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VZ 3500 is dead. :(

emily - 2008-04-01 13:31

I've been having issues with it for years. Noisy mode switches, which seem to get better the longer it's been on.
Sensitive volume switch - by the time you bump it to 2/10 it's UNBEARABLY loud. Who knows what'd happen if I put it up to 8 or 9.
Records play at the wrong speed. Like 5% fast. Not horrible but it makes the singers sound a little bit pitchy.

This last week was tragic. First, I noticed my right speaker had an issue. The base cone has cracked and a chunk of it fallen off.

And then...then...I was listening to an mp3 player through the AUX channel, turned only to about 1.5 volume, and suddenly there was a horrible loud earsplitting chest-thumping bass noise. The sort that knocks you off your feet. I dashed and hit the power button.

When I turned it back on the noise was gone. But after a minute or so of listening to the mp3 player the noise came back. The noise now arrives at increasingly short times after listening to anything. LPs, cassette, radio, AUX.


I'm very sad about it, I love this old machine, and it's cosmetically very pretty so I hate to see the guts having issues.

emily - 2008-04-01 13:32


The VZ in question.
Frown

fatdog - 2008-04-01 15:24

Does it make the noise without listening to the MP3 player?

emily - 2008-04-01 16:51

Yes, and the mp3 player is fine when using headphones. (It is plugged into the VZ via a 1/8" headphone-to-RCA cable.)

It makes the horrible noise no matter which mode is selected.

For example on "Phono" mode, I get 12 seconds of music, then a loud "POP!" (during which the little input level meters jump correspondingly) and then there is no sound, and the input meters show nothing.
The first time it happened it wasn't a pop, the noise just continued, and the meters stayed lit up until I hit the power button.

Also, the horrible noise *is* dependent on the volume level. Louder volume equals louder pop.

So I suppose there is a short somewhere in the machine. It occurs independent of mode, but it occurs before the "input level" meter, and before the volume, obviously.

arkay - 2008-04-01 19:17

Your box needs a little TLC. Boxes, like people, tend to develop little problems as they age. Fortunately, it is easier to rejuvenate a boombox than an aging body! LOL I would suggest you STOP USING IT, UNTIL IT IS FIXED. There is a real risk of burning out components like output transistors and even speakers, if you run it while it is making horrible loud noises.

Here is what you should do to make it sing sweetly and safely again:

FIRST, you need to clean all the controls (potentiometers like the volume control, balance control, etc... -that is, things that turn and have contact surfaces which can oxidize). The best thing to use for this is Caig's DeOxit, followed by Faderlube, also from Caig. You need to open up the box, and find those potentiometers. There will be a small hole in each one. Using the thin straw that comes with each spray can of DeOxit, squirt some inside the hole, then work the control back-and-forth a bunch of times (20 to 50). You may need to repeat this process if the oxidation is bad enough. Once it is clean, then spray the Faderlube inside. This should get rid of much of the problems you've been hearing over time.

SECOND: The irregular speed of the turntable is probably due to aged rubber drive belts (like big rubber bands). They will need replacement. The vertical VZ mechanism is a little awkward to deal with compared to most turntable arrangements, so you might need a service manual to do this correctly. The other possibility is that some lubricants have dried up and become thick or sticky, affecting the speed. If so, the old lubricant should be cleaned out (be careful that the solvent you use is safe around plastic!) and new lubricant added.

THIRD, you probably need to replace electrolytic capacitors inside, which by now have grown old and dry or leaky. This is a little too complex for me to go into here. It isn't difficult to learn to do, but if you don't know what a capacitor is, or don't know how to solder, then maybe find someone qualified to help. It's a good idea to check the resistors and replace any that are out of toleratnce, at the same time. You might also want to replace any aging/oxidizing trim pots at that time.

FOURTH, you may need to re-do some solder connections. Suck out the old solder using a soldering iron and a "solder sucker" or use desoldering braid (or both), then re-flow the connection properly with clean, new solder.

LASTLY, you MAY need to make other adjustments such as DC offset and bias, but you'll need a service manual to know where/how to do that.

You may not need to do all the steps above, to have your box working again. It might only need the first step, DeOxit, but from your description of the problems you are hearing, I suspect you'll need more of the steps. If you do everything I just described, your box will be functionally as-new, and should function for years more without trouble.

So not give up on that great old box. It IS repairable, for sure. If you can do it yourself, great. If not, find a tech who can. In either case, try to get the service manual first. It will save you a lot of hassle, and help you (or your tech) to fix it correctly. A good tech can fix it without one, but it is much easier to do things correctly, with the manual. GOOD LUCK with it!

emily - 2008-04-01 19:37

I have stopped using it! Smile I only turned it back on those few times so I could figure out better where the problem was occurring!

I probably won't fix it myself - I don't have the equipment and I DO have 2 toddler boys who would interrupt constantly. But I do have a dad who is versed in fixing electronic components. He fixes the PCBs in construction leveling lasers for a living and develops his own schematics.

I talked with my dad tonight and we'll just haul it out to him next time we visit. He has some ideas about where the problem is occurring. Well, and the other problems.

Thank you for the helpful tips, although he's experienced electronically he doesn't know the Sharp VZ boxes inside and out, so these will be handy. Smile

smokinendo - 2008-04-02 08:34

I recently found one of these with a few problems and fixed them all on my own. I'm not that great with electronics but I'm pretty mechanically inclined. I have more pics of how the box comes apart and I bought a manual from eBay. The manual hasn't arrived yet but when it does I'll scan every page and send you what's there. Maybe it will help, I'm not sure if the wiring schematic is in the sales manual ? Either way I would do what I could to get it working again as I sure you already know it's a nice loud powerful unit with great sound... it's a high end sharp

But it you decide to part ways with it I'll buy the speakers Big Grin Just kidding I would fix it and keep it

MyVZ3500

emily - 2008-04-02 09:36

I actually have the original user manual - I'm only the 2nd owner it's had. They are great-sounding machines, aren't they?

You don't want my speakers though, one cone's cracked and bits have fallen off.

We are going to do our best at fixing it. I definitely don't want to part with it.

smokinendo - 2008-04-02 09:45

quote:
I definitely don't want to part with it


LOL I sure... I love that thing, when I finally got everything working on it I was so excited. I hope you end up working it out and have her back up and running smoothly

Good Luck
Brian