HELP PLEASE! zx475ti rf channel/comes and goes out

thedeal7235 · Post by **thedeal7235** » Mon Sep 20, 2010 7:14 pm

Any help or suggestions would be great guys- My zx475ti is set up to my front tweets/multiplier switch pushed in/tweets crossed @ 4khz/-a few months ago i noticed the rf tweet not playing, i go and pull dmm out and the tweet starts playing again-(ive checked resistance and the tweets fine-i even put my mids on the 2 front channels and after a short period the music on that channel goes out(same as it did on tweet T DIFF.FREQuency)/then comes back in/ i was hoping i had a bad rca, as i even ran the rear channel, to see if it would reproduce the coming/going of music, and it never happened-any clues where to start? if my rf output transistor is going bad, wouldnt it just go bad, or could the music come and go? thanx in advance

Post by **ttocs** » Mon Sep 20, 2010 7:25 pm

at this point you do not know if it is the amp or the speaker correct? Swap the rca's to on that channel and see if the problem moves to the other tweet or if it stays there and then we can figure out which way to go.

thedeal7235 · Post by **thedeal7235** » Mon Sep 20, 2010 7:30 pm

thanx ttocs, but its the amp-i disconnected the tweets for 2 weeks, ran the mids on the front @ different freq. and it still occured-when i ran the mids on the rear channel(same set of rcas) it never happened, even to this day, so im afraid its the a part in the amp i may not be capable of fixing(and its frustrating, cux the amp sounds sooo clean)

Post by **ttocs** » Mon Sep 20, 2010 7:34 pm

now do you know if its the signal fed into the amp, or just the amp itself? Have you tried a different audio source and found the same results?

valeks1 · Post by **valeks1** » Mon Sep 20, 2010 9:56 pm

Front CONFIG switch is bad? Some times you can fix it by clean it with contact cleaner.

dwnrodeo · Post by **dwnrodeo** » Tue Sep 21, 2010 3:21 am

valeks1 wrote:Front CONFIG switch is bad? Some times you can fix it by clean it with contact cleaner.

Yep. Most of the time the crossover pots, gain pots, or config switch gets dirty. Very common with this amp. I'm betting this is your issue.

thedeal7235 · Post by **thedeal7235** » Tue Sep 21, 2010 5:19 pm

thanx guys, it occurs w/different sources-i had a chance to switch amps out for a couple days, and im afraid it never occured(music coming/going on rf channel)-im starting to also think its the xover-in theory, if i bypass the internal xover, and slap on the passive xover for the tweets, the tweets should be protected, correct? im hoping if i do this i can narrow down if it is the internal xover, pots etc., or the front rca inputs???

eulogious · Post by **eulogious** » Wed Sep 22, 2010 5:32 am

valeks1 wrote:Front CONFIG switch is bad? Some times you can fix it by clean it with contact cleaner.

Would this cause this issue? I have thought I have heard the same thing out of my zx450, with mine the left front is going out, but thought I might be losing my mind because I could never really nail it down as to what was going on. But I do know that it is not the speaker or my RCA's, because I have replace both of them and I still have the problem. But I have not heard it for the last few weeks... but have since replacing the speaker and RCA's. I might have to clean that switch out if it happens again.

dwnrodeo · Post by **dwnrodeo** » Wed Sep 22, 2010 7:36 am

thedeal7235 wrote:thanx guys, it occurs w/different sources-i had a chance to switch amps out for a couple days, and im afraid it never occured(music coming/going on rf channel)-im starting to also think its the xover-in theory, if i bypass the internal xover, and slap on the passive xover for the tweets, the tweets should be protected, correct? im hoping if i do this i can narrow down if it is the internal xover, pots etc., or the front rca inputs???

Just do what Valeks1 said. Spray some contact cleaner and turn the pots back and forth.

longboard · Post by **longboard** » Wed Sep 22, 2010 10:23 am

whats the best contact cleaner to use any one have a good one??

Post by **ttocs** » Wed Sep 22, 2010 11:03 am

go to radio shack and they have some stuff there made just for it, comes with a straw on the tip and everything.

longboard · Post by **longboard** » Wed Sep 22, 2010 11:11 am

yeah just did a search on rs because i have a account but they list 665 diferent types lol!!

dwnrodeo · Post by **dwnrodeo** » Wed Sep 22, 2010 11:16 am

I've used DeoxIT Gold with success before.

Post by **ttocs** » Wed Sep 22, 2010 11:37 am

funny i have never seen that much variety there in person...

thedeal7235 · Post by **thedeal7235** » Tue Nov 09, 2010 5:09 pm

ive been trying to find the active ingredent in these contact cleaners-does anybody know a reg. household item that may do the same trick? thanx in advance

Post by **ttocs** » Tue Nov 09, 2010 5:54 pm

tried alcahol or nail polish remover?

thedeal7235 · Post by **thedeal7235** » Tue Nov 09, 2010 6:00 pm

not yet, but I HAVE THOSE!!!!!!!!!!!!!! i beleive the problem is the front xover knob in hp w/multiplier switch- i remember a few years ago i spoke to a russian gentleman at portland pg, and he commented the pot builds up resistance in it, thus causing an audible squeal, very annoying in hp-ill unhook the amp now and take the cover off, and gently clean the pots, look for oxidation on the xover board-with alchol , or np remover, what type of device to use? dont want to use a q-tip

Post by **ttocs** » Tue Nov 09, 2010 6:06 pm

pots can often develop some resistance by the way they work. Alot of pots are self cleaning, so if you swipe them back and forth 10-15 times and it will clean it up for some time as the wiper will clean the terminal as it goes over it.

thedeal7235 · Post by **thedeal7235** » Tue Nov 09, 2010 6:11 pm

ive turned them back/fourth several times-goes away for a brief period, then comes back-ttocs, do u think its even worth me taking the amp out to try, or just keep running it in bypass, sending the signals from my mx3i to the amp? i think it sounds "brighter, and clearer" using the onboard xovers

Post by **ttocs** » Tue Nov 09, 2010 6:13 pm

that is a tough call as I have neve done an a-b comparison, but if you have and have a preference and its in yer car they you are the expert.

thedeal7235 · Post by **thedeal7235** » Tue Nov 09, 2010 6:21 pm

mayb my verbage is off, it has more output, and it all blends better, with the roll offs from bp-lowpass, as i use the aux out on the 475 ti to the 600.2, bypassing its internal xover -mx3i is excellent, however it is older, and something internally is wrong with it, as when i do use it, the levels are never accurately matched on the front stage, even with dmm/sine wave gain setting-cleans the sub up, however, i like a little "harshness" at times on the low end, thats why i use my lpl;)

Post by **ttocs** » Tue Nov 09, 2010 6:25 pm

I am not sure how you would use a DMM to tune componants that you are running active. You would need to use afew different frequencies in order to match it half way accuratly and this would be the time that a scope is needed to tune it. If you just use the 1khz sine wave that is always recomended it will not go through the cross overs as well.

Wanna borrow my scope? its pocket sized and Small enough to mail......

thedeal7235 · Post by **thedeal7235** » Tue Nov 09, 2010 6:30 pm

hahahaha-thanx, but the dmm sine wave test tone, for me, works great-i never use the 1khz, as i always keep tweet levels low-imainly use the 60hz for the midabss and sub-i cant even begin to count how many pairs of tweets ive fried, not paying attention-LOL-mayb my ti xover, has just had its day??! which would suck, as i truly enjoy the front end on the ti