Think I have a big problem

Blad09 · Post by **Blad09** » Sun Mar 25, 2012 4:14 pm

So I gave my zx350 to a buddy to swap out the caps for me. He got it opened up and all the old caps off just to find that the cap that exploded blew a hole right through the board.

It's about an 1/8" in diameter and to me, looks irrepairable. My camera isn't with me right now but I will get pics up, I just wanna know if this kind of thing is fixable, or if anyone else has had this problem. It pretty much blew the little gold square clean off the board. Please Help

Post by **kg1961** » Sun Mar 25, 2012 4:46 pm

there a guy selling a damaged 350 for 20 you could alway repair the board that way
alot of time eric d and other have fixed the holes but it cost more than the units are worth

Post by **smgreen20** » Mon Mar 26, 2012 8:43 am

I don't know if Eric would be up to it, but he's fixed a ZX450 board with a hole the size of a golf ball. So, Yea it can be done but take note, Eric is no amateur at it.

Blad09 · Post by **Blad09** » Mon Mar 26, 2012 12:23 pm

Well.... I'm tryin to avoid spending any more $$$ on stereo equip. so I was gonna give this a go myself. I just need to find my camera and get some decent pics up, that way someone may be able to guide me through the repair, if it's even possible. So in the mean time I will search for my cam and get those pics goin.

Blad09 · Post by **Blad09** » Tue Mar 27, 2012 12:53 pm

I know their bad pics but I think u can see the damage. Let me know what your thinkin.... anyone lol

Post by **ttocs** » Tue Mar 27, 2012 12:55 pm

doesn't look too bad although it is hard to tell.

Blad09 · Post by **Blad09** » Tue Mar 27, 2012 12:59 pm

I'm just rushing rite now. I'll try to get better ones up, I just thought these would at least give an idea what I'm dealing with.

Virtue · Post by **Virtue** » Wed Mar 28, 2012 12:38 pm

I blew up my M50 and put a hole the size of a nickle. I put masking tape on one side and used epoxy glue on the other side. Then I used a small drill bit to make holes for the parts and then ran small, solid wire for jumper wires. It has been working ever since. It does not look to bad either.

Blad09 · Post by **Blad09** » Wed Mar 28, 2012 4:54 pm

That's the kind of answer I was hoping for

I don't care what it looks like as long as it is SAFE and doesn't effect the performance of the amp. I'll still get some better pics up just so we can actually see the details of the damage, but I'll keep that method in mind. TBH, I don't have a f@#$ing clue how an amplifier actually works and I just don't want to solder in a short or somethin stupid so I'll wait till I have more detailed pics up and get some more advice. Thanks! Hopefully pictures up by Friday.

00goobs · Post by **00goobs** » Thu Mar 29, 2012 5:29 am

It looks like that hole is on the positive side of the cap. It also seems like it is soldered to the bottom of the board. So, you could actually solder the lead of the cap to the bottom side of the board trying to avoid getting solder in the blown up hole where it would short to the top side...

Like get a capacitor with longer leads and lay the lead on the back side of the board while centered in the hole...

Blad09 · Post by **Blad09** » Thu Mar 29, 2012 8:28 am

I'm really sorry guys, I can't get good pictures for the life of me. These are the best I can come up with. If you can't make a good judgement from these pics I 100% understand. Anyways, I think I'm going to do the epoxy thing to fill the hole and try to isolate the lead on that cap. Then I do think it can be soldered to the bottom of the board without the need of a jumper. Also, the circular pad that's beside the damaged square is ripped off the board as well ( is that the via's we're supposed to be careful with?) I think my chum did it when removing that cap and didn't want to tell me. So for that one could I just follow the tutorial from the How To? I appreciate everyones help and suggestions and, again, if it's too hard to give an opinion cuz of my pics, that's fine too.

Post by **ttocs** » Thu Mar 29, 2012 8:57 am

seen alot worse then that repaired...... ALOT worse.

Post by **Eric D** » Thu Mar 29, 2012 10:02 am

The bad area will need to be ground out. Burnt fiberglass board contains enough carbon to be conductive. If you don't grind away the burned areas, it will cause problems down the road (like a dead car battery for example).

Blad09 · Post by **Blad09** » Thu Mar 29, 2012 10:16 am

Eric D wrote:The bad area will need to be ground out. Burnt fiberglass board contains enough carbon to be conductive. If you don't grind away the burned areas, it will cause problems down the road (like a dead car battery for example).

I will make sure the char is gone before epoxy goes in. Thank you, I wouldn't have known.

Blad09 · Post by **Blad09** » Thu Mar 29, 2012 3:55 pm

OK, I filed the hole until all the burnt fibre was gone and went ahead and filled it with epoxy. Just need to wait 8hrs for it to harden so I can drill a hole for the cap lead. All I need to know now is... how to get the proper polarity on the new caps. From searching I've come up with:
long leg on cap> positive> square pad on board
short leg on cap> negative> circle pad on board.
Can someone just confirm this for me? Also, if there's a way to test my cap job before powering it, that would help me too. I would think a continuity test would do it, but I don't know. Thanks alot.

Post by **Eric D** » Fri Mar 30, 2012 7:56 am

There are positive indicators printed on the board. And yes, the square pad is positive.

Blad09 · Post by **Blad09** » Fri Mar 30, 2012 11:51 am

It's not as much the board that I'm not sure of, as it is labeled, I'm just not sure about the caps. Long lead is pos or neg?

Post by **ttocs** » Fri Mar 30, 2012 12:39 pm

you see the pointed stripe that goes down the side with the neg symbol on it? Thats the neg.

Blad09 · Post by **Blad09** » Fri Mar 30, 2012 12:44 pm

LMAO, okay thanks dude. I'll update when it's all done and hopefully working.

Post by **ttocs** » Fri Mar 30, 2012 1:03 pm

they need to make it just that easy for us techs(COUGH ENGINEER) or else everyone would be confused.

Blad09 · Post by **Blad09** » Fri Mar 30, 2012 6:00 pm

OK, all the new caps are in. Didn't turn out too bad. The problem cap isn't the prettiest, but I think it's good to go. Gonna try and put power to it tomorrow and see what happens. Thanks to everyone for their input, couldn't have done it without this forum. Let's hope for the best!

00goobs · Post by **00goobs** » Fri Mar 30, 2012 6:16 pm

I think if you have a volt/multi meter, you could do a diode test across the leads of the capacitor. It should only conduct (beep) one way when you test in correct polarity and reverse polarity. It is easy to do this test before you hook the batt up to the amp...

Blad09 · Post by **Blad09** » Fri Mar 30, 2012 6:30 pm

K. Is that just to make sure I've got good contact from top of board to bottom?

00goobs · Post by **00goobs** » Fri Mar 30, 2012 6:42 pm

For the most part, to be sure there is no contact between the top and bottom layers. It won't hurt to check. Also, you'll know if any fets are shorted or diodes are shorted too...

Blad09 · Post by **Blad09** » Fri Mar 30, 2012 7:12 pm

Alright, will do. Thank you.