Thinking about selling my damaged MT-32 for pieces...

[Maxime]

Hi All,

I recently retried to fix my MT-32 up, but I did not succeed. For those who don't know about my story, look at this thread: http://www.queststudios.com/forum/viewtopic.php?t=1267

A member of this forum sent me a MT-32 motherboard so that I can replace mine with it, but I (we) never managed to get it working. The LCD never indicates anything with the new mobo. Worse, after connecting/disconnecting/connecting/disconnecting/... the two motherboards for testing, the ribbon cables for the LCD are really damaged now.

I gave up, I had hope to fix this thing, but now I'm thinking about buying a new one and selling my current damaged stuff for a low price. I would like to know if anybody here would be interested, for the pieces which are still working, for example.

Quick description of my current MT-32, the one I would like to sell:
 * its mobo, with 2 L/R jacks, is noisy, but works anyway
 * the case is OK, except for the ribbon cables which are quite damaged, but the rest is fine: the LCD itself, the keyboard (no keys or knobs are damaged)
 * its original ACB-220 power supply

What I can also sell is a hand-made quite long 2 x male RCA to 2 x male 6,35 jack stereo cable, and a standard round MIDI cable.

About the additional mobo that someone sent me, I did not manage to get it working, although the sender told me it should be in OK condition. It has an additional phono jack. I have no intention to sell it (as I kindly received it for free), until the sender is OK with that.

Please note that I want to sell everything simultaneously, I don't want to sell the power supply to one person, the mobo to another one, the case to a third one... Many of you are from the US to the shipping costs will be lower, I guess, if I send everything to only one person

Please tell me if you're interested and which price you'd be ready to pay. I thought that it could interest somebody who needs a replacement MT-32 LCD, keyboard, case...

I have setup a donation space through Paypal on my website, so you can use it to pay directly online, using your credit card or any other thing supported by Paypal, in your own currency, instead of sending me a check, which is more "dangerous" and could involve high change fees (from dollars to euros for example) for me.

Thanks for all your help.
Maxime

[Cloudschatze]

Hey Maxime, I was beginning to wonder about you!

I sent Laust one of the same mainboards. He may discover something that I overlooked with regard to the installation. I understand your desire to wash your hands of everything though, and I can't blame you - this has been going on for some time now!

With this in mind, it's absolutely fine by me if you want to try and sell the mainboard for whatever you can get. I'm sure that someone out there may have an interest in it.

What I'd really like to see is some sort of conclusion to your ongoing dilemma. I can still help, I think, if you are interested in any of the MT-32 compatible modules. I have a spare CM-32LN and CM-64(still awaiting delivery), either of which I offer to you at no cost. The CM-64 is definitely the better of the two (in my opinion) - just reciprocate the good deed, whenever you get the chance; that's all I ask in return.

[Laust]

If you like, I would be willing to swap my working MT-32 1.07 board for your noisy 1.07 board. I think I stand a better chance of fixing the noise problem, which is probably an error in the analog circuitry. I have access to equipment, not to mention friends who have knowledge at this sort of thing.

My MT-32 main board has some "battle scars" from my desoldering of the ROMs and experimenting, but it is working 100%. We can swap whole MT-32's too, but since mine has a few cosmetic flaws (some wear and tear around the volume knob and one noticable scratch across the display), I don't know if you'd want that. And besides, just sending the board would mean less shipping charges for both of us

How badly are the LCD panel connectors damaged? and is the damage at the wires that go into the MT-32 main board or at the other end, soldered onto the actual LCD panel? The little fingers that go into the MT-32 main board are very frail, but it should be possible to cut away the bad parts, remove some new plastic to reveal the wire and then reapply some solder to the wires. This would make them good as new, and I think there is enough spare length to do so.

[Laust]

I sent Laust one of the same mainboards. He may discover something that I overlooked with regard to the installation. I understand your desire to wash your hands of everything though, and I can't blame you - this has been going on for some time now!

I just tried it out, and there were no problems. The only small caveat is that CN3 (power for the LCD display) connector is reversed on the new Mt-32 revision. Since the connector is keyed, there is no way you can plug it in incorrectly unless you force it, so it shouldn't be a problem.

The new revision main board also works without the LCD panel attached (I could enter the demo song mode and play a song fine).

[Maxime]

Thanks for your very nice replies guys!

I sent Laust one of the same mainboards. He may discover something that I overlooked with regard to the installation. I understand your desire to wash your hands of everything though, and I can't blame you - this has been going on for some time now!

You've perfectly understood my point!

With this in mind, it's absolutely fine by me if you want to try and sell the mainboard for whatever you can get. I'm sure that someone out there may have an interest in it.

What I'd really like to see is some sort of conclusion to your ongoing dilemma. I can still help, I think, if you are interested in any of the MT-32 compatible modules. I have a spare CM-32LN and CM-64(still awaiting delivery), either of which I offer to you at no cost. The CM-64 is definitely the better of the two (in my opinion) - just reciprocate the good deed, whenever you get the chance; that's all I ask in return.

Nice! You're a so cool guy...
But, with all my apologies, if I'm usually able to understand English quite well, I'm not sure to have fully understood your last sentence: just reciprocate the good deed, whenever you get the chance
Are you saying that you'd be ready to send me another Roland module if I get a chance to wipe away all my problems?

I just tried it out, and there were no problems. The only small caveat is that CN3 (power for the LCD display) connector is reversed on the new Mt-32 revision. Since the connector is keyed, there is no way you can plug it in incorrectly unless you force it, so it shouldn't be a problem.

Absolutely. On the new mobo Cloudshatze sent me, I had to cut out one side of the connector so that I could plug CN3 into it as my previous mobo, until I found that the reversed connector was "normal". But I cutted it gently, no harm has been done to the mobo :lol:. And the connector perfectly works as the LCD gets light.

The new revision main board also works without the LCD panel attached (I could enter the demo song mode and play a song fine).

Well, it's not my case, Cloudshatze will confirm that, we tried everything, but I never managed to get the mobo working, whereas my previous one worked well, even without the LCD.

If you like, I would be willing to swap my working MT-32 1.07 board for your noisy 1.07 board. I think I stand a better chance of fixing the noise problem, which is probably an error in the analog circuitry. I have access to equipment, not to mention friends who have knowledge at this sort of thing.

Nice deal!

My MT-32 main board has some "battle scars" from my desoldering of the ROMs and experimenting, but it is working 100%.

If it works without noisy sounds, it doesn't matter.

We can swap whole MT-32's too, but since mine has a few cosmetic flaws (some wear and tear around the volume knob and one noticable scratch across the display), I don't know if you'd want that. And besides, just sending the board would mean less shipping charges for both of us

Sending only the mobos annoys me, actually, because of my damaged ribbon cables, I'm afraid I'll never be able to hook your mainboard's LCD connectors to my MT-32 case.

How badly are the LCD panel connectors damaged? and is the damage at the wires that go into the MT-32 main board or at the other end, soldered onto the actual LCD panel? The little fingers that go into the MT-32 main board are very frail, but it should be possible to cut away the bad parts, remove some new plastic to reveal the wire and then reapply some solder to the wires. This would make them good as new, and I think there is enough spare length to do so.

They are damaged on the mainboard side. I did no soldering, but I tried to cut away the bad parts and removing some plastic parts, no luck, they are damn frail. I took pictures with my crappy digital camera so you can get informed of the "disaster". I think that it can be fixed (I have cut out very small parts of the cables), but I don't have enough knowledge and patience to do that. And, believe it or not, I spent near one hour to gently pull off the ribbon cables from my noisy mainboard, like Cloudshatze advised me, they became damaged after doing several times again and again.

So, if you are still ready for a swap deal, please let me know. Laust, if you could take some pictures of your MT-32 front panel, so I can see how "damaged" are the buttons or the LCD, it would be nice. Because if the unit has some scratches but works without being noisy, I would be quite interested by your swapping offer, unless the LCD is so scratched that it becomes clearly unreadable, of course (just as if you think that my ribbon cables are damaged at a point that you could not do anything to fix them).

Here is a bad-quality picture of my ribbon cables. All my apologies, my digital camera is quite old: http://maxime.abbey.free.fr/mt32.jpg

Thanks again for all your nice help, friends!

[Laust]

So, if you are still ready for a swap deal, please let me know. Laust, if you could take some pictures of your MT-32 front panel, so I can see how "damaged" are the buttons or the LCD, it would be nice. Because if the unit has some scratches but works without being noisy, I would be quite interested by your swapping offer, unless the LCD is so scratched that it becomes clearly unreadable, of course (just as if you think that my ribbon cables are damaged at a point that you could not do anything to fix them).

I guess it's wear and tear more than actual damage, but I'll borrow my brothers digital camera (better than mine) and take some pictures when he stops by tomorrow and then you can see for yourself.

Here is a bad-quality picture of my ribbon cables. All my apologies, my digital camera is quite old: http://maxime.abbey.free.fr/mt32.jpg

So long as there's enough wire to solder to and no damage to the actual LCD display, I should be able to fix it, so no worries.

[Maxime]

I guess it's wear and tear more than actual damage, but I'll borrow my brothers digital camera (better than mine) and take some pictures when he stops by tomorrow and then you can see for yourself.

OK. No problem!

So long as there's enough wire to solder to and no damage to the actual LCD display, I should be able to fix it, so no worries.

I've only cut out the equivalent length of wire that gets inserted on the connectors. So, yes, you should have fairly enough wire length to do a fix.

Only one ribbon cable has been cut out, the other one is nearly the same length as it was when I got the unit (I say nearly, because the wires would need to be cut as well, I think)

[Cloudschatze]

Maxime, yeah, I was offering a module. It sounds like you've got something worked out with Laust though (?), which is cool.

I'm still wondering if something happened to the mainboard I sent you during shipping. It seems likely, at this point.

[Maxime]

Maxime, yeah, I was offering a module. It sounds like you've got something worked out with Laust though (?), which is cool.

Yeah, I still have to see Laust's photos, to see how severe his MT-32's front panel is scratched, but I think that we found a deal!

But if you still want to offer me a module, I will not say no to a so nice offer :lol:. But you've already done so much for me...

I'm still wondering if something happened to the mainboard I sent you during shipping. It seems likely, at this point.

Maybe you're right. Althrough you packaged the mainboard very nicely... Maybe I did something wrong, even if I manipulated it very carefully (as I had many hopes using it to fix my problems).

Again, if you don't mind about that, I think that I'll send this motherboard to Laust as well, if we agree to swap our units. Maybe he'll be able to find what's wrong with it.

[Cloudschatze]

But if you still want to offer me a module...

I'd like to give Laust a shot at helping you first. It it doesn't work out though, then the offer is still there.

[Maxime]

I'd like to give Laust a shot at helping you first. It it doesn't work out though, then the offer is still there.

OK, I'm waiting for Laust's photos!
Thanks!

[Laust]

Okay, here are some photos. I can't compete with Cloudschatze for visual quality and the lighting conditions weren't optmal, but I think they get the job done

http://gallium.prg.dtu.dk/~lbn/mt32/

The scratched display is much more visible when the lighting is from the outside and up close (like with the camera). It isn't noticable when the only illumination is the backlight (and the characters are of course much stronger in contrast that the picture makes out). Anyway, now you know where you stand.

I also took a couple of pics of the insides of the unit. You can see that all the ROMs I desoldered were replaced with EPROMs. I did this to protect the sockets, since the pins on the desoldered ROMs weren't quite as clean as "fresh" EPROMs. I'll dig up and include the original ROMs as well, however. There's also a mystery switch in there .  It's a left over from an attempt to get more reverb modes out of the MT-32. The MT-32 (at least v1.07) has 32kb of algorithms for the reverb chip, but only 16kb is actually accessible by the system. The switch switches between the lower and upper 16kb half of the ROM. It makes some difference when you hit the switch, but I never figured out exactly what the difference is... The switch is in the OFF  (=original) position. I can remove it, but would just as well leave it be. It doesn't affect the output at all.

I also did a couple of test recordings. The LSL3 and HOC MIDIs came from this site.

[Maxime]

Thanks for the stuff Laust.

I'm OK for the deal. Clean sound! Your volume button seems OK and the scratch on your LCD should not be a big issue (at least, far much more acceptable than my noise problem, for me), especially if you consider that I place the unit just above my keyboard, on my left, so it should be less visible than on your photos.

I'll retest my unit to check if everything is OK apart from mentioned issues (noise, damaged LCD ribbon cables), and, if my digital camera accepts to take unblurred photos, I'll take some additional pictures.

EDIT: I've tested the unit after putting the case on it, it works. Noisy, as usual, but... The MIDI message LED flashes, the volume knob works, as well as the other buttons (I tested several combinations, such as Master Volume + Volume keys) and its answers to my master MIDI keyboard.

I'm sorry I could not take more photos, my digital camera only gave blurry results.

I've sent to you my postal mail address in PM. I'm waiting for yours!

[Maxime]

Wow... I can't believe it...
I just received Laust's module today...
No noise... I had to wait nearly one year to have this clean sound...

Thank you so much, Laust. For the first time, I'm fully happy with an MT-32. Many thanks to you and to this absolutely great forum, which has been the only one to offer me concrete help.

I sincerely hope that you'll be able to fix mine, you said that yours had little cosmetic scratches, but they are so insignificative compared to the satisfaction I have now...

I'm now fully able to record MP3s from some MT-32-enabled game soundtracks I did not find anywhere (Operation Stealth aka. The Stealth Affair and Future Wars: Time Travellers), and I'll also have nice material to record additional sounds for my Sound Blaster Live! card.

Some months ago, I also started to build a GM transformation SysEx bank for this nice little module, I can now continue to enhance it, to play GM MIDIs on the MT-32.

Thank you so much, friends. I'll never forget that.
Maxime

[Caliburn]

This thread is a perfect example of what I love about the people on this forum.

Let us know, Laust, what you discover about the cause of the noise.  I'm not very tech-minded, but I'm still curious to hear how this turns out.

Take care,
-Luke

[Laust]

I'm glad to hear it's working for you, Maxime I'm still waiting for your unit, I guess it'll be here within a few days.

I feel pretty confident the problem with Maxime's old unit is in the analog parts of the synthesizer - post-DAC sound stage or the power supply section. Either of these should be reasonably easy to fix and all the components are standard. I will post my progress here.

[Maxime]

I hope you'll receive my package soon Laust.
It has been posted as "prioritary" mail, so
Maybe its heavier weight has something to do with longer delays. I hope that the extra protection will not be useless, at least :roll:
I'll keep an eye on your progress with my unit.
Thanks again.

[Laust]

Before I forget, I already recieved Maxime's package, last week. Everything arrived safely.

Currently I'm working on getting the LCD panel working, then I will look into the noise problem. I replaced the LCD cables (seemed easier than trying to fix them) and now the LCD panel works in another MT-32, but in this one it remains blank (backlight turns on, but that's it), so there must be something wrong on the main board itself. The two white LCD connectors on the board are pretty worn and have almost no tightness (meaning poor electrical connection), so they are likely culprits and candidates for replacement.

Another thing I noticed, is that the voltage regulator (the little three legged thingy sitting on the metal case), which is supposed to output +5V (and is the main supply voltage for the ICs), is only at +4.2V! This either means it's gone bad, or there is something like a short circuit on the print and it is pulling down the voltage. +4.2V is probably high enough that things would run, but at the same time so low that some strangeness might occur, so it could easily be linked to the noise problem...

[Maxime]

Hi Laust,

I was starting to wonder about you

Glad you received the package in good condition, I was wondering if it had not been blocked somewhere in the postal circuit, as I received your MT-32 nearly 15 days ago!

I was sure that the cables were too damaged to be fixed efficiently, so it's nice to have replaced them, but I wonder why they don't work with the noisy mainboard anymore! Even when the old cables were in bad condition, I once managed to get the LCD working, as long as each cable was in its own connector part... but you're right, maybe they have been untightened because of removing/replacing/removing/replacing/... the ribbon cables several times. I hope that you'll be able to replace or fix them as well.

But the problem you've noticed with the voltage regulator is actually quite strange! I had no idea about that, and the previous owner of the unit said me that it had always been in a home-studio, so I wonder when this problem has occured... One thing is for sure, if this problem is linked to the noise, it was already present before I got the unit.

I hope that you'll manage to get this working.
I'll keep an eye on this topic to follow your progress.
Thanks again for your help, your unit fully satisfies me, and I hope that mine will soon work again for you.

[Laust]

The LCD is fixed now. Since I wanted to solder as little on the LCD module as possible (and prevent future problems), I decided to replace the two cables with two rows of pinheaders:





And here's the connector cable made with a little piece of veroboard and a female 2x6 pinheader, plus two ribbon cables:



Although this is also a bit frail, at least it should be easier to resolder if it ever breaks...

I also replaced the two connectors in the MT-32 with the much sturdier pinheaders:



The cables fit like a glove (two gloves actually ):



And here's the whole thing:



Next up I replaced the voltage regulator. This definitely made some difference, removing the background whining noise:

http://gallium.prg.dtu.dk/~lbn/mt-32_before.flac
http://gallium.prg.dtu.dk/~lbn/mt-32_after.flac

But as you can hear there are still problems with the audio, it distorts quite badly. I don't know what's causing that, the investigation continues...

Somewhat ironically, the voltage regulator is the one component Maxime would have been able to replace himself as it isn't soldered. It also means that if he had gotten the extra MT-32 main board from Cloudschatze (which I haven't looked at yet) to work, it wouldn't even have solved the problem (or not all of it) as the voltage supply was bad.