JBL 4430 - What Damage ?????

[Harry]

Looking for help trouble shooting........I use 2 Adcom GFA 565 300 w mono amps with these speakers.I was having a problem with one amp and apparently had it repaired(loose connection in the Power Supply) but when I got it back and hooked up it and switched it on...it made a bang as though a 357 magnum was fired in front of me.Sounded real bad,not to mention the fright I got.Anyway now there is no bass,some crackling sounds emenating from below but that electrical charge must have fried something.
Any help would be really appreciated.....Thanks in Advance....
Speakers bought new in 1989.

Cheers Harry.

[johnaec]

Have you swapped amps to determine if it's the speaker or the amp that's bad?

John

[Harry]

Hello John,one amp is definately ill - gotta go back to repair shop.The speaker is pretty sick as well.Yes the good amp is fine and one speaker is fine.What assistance I'm looking for is to determine if the Driver is kaput,Network kaput etc..

Cheers Harry

[John]

Wow If that happened to me I would be pissed off!!! Have you used this repair shop before???:banghead:

[johnaec]

I assume this means you've tried the good amp on the "bad" speaker and there's no low frequency output?

If so, I'd pull the questionable 15" out and check the resistance across the terminals. A short or open circuit will be a dead giveaway as to the speaker's health. Does the cone move freely in and out, or is it frozen in place?

If the speaker resistance and movement checks out, (I imagine between 6 and 8 ohms resistance), I'd next look at the crossover components.

John

[jandregg]

I would not try the bad amp on the other speaker. That could lead to two blown speakers. Use a meter first.

John

[scott fitlin]

I would not try the bad amp on the other speaker. That could lead to two blown speakers. Use a meter first.

JohnThis is correct. Whatever the problem is, your repaired amp blew up upon turn on, and took your speaker with it! DO NOT put it on your other speaker!

["Duke" Spinner]

i hope the repair "tech" soon hears of your displeasure ....

[johnaec]

I would not try the bad amp on the other speaker. That could lead to two blown speakers. Use a meter first.I was thinking more of the good amp on the "bad" speaker, but of course, that could lead to problems too, especially if the speaker coil is shorted! Definitely check resistance first. If it checks OK and the cone isn't frozen, I'd put it in the "good" cabinet to check it with the known good crossover and amp, and go from there.

John

[Mr. Widget]

When I first saw John's post I was concerned about blowing the second speaker too, but obviously what he meant was take the known good amp and apply it to the known bad speaker, and see what results. If the results indicate the lack of bass and "some crackling sounds" we know the speaker is damaged. Next, take the "bad" woofer and place it in the good cabinet hooked up to the "good" amp. If it plays correctly, we know the damage was to the network, if it continues to lack bass etc. we know the woofer is damaged. Next take the good woofer and place it in the damaged speaker. If it plays normally, we know that network is good, if it doesn't we know the network is damaged.

This should be pretty obvious, but if you haven't already done so, it will be revealing.

Widget

[Mr. Widget]

There's John now... I missed him by a minute...

[Harry]

The speaker is not frozen and moves freely will do the swaps tomorrow and get back to you, could not check resistance( no meter - will get tomorrow).Thank You all for your help so far .............Harry

[Harry]

Hello,doing the thanksgiving turkey eating at the in-laws today soooooo,do the swaps tomorrow,Just wanted to keep you in the know....

Cheers Harry

[Harry]

Morning All - well the damage is to the woofer it is not working.Can it be repaired or is a replacement 2235 purchase required????? Waiting for Guidiance..
Cheers Harry

[scott fitlin]

Good morning, Harry. Your 2235 can be reconed. Do you have a competent JBL authorized repair where you are?

Are you certain that whatever happened when your amp blew, it didnt fry anything in the crossover network as well? It did take out the woofer, it could have damaged something else as well.

If you do have an authorized JBL repair on Cape Breton Island, I might opt to let them look at the entire speaker. I know what I`m suggesting is a major PITA, but you need to check the xover network in the speaker that got damaged as well.

BTW, I went and googled Cape Breton Island, was looking at Baddeck, very nice place!

[Harry]

Hello Scott.I did the swaps as suggested and the speaker is alive with the good woofer, so I do not think it hurt the network as it sounds fine.Living in beautiful Cape Breton has it's drawbacks, ( I live about 30 km (20 miles) from Baddeck) I had to ship my amplifier 500 km(312 miles) to a high end audio shop in Halifax for them to repair ( well not yet - ha ha)They are going to fix it when I return it later in the week.Now as for a JBL outlet.... Soundcraft Canada is in Montreal Quebec 1200 km (750 miles) they are the JBL
representatives in Canada.
However I had my Infinity Kappa 9's reconed in Halifax and they did a great job so I could send the woofer there.Today is a holiday in Canada so i'll be on the phone in the morning ordering a recone kit..Will let you know how I do and if there is a problem acquiring a kit I'll post for help......
Thanks Everyone for the assissitance,Harry

[scott fitlin]

OK, since you know for sure the xover network is good, all you need to do is have the 2235 reconed.

Once you get it back, everything should be fine!

[johnaec]

...high end audio shop in Halifax for them to repair ( well not yet - ha ha)They are going to fix it when I return it later in the week.I hope you're going to try getting them to help pay for reconing the 2235. After all, it was just fine until the amp they "repaired" blew it up.

John

[scott fitlin]

I hope you're going to try getting them to help pay for reconing the 2235. After all, it was just fine until the amp they "repaired" blew it up.

JohnGetting them to admit they screwed up? Its worth a try though.

[Harry]

Hello Guys,may have gotten LUCKY and it is just the lead that was fried.Did a test with the JBL TECH (good amp - bad woofer,played music and pushed the woofer in and out and there is life in there will know for sure Saturday when the driver is on his bench.

["Duke" Spinner]

ya mean the Lead is fried, and that eensy teensy wire in the VC didn't Smmmoooke ???

[Harry]

Hello,just to update my problem my 2235H is reconed and will soon be back in the box.The amp on the other hand should soon be fixed,it turns out that the repair shop did not cause the speaker damage it was the amp itself.Adcom 565 amps develope a DC offset problem that will burn out a speaker or lead to a major failure of the output transistors.The electrolytic caps leak and cause corrosion.So anyhow thanks again for all the help...Cheers Harry

[John]

Do you not find it strange that all these fatal problems with your amp showed up the first time you fired it up upon returning home with it from the repair shop?:hmm:

Can I also assume that the same shop that did the repair work on the amp the first time around is giving you this latest story.:bs:

[MI-9448]

Have been on the planet over half a century and have run into this all through my life.Guys offer to repair stuff,realize they are in over their heads.Try anything to get it out of the shop and when it takes off like a skyrocket with a line cord they blame everything from you actually hooking it up, to"your line voltage is 120 vac? the amp is only rated for 117vac! See ....right here on the back!!This cynical attitude goes back to 1964 when an uncle gave me a nice Madison Fielding Tuner an Eico HF-85 and a home built stereo amp. I hooked every voice coil within twenty miles to it,all at the same time!! And had hours of fun with the set.One day what i have now deduced was a 6L6G failure led to some smoked resistors.I brought it to a schoolmates dad to repair(local TV guy).I couldn't go back to my Uncle Nick as that would be a lecture and a half! I started to do odd kid jobs to get the money.After about two weeks I had the 34.50 he wanted.I got it home and it stunk up the house.Still broken.The Uncle had it fixed in ten minutes.And yes the lecture was severe and ohms law was my assignment which i am expert at in every way to sunday!!The point is,Before you plunk down your dinnero,Tell them you want to see it work.If I had done the repair,The satified customer look makes it all worth while and for the next hour or so you feel like Grant did after taking Richmond!!