Synth Defects - Ticking Time Bombs

[rschnier]

All good points. Cheers!

[ppg_wavecomputer]

[...] The Polysix's battery type seemed to be among the worst for emitting the vapor, as luck would have it.

The PPG back-up batteries are quite as bad. They happen to be the same blue VARTA variety and cause quite as much damage.

Coincidence?

Stephen

[synthparts]

Brilliant analysis Dan. The synth community is lucky to have someone with your expertise, love of the instruments and and the willingness to share!

Heh, this is rather ironic coming from you since your response to my post about the dangers of old tantalum caps in the Help forum was to stop spreading "myths"...

Anyway I have posted many times in the Help forum about those old tantalums which usually fail short-circuit in lots of old synths. Among those are the Four-Voice, OB-X, OB-Xa, Prophet-5 (all revs), ARP 2600, Omni, Omni-2, Odyssey, Yamaha CS20M/40M, and even stuff like Eventide H3000s...

[max badwan]

In truth it often amazes me how reliable most music gear is but with most vintage synths now being 25+ years old frankly there is a potential ticking time bomb in every one of them - after all, how long would you expect the other electronic gear in your house/studio to operate without fault?

Yeah, I've still got a functional Atari ST, from '88 (or '89?) - but every single PC/Mac I've bought since then has died. Most of my gear I bought way back when, and in large part, still running. I've had an Emax SE die on me, and an Akai AX 73 - other than that, I've had good luck, but I was taught from a young age to respect and care for my instruments. I don't eat or drink near a keyboard, and I wash my hands before I play.

[cornutt]

Kawai K5/K5m/K5000 are notorious for the LCD backlights failing. Practically every on you see will have it failed unless someone has fixed it. And the display is pretty hard to read without it -- all those one-pixel modulation indicators. On most of them (was true on my K5m) both the EL backlight itself and the DC-DC converter that powers it were failed. It's fixable, but it takes some work. The display is held in by metal tabs that you have to bend in order to remove the display, and you can only do it so many times before the tabs start to fail from fatigue.

[ItsMeOnly]

Kawai K5/K5m/K5000

Any display with electroluminescent backlight does, that counts for most of synths from the 90's (Akai, Kurzweil, Korg, Roland and Yamaha and not limited to Kawai). And, to be honest, it doesn't affect the synthesizer performance - so hardly a bomb of any kind. And, BTW, DON'T remove the metal tabs - that was my mistake during first backlight change - aligning contacts back will take ages. Only a handful displays (never encountered any in a synth) would require disassembling this way. The EL foil slides in between contacts near PCB.

[rhino]

http://www.buchty.net/ensoniq/shop.html
Is now stocking his replacement mpu for the display of the Ensoniq ESQ1 and SQ-80.

These are modern chips programmed to emulate the 6500 processors that die and cause a blank, frozen or fubared display - also, since the chip is part of the serial loop from the keyboard to the mainboard, the synth often will go dead when this fails.

Cheers to this guy and his efforts! I've to five ESQ-1s waiting for this fix!!!

[Virgule]

The Peavey DPM line is prone to Ni-cad battery leakage issues. My V3 rack has not suffered any damage but doesn't retain patches anymore and I have to load them evey time I turn it on.

[seamonkey]

What a great thread, perhaps we could consider making it a sticky.

Korg Prophecy: the L/R output jacks. The output becomes intermittent over time and eventually will cut out completely.
I've had 3 of these over the years, and every one of them will either have this problem or develop it.
Korg must've had a design flaw for some years, because many of the same era synthesizers seem to also have this problem with the output jacks.
My Korg Wavestation has developed the same issue, and I remember reading some years ago the Korg 01/W series of synths also have this issue.
If buying a Korg synthesizer from this time period, the output jack issue is one I would be certain to ask the seller whether it has this problem or not.

Korg Wavestation: I can confirm the sticky key issue. I was brave enough to open up my Wavestation and apply a small amount of titanium lube to the bushings. Seems the bushings become dry and brittle. Also, the guide rod for the keys will become bent, causing a key to fall.
Mine is working fine since the lubrication(this was probably done a decade ago), but it took several tries, and I still have one key that isn't cooperating and stays fallen. I may eventually just buy a new guide rod for it if possible.

It's my understanding the high pitched whine is due to the inverter in the backlight assembly. Replacing the backlight will not fix the problem.
A great resource of all things Korg Wavestation is a site run by Dan Phillips. It has a fantastic FAQ section, instructions of the sticky key fix and some great links. http://www.danphillips.com/wavestation/ws_faq.htm

Emu Emulator III: a wonderful sampler but I believe most of them have ghosts in the machine.
Works fine one minute and the next you've got problems. You can often lose voices, the boards inside are sensitive to movement. There's a common joke amongst EIII owners, "don't move your Emulator III". Seriously, these seem so sensitive, if you touch them, something will go out of whack.
If you HAVE to have one, best to use Pick Up Only, because shipping will only guarantee problems. The boards become loose, the components on the boards will also loosen, and you're looking at opening it up and re-seating everything you can touch.

If you still want an Emulator sampler from the past, the EII is still a great option, built like a tank and oh... that classic sound that you don't hear anywhere else.

[gridsleep]

Ensoniq Fizmo, the regulators in the power supply c**p out.

And the original tactile switches in the 303/606 and V-Synth don't last very long.

You can say "c**p" in public. It's from someone's name. Thomas Crapper, who invented the modern ballcock flush toilet. No, I'm not making it up.

[cornutt]

The forum software automatically substitutes "c**p".

[fh991586]

You can say "c**p" in public. It's from someone's name. Thomas Crapper, who invented the modern ballcock flush toilet. No, I'm not making it up.

Please check your sources again.
http://theplumber.com/thomas-crapper-myth-reality/

[Tekhed66]

You can say "c**p" in public. It's from someone's name. Thomas Crapper, who invented the modern ballcock flush toilet. No, I'm not making it up.

Please check your sources again.
http://theplumber.com/thomas-crapper-myth-reality/

I think I prefer the myth...

As to synth defects (is this thread still active??), the trusty old JD-800 is prone to 'self-editing' if the 50+ slider pots aren't cared for ... dirt and general wear and tear can trip these sliders and completely mess up your patch depending on which parameter is triggered.

Replacement parts are extremely hard to find (Syntaur sometimes have them in stock but they're pricey) ... the best remedy is to clean them yourself ... depending on how bad they are it might mean de-soldering them from the board and dis-assembly before cleaning (been there - done that).

[Ncapone]

Anything vintage Crumar...

[cornutt]

- Roland Juno 106 / MKS-7 / MKS-30 / HS-60 - the voice chips have an epoxy coating that eventually short the chips resulting in dead voices.

Never saw it noted here, but the GR-700 also uses those.