9920 damage need fixin - RC-Monster Forums

steveo · **9920 damage need fixin -** 07.10.2006, 05:25 PM

hey guys do know if mike does repairs on speedo my caps got damaged in a crash and it the feels lazy and, no good speed

thanks

squeeforever · 07.10.2006, 05:34 PM

Yea, shoot him a e-mail and see what he says.

brijar · 07.11.2006, 07:15 PM

Yeah, I've got a 9920 that the red programming jumper's mount has broken off. I tried soldering a couple of wires onto the circuit board where the jumper mounted, but as I don't have a very steady hand, it was rather weak and just broke off again. Then I tried soldering it on there, then putting 5 min epoxy over the joints to secure them, but now it has come off again. I sanded down the epoxy on the board to expose the spots again, but I'm not sure what to do right now. I definately can't afford a new ESC, and I don't really want to send it in to get it fixed. Is there any way to fix this that works good?

Thanx,
Brijar!!!

BrianG · 07.11.2006, 07:59 PM

Well, you can do this three ways; the right way, the quick way, and the proper way. The proper way would be to send it in. The quick way would be to simply bridge the two spots with solder (since that what the jumper does), but then you'll have to unsolder it again to program the ESC. The right way would be to remove the solder from the holes with a heated solder sucker (uses a vacuum to pull the solder out as it is molten) or solder wick to remove the solder from the holes, and then re-solder the jumper into the holes where it belongs.

go4gold · 08:41 PM

You forgot the easy way. Send it back to get repaired, probably even with some sort of warranty. It sounds like your solder skills are not the best. I would send it back before ruining the board trying to fix it. Better down a couple of weeks than to be down 1 week and out 150-200 dollars. Good luck.

BrianG · 07.11.2006, 09:28 PM

Quote:

Originally Posted by go4gold

You forgot the easy way. Send it back to get repaired, probably even with some sort of warranty.

Actually, that was the first option in my post. He has already tried to solder it so a little more won't do any harm as long as he doesn't overheat the board. What probably happened is the holes for the pins still has solder in it and he tried to solder to the top of them, which isn't very strong. If soldering is too difficult, I would suggest having someone who has the proper tools do it. Or, to be safe, send it back.

squeeforever · 10:28 PM

Actuallly, on the 9920, there arent holes. Its just a spot and the are soldered on very lightly. they would be alot stronger if there were holes. I would know, I've broke 2 off :mad:. Luckily I was able to solder them back on. Its not really that hard, I just dabbed a little solder on the board (since theres almost none from the factory) and placed them both on there at the same time while in the jumper and touched it with the soldering iron, and presto! Done...

BrianG · 07.11.2006, 10:29 PM

Wow, that sucks. Sounds like it will probably happen again then no matter what you do. Well, in that case, you could program it the way you want and then just solder across the two solder pads. If the gap is a little too wide, use a very short piece of wire to bridge it. You'll have to desolder them again if you ever need to re-program it though...

brijar · 07.12.2006, 11:58 AM

Well, I got un-lazy and tried to solder the right way. I tinned the spots on the circuit board and tinned the wires. Then I put the tinned wire on one of the tinned spots, and put my iron to it, and it went right on. I did that to the other one and just stripped the non soldered ends of the wires and twisted them together. It seems to be working great, but when I'm driving it around in my Rustler with 1 7-cell GP3300 battery because my Maxx is down right now, the truck will be going full throttle and just stop for about 1 second, then go again. It is very annoying, especially when you are trying to climb a 60* loose dirt hill with RWD and on-road tires:035:. I think this is cogging, but I'm not sure. I tried putting in a fresh pack, but it did it even worse. I'm charging my RX pack right now, so maybe that will cure it. It has never done this before in my Maxx or when I had it in my Rustler.

Thanx for the help,
Brijar!!!

BrianG · 07.12.2006, 12:13 PM

Good job on the soldering. The only problem with simply twisting the wires is that you'll get oxidation on the exposed wires and the contact will become poor. Also, the vibration may momentarily break contact in the twist causing some weird stuff to happen.

Cogging usually only happens at very low speeds because the ESC can't sense the motor position so it turns and stops turning in rapid succession.

brijar · 07.12.2006, 12:31 PM

Well, I stripped them about 1/2 and inch and twisted them all the way up very tightly. After my Rx pack is done charging, I will see if the glitching goes away. I have noticed that if a battery wire touches the antenna tube, or gets withing 1/2 inch of it, then there is bad glitching, so I have made sure that there is nothing touching the antenna tube except the antenna wire. Speaking of antenna, my old one was just recently ripped out of my Traxxas 3-Channel Receiver when I plowed into a 3-rail fence in midair:032:, so I replaced it with 27 inches of Futaba Rx wire. I'm not sure this is causing the glitching as I replaced the wire in the same fashion on my other Traxxas Receiver and it does not glitch. Thought you ought to know in-case that is causing something.
I'm glad I used my 40w iron instead of my 80w iron:036: :007: :032: on that circuit board.
BTW, that was a really quick reply:027:! After I posted, I edited my sig for about 5 minutes and bam, there you are! Thanks a lot!

Brijar!!!

brijar · 07.12.2006, 12:58 PM

Well, that seems to have done it. After charging the Rx pack it only glitched once for the rest of the run. My Duratrax Digital piranha said it put in about 600mah. My Rx pack is 1100mah, so it was pretty empty.

Thanx a lot for the help guys,
Brijar!!!