend about 40 to 50 minutes, durring that time my new spektrum receiver lost lock, the car stopped & the RX light was not right so I re-binded it & all was well for 10 to 15 more minutes. Lost lock again, this time would not re-bind, go home. At home find the fan is borken but still spins and all is well after installing my old spectrum into the car (sent RX back to spektrum). Ran the car today for 30 plus minutes, car stopped. Appears the RX is not working, turn off then on all is well for about 5 minutes then RX stops the car again. Off then on all is well for 2 minutes, car stops BEC is not enough voltage to run the RX. RX works on a battery fine. All of todays action was with a new fan plugged into the RX. It seems to me that even when the MMM is working it might be droping the regulator output voltage periodically? I'm waiting to hear back from spektrum on what killed the RX. I will add that after taking apart the MMM to replace the fan, I do not like the way the wires (all the small ones) are routed over the corner of the bottom of the PCB. The red wire to my fan had alot of wire showing thru the insulation where it was touching the corner of the PCB.

Just more data for ya Patrick. You guys will see my MMM back this week.
I Love the programmablity of the unit.
Mike

Mike,

Thanks for the feedback. That certainly helps -- I'll be interested to see your unit back, and see if we can make it run into shutdown like you did.

We are planning a change to keep the fan wires from rubbing.

I think the fans are failing because the fan rotor gets wedged against the top of the esc case. I found this out putting a novak fan in, a tiny bit of fuel line or some small spacers should fix this. Will try it later and see.

Thanks Patrick for the update. This sort of communication breeds fidelity, as I am sure you know....

The fan gets wedged up so the rotor is hitting the center part of the "cage" freezes the fan and it burns out.

Patrick, I did what FG101C said below & have not broken that fan yet. The blades just get too close to the cover. Also the SMT connector used too connect the fan to the PCB is going to be a problem I think (mine came off when the fan was not even pluged into it).

Thanks for listening
Mike

Ah. Good, two more things to look out for regarding the fan. Time to pop the cases off again and do some preventative maintenance.

I finally got my 2nd MMM to program. I ended up reseting the parameters on my DX3R and the MMM found neutral. I'm still not sure why I didn't have this problem with my first MMM, but eveything's working fine now.

Thanks for all your input Patrick. It's great having your help in this forum! :smile:

The fan wires are being pinched between the circuit board and the plastic cicuit board stand offs built into the case bottom. If you trim the standoff down about 1mm it will no longer get pinched.

I've very glad to hear straight answers from Castle. How does this news affect the shipment of the "Second batch" which does not have this issue? Has that been delayed? I recall that there was supposed to be more shipping around mid June (that's only 1 week away.)

Please advise.

Like many guys here I'm waiting for a MMM for a project, if it appears that there is light at the end of a short tunnel, I'll wait. If not, I may just get another MM and roll the dice, my MM has been such a super product, I just hope the MMM can follow when the kinks are worked out.

The other thing about the stock fan is the plastic it's made out of is super brittle. I took the burned out fan out and was just gently squeezing it to see how flexible it was and it crumbled in my hand.

You sure it was not brittle from the heat/fire that occured?

Well, the fan in my MMM finally gave in. I also noticed that one blade on the fan broke off...possibly blocking the fan and burning it out. I'm not going to bother getting a replacement fan from Castle since it seems like these fans are about as durable as 3racing fans. I'll try the Novak fan and if that dies too I'm going to mod the case to fit a Muchmore fan. I've been running the Muchmore fans on my 4 MM's and have never had a failure.

On the plus side, I ran my MMM on 6s again today and it's still going strong. My Savage will easily backflip back onto it's wheels on pavement. :mdr: I tried to do some GPS speed runs, but my Savage is just too unstable over 50mph.

@pdelcast; don't know if you buy directly from the factory, but some brands have got copycats who copy their transistors/fetts. (without their permission..)

I buy directly from On Semiconductor for my FETs.

What kind of discounts are they giving you? Usually they offer Authorized Distis. and resellers some discounts so we can sell components to EMS, ODM and who ever assembles electronic products. Also, what do you do when there's a shortage or a long lead time on the item you use?