Two Home Theater Receivers - Same make & model - blow center channels!!

WHAT THE ?

This is JVC's RX-515V Pro Logic Surround Receiver, 80W mains, 20W Center, 20W Surrounds. 1994 model I believe.

The first one, I bought in 1995 new, blew center channel last summer. I plugged the center speaker into a mains output to check it - got sound. Pressed Test, got noise in all speakers exc center.

I was lucky to EBay a replacement from Texas, and it served me well until just today. All other speakers, features work. Just no center.

I do not know if the problem is on the internal input side of the surround, or the output side. I would appreciate some help fixing this as I really like the features and extra inputs these older units have compared to today's.

Why does the same thing keep quitting on this model?

Reply to
thekmanrocks
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Same central speaker with some intermittent short on the VC ?

Reply to
N_Cook

NCook mibht be right about the speaker, OR maybe it is four ohms ? Newer st uff (you call that vintage but I don't) really don't like pfour ohm speaker s.

Could also just be a weak point in the design.

Closest print I could get was for a 518 which may or may not be the same. I t shos discrete component output stages but the scan is so shitty I can't t ell much else about it. But at least it doesn't use ICs that you might not be able to get. Just got through with onr like that I had to slightly redes ign for a guy in Pittsburg. Damn shame all the money he has into that unit but he figured it was worth it. Redesigning is not cheap.

But IF it is discrete component it is just a matter of a few transistors, m aybe resistors. While I don't call that model vintage, it is probably worth fixing.

Or you could just take some eight ohm resistors from right and left and fee d the center from them. That is almost what the amp does in most normal mod es, but it does it at line level. Phantom and some other modes don't, but I don't know about you, I think L+R should be sent to the center channel. Th at way you might be abl to understand the dialogue in a movie amidst all th e %^#$$# special effects. It would work for now whilst you get one of them fixed.

Reply to
jurb6006

Nope. All speakers are 8ohm. Receiver calls for 8~16ohm loads, that's what I give it.

Additionally, all my inputs are padded

6 & 12dB via Harrison Labs attenuators. So both on the input and output sides both of my RX- 515Vs have been very pampered. :)
Reply to
thekmanrocks

In that case, see if you can find the layout of the thing to get near where you need to be and inspect the PC board fro bad connectuions. The wway the heat flowsa in these things can do nasty things to solder joints.

And the fact that it is not goiung into protection means it may well be just bad connections. When things short out, it usually won't kick the relay in or maybe blows fuses. I rarely say this - but it might be something simple.

Reply to
jurb6006

jurb:

Thanks for the vote of confidence. I really don't know my way around inside a receiver. Lots of tiny electronic components on a PC board. I can get near the white thing on the back-side of the center channel speaker terminals, but to solder I'd need to remove two or three vertical standing PC boards to get at the mother board, so to speak.

Rather just do the EBay thing again, and hope I get lucky.

Reply to
thekmanrocks

Update: Center channel worked briefly this morning, then a half hour later it was out again.

Definitely a loose circuit somewhere inside.

Reply to
thekmanrocks

See if you can see any small black plastic rectangles on the amp or speaker terminal board (relays). Tap on them with a plastic or wood stick. If the center channel comes back, replace the relay or resolder the connections to it if they look bad.

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Reply to
Chuck

I've worked on analog receivers almost every day for 33 years. While I cannot diagnose via usenet, if there IS a history of these blowing the center channel, I would look very closely at solder connections relating to the bias transistor. This is the type of thing that might cause such a history on a given model type.

The advice given on the relay is good if the channel volume is merely down or especially if the volume is intermittent and comes back with an increase of the volume control setting or as he said with tapping the relay body.

Mark Z.

Reply to
Mark Zacharias

Alright, Mark Z, et al:

I've discovered that I can get center channel - for a while - by moving the speaker wire around in the center ch connector on the receiver. Last night I stripped off an extra long length of wire, so as to bend it over to double the thickness.

That worked - last night. This morning I turned it back on, and got center for about ten minutes before it cut out again. I fiddled with it some more, and discovered that by having the speaker wire(16AWG by the way) *barely in* the connecting terminal, with the locking tab left up, I get center pretty consistently. If I pushed the positive in all the way - NO center. If I jiggled it - intermittent center. So we'll see how long it produces center with the positive barely hanging in there. Different times of day, the center works, other times, not.

My original RX-515, which is still in my cellar, is definitely blown center, at the component level. No amount of jiggling or doubling over the copper strands is gonna pass sound through the center speaker with that thing.

And the sad part of all this is JVC is OUT of the home audio business! Here they had a great mid-price surround-sound receiver for mid-1990s, ample power, connections for TWO tape loops(great because I have an EQ on one and my tape deck on another), and a phono input.

I couldn't give two s**ts about HDMI inputs, bluetooth, and X.1 digital surround if I can't hook all of my analog gear up to it!!

So I'm going to buy every remaining RX-515V out there, at least just for parts interchangeability.

Reply to
thekmanrocks

Depressing discovery:

These particular JVC receivers have PC boards arranged in a specific way: main "mother" board at the bottom, with two input boards angled 90deg. to it - vertical.

On the larger of the two vertical PC boards are most of the inputs: Tape 1, VCR in/out, CD, Video, & Phono. This larger vertical board interfaces the main board via two multi-pin connections(20-30?) pins each.

It is when gently moving this board side to side or up/ down, that I can cause the center channel to cut out in surround mode. In regular stereo mode, moving that input board has no effect aside from minor crackling.

This model receiver is just over 20 years old, and my examples of it are showing its age. Unfortunate, as I have no need for the features of modern receivers if ya cain't even hook up a phono or a cassette deck to 'em!

What I might end up doing is using the old JVC for all my analog sources, then Tape1 out to the "PC" or DVD input on a new digital 7.1 receiver. My TV and DVD player can just HDMI out to that modern unit, and when I want to listen to CD, cassette, 8-track, or records, i just select that input on the old JVC, and the remaining analog audio input on the modern receiver.

Reply to
thekmanrocks

Just got my third JVC RX-515V in the mail today - fully functional, but with same problem:

The smaller PC board perpendicular to the mother board connection has eroded over

21 years. Out of the box, no center channel in pro-logic mode. After some wiggle and tapping, it worked.

So what I will do is use this RX Receiver as a stereo only for all my analogs, and feed tape

1 out to a modern digital X.1 surround receiver with pro-logic for surround from 2-ch sources.
Reply to
thekmanrocks

Where are you geographically ? Maybe you should just bring the thing over (Ohio) with some money and some beer.

If I fix one here, you'll probably know how to fix the other two, unless you smoked the original one.

But really, in text this is worse than trying to do it over the phone unless you are with some seriously good people with tech and communicationg by whatever means.

I am different than alot of techs, I WILL let you watch.

It's the talking that can costya.

Reply to
jurb6006

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