DX7IIfd won't do anything

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evildragon
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Post by evildragon » Mon Jun 18, 2007 12:43 pm

DX wrote:mm it sounds like a OS chip problem or similar.

87.04 is the YY MM, so your keyb is from april, 1987.

Now I remember mine says 86.12
yea, that's what i feared.. i noticed too that if i let it sit off for long enough, the DX7 seems to work fine sometimes, till it warms up (minus the lacking floppy disk feature)

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Post by Maschinengeist » Mon Jun 18, 2007 2:24 pm

The hissing can be resulting of a faulty IC. But I wouldn't be surprised at all if some vital capacitors are about to die.

If you want one of my techs to look at your DX7, please let me know. I've got 2 techs in USA (Utah & Michigan) and obviously in Canada (Quebec).
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Post by evildragon » Mon Jun 18, 2007 4:43 pm

Maschinengeist wrote:The hissing can be resulting of a faulty IC. But I wouldn't be surprised at all if some vital capacitors are about to die.

If you want one of my techs to look at your DX7, please let me know. I've got 2 techs in USA (Utah & Michigan) and obviously in Canada (Quebec).
the hiss isn't actually a bad hiss, it's VERY quiet, i have to be looking for it, and have the volume all the way up with an amp.. i was using that expression that the audio is on...

I'm in Florida, and don't live near any of those areas, and won't be able to ship it (i used up all my money to buy the thing)

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Post by evildragon » Mon Jun 18, 2007 6:47 pm

UPDATE: This is totally weird.. I was just playing my DX7 live in the music studio for like an hour, and it didn't once suffer any of the above problems (still, minus the disk drive), and I was totally freaked by it.. As of this moment, I have put it back in it's case, but I swear that was cool..

Btw, when I load a voice in single mode, and I supposed to have to push the voice button twice? If I hit it once, I hear just small pops instead of sound... Hit the voice a second time, and they load fine...

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Post by DX » Mon Jun 18, 2007 11:46 pm

mm, I keep on the idea that OS chip could be wrong (perhaps a corrupted os).

Perhaps some wire or socket are giving you errors, considering you have found the Aftertouch socked pulled out
.

I noticed Mainboard has some thin wires soldered (mine is original, not E! or supermax). Check if any wire is loose on the mainboard (The one you see with the MIDI connectors and audio outs).

If not, always can drop it to maschine techs for giving an eye into it.
Roland Promars, E-mu EMAX and some other machines...

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Post by evildragon » Tue Jun 19, 2007 12:12 am

DX wrote:mm, I keep on the idea that OS chip could be wrong (perhaps a corrupted os).

Perhaps some wire or socket are giving you errors, considering you have found the Aftertouch socked pulled out
.

I noticed Mainboard has some thin wires soldered (mine is original, not E! or supermax). Check if any wire is loose on the mainboard (The one you see with the MIDI connectors and audio outs).

If not, always can drop it to maschine techs for giving an eye into it.
i will have to check that out later, i have the DX7 packed up for a recording soon... (i have the voice I want selected already, and the system "cooled down", so it'll work for my recording session)...

though, just curious, if the OS ROM is corrupt, why would the problem only happen after the system has been warmed up? I understand the corruption for the floppy drive button not even responding, but the warming up bit is weird..

i'll also get an in-circuit capacitor tester, and hopefully find a failing electrolytic, which I feel could be causing the problem..

(if the DX7 does any weird "sounds" while recording later, i'll record them with my laptop so you can hear the audio symptoms)

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DX7IIFD no work

Post by dachsis » Tue Jun 19, 2007 6:51 am

Couple questions, sorry,got here late...(1) when you replaced the battery, I did not hear you say you had to move the E! circuit board which will cover part of the battery. The E! board is very well marked, Now if you did not have to move E! board and set it aside teathered to 5 colored small wires, E! is not there. Was it supposed to be E! equipped? If so maybe someone removed it and did not reinstall the IC chip where the E! board plugs into the main circuit brd. Your DX7IIFD will never work without E! and without the IC chip. Must find a chip and reinstall it after removing E! (on a DX7 you remove 2 chips , #14 and #21 and the E! board plugs directly into the tractor slots of the IC21 & IC14) However, a DX7IIFD E! board connects to the DX via the use of a flat cable to plug into one IC slot only and 5 wires off J2 on the E! brd are soldered onto certain terminals on the DX brd. I am wondering, IF it HAD E! removed ?
(2) Forget E! if it never had it in or does have it in now but HAS ALL ICs for these two following Questions,,,a DX 7 or DX7IIFD IIFD will play a CRT with a dead synth battery as it does not depend upon memory retrieval,,,that is if the ROM CRT has patches on it still & is totally operatable and has not been unplugged for months..
(3) when you attempted to reload via the ROM CRT, did you disable write protection on both CRT and MEM before hitting LOAD?
Like a blankety blank computer fix some times, what wonders turning a DX 7 series machine OFF and ON a few times will do!!! Or leave the bloody thing ON overnight. Of the 12 I have IN ever-changing SETUPS, (I have 56DXers) I leave them plugged in 24 hours but not turned ON.

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Post by evildragon » Tue Jun 19, 2007 10:15 am

from what i see, it never had an E! card.. at first, it wouldn't even play sounds from the cart, nothing was ever produced, it only had occasional sustaining notes, or notes that cut short.. after i connected it to my IBM XT to play a midi file, things came "alive", as if it hit a register in the DX7's memory that helped a bit..

i have disabled memory protection, and have loaded the ROM sounds into the internal memory, and the behavior is the same, but it does keep the sounds in memory now.. i have even downloaded DX7 sysex files over the internet, and used a midi cable and put them in memory and it worked...

the inability to access the floppy drive menu is still making me ponder about it's ROM BIOS though.. why would the button not work, but work for changing voices? What did that button do on the DX7 II's without a floppy? I'm wondering if the ROM was perhaps replaced at one time with the wrong one. Also, if not, do the DX7 II D's, the ones without a floppy drive, do their motherboards have a floppy controller at all? (Same motherboard, different BIOS)

the floppy drive in my DX7 has the same full height 3.5" formfacter as my IBM XTs floppy drive, but has pins of a modern PC floppy drive.. i wonder if using a different drive is possible..

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Post by Analog Freak » Tue Jun 19, 2007 10:19 am

You own 56 DX series units? Holy c**p! I don't think I have a problem with collecting too many synthesizers anymore.
"All Your Synthesizers Are Belong To Us!" Literally.

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Post by evildragon » Tue Jun 19, 2007 10:25 am

yea, that's a lot :o

anyways, when my DX7 is first powered on, and i can hear the sounds normally, i still seem to have to push voice button twice.. it registers the first push, but i hear nothing but little "pops", or no pops at all, and when i push it a second time, it works... very erratic behavior..

EDIT: This is a sound recording of my II FD unit. I powered it up yesterday morning, and left it in dual mode with these two sounds running.. played the song in the afternoon, and it still sounded good like this.. but as SOON as I change a voice, all the oscillators go crazy.. (and it seems the LFO goes out of wack too..) Remember, if I had just powered this up, I could change voices fine within the first 10 minutes of powering it up (but still having to double-hit the voice button)..

http://blackevilweredragon.spymac.com/snatchersong.mp3

(the crackling from the recording is because i recorded it via my laptops MIC jack)

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Post by DX » Tue Jun 19, 2007 6:14 pm

That demo shows your DX working fine.
Can you post some demo when the weird sounds come up?

It is clear that something that affects OS (or the OS itself) are bad. So when a temperature is reached by some component, it starts to fail.

If you have several DX7 II, you could try to replace main board at first. If not, maybe the Power supply has to do with this problem due to possible voltage problem at high temperature.
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Post by evildragon » Tue Jun 19, 2007 7:09 pm

this is my one and only DX7..

everytime the problem crept up, i had no recording equipment nearby. I'll be recording again tomorrow, and will let it "warm up" after recording my main songs, and switch a voice, and record the erratic behavior..

I'm also going to get a can of compressed air, and use it to shoot cold air at some components, and see if it changes anything... I'm having a suspicion that a logic gate could be failing.. (think that's plausible?)

btw, i did some experimenting, and tried a PC double density drive on the DX7, and no change.. I also did the un-fun pleasure of checking all solder joints, and most traces this morning ;) what an experience that is.. all seemed perfectly fine..

i contacted Yamaha, but i doubt they have any DX7 motherboards left..

(i also have the service manual to the DX7 now, and it has nothing that even helps..)

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DX7IIFD won't work

Post by dachsis » Tue Jun 19, 2007 7:38 pm

Seems we have progress 'Houston', the shuttle is responding. I can add comments for twht they are worth (POINT#1) The DX7IIFD early FDD is Toshiba only. New models with 2 holes in diskettes will not work! Constant #1 problem on a IIFD is the stinkin FDD itself. Never buy cast-off used or "rebuilt" ones on E-bay. There is no such thing as a rebuilt FDD! New old style Toshibas ones are around, ck older computer repair shops . . (common #1 problem on my (2) SY77 [and on SY99 as well] is the BELT on the FDD, not the FDD itself. There IS NO FDD drive belts on a DX. (POINT#2) I agree with 'DX', PS is common ITEM also when heat is involved, most elect techs can repair locally. SIMPLY ADMINISTER COLD Air on PS to test it IN PLACE under ext operatons, same with cuircuit boards,,,,keep them chilled to test, pop a hair dryer on them to really test your suspicion of a heat-failing component.! ! 5 minute test! I can send you schematic. (3) DXIID PLUS is a very expensive serv shop conversion to bring a D up to a FD, the side panel and FDD install is only what you see, 1/2(?) of the elect guts have to be swapped to DX7IIFD inerds, I am told. I have schematics only on DX7IIFD, sorry. I have two units of DX7IID Plus(s). The most common enemy element in elect circuits and circuit boards is heat related maybe. Oh gotta brag a tad, I have a museum quality DX1, two DX5s, and A NEW CENTENNIAL. Don't hate me as all will be up for sale soon..eyes going away. Say one thing, you all sure have teamwork and perseverance on this bugger DX7IIFD I can say that. good go M8s.

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DX7IIFD won't work...

Post by dachsis » Tue Jun 19, 2007 7:48 pm

Almost forgot one thing borrowed from computer tech work... in that the FDD is not working you assume, a bad FDD in a computer can cause boot up and other problems. suggest you go in and disconnect the FDD totally and see...??? 2 minute test.

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Post by evildragon » Tue Jun 19, 2007 7:56 pm

i just gave a quick test on the FDD in my DX7.. I put it in my PC, and it is infact working, read all my floppy's too (minus an old IBM disk it failed to read "General Failure Reading Drive A:")..

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