Problem with Mirage

HxC Floppy Emulator Ensoniq Keyboards/Samplers support
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edohxc
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Joined: Mon Apr 04, 2016 5:10 pm

Problem with Mirage

Post by edohxc » Mon Apr 04, 2016 5:21 pm

Hi all!

I just got my Mirage back after a tech mounted the floppy emulator.
He didn't have a card to test so I tried to prepare one on my Windows XP PC but no luck.
So I bought a card on eBay containing 150+ disk images hoping that it will work and that the card made by me was not working because of my ineptitude.
But this card behaves the same so maybe something is wrong with the connection or the jumpers... I don't know.

I proceed as follows:
1) I insert the card in the slot
2) I switch on the Mirage
3) The screen displays "Reading FAT" and then "A_edm.hfe Choose a file"
4) I push the button in the middle and the screen displays "A_edm.hfe RA T:002/080 S:1"
5) If I push the button in the middle I go back to 4)... and so on forever

In the meanwhile the Mirage display shows only the 2 upper lines and the buttons on the front are inactive. It seems like frozen.

I have a Mirage rack.

Any help would be really appreciated!

Thank you!

Ed

EDIT: Just found out that I had to reverse the cable. Now everything works!

Jeff
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Re: Problem with Mirage

Post by Jeff » Mon Apr 04, 2016 8:48 pm

edohxc wrote:
4) I push the button in the middle and the screen displays "A_edm.hfe RA T:002/080 S:1"
[...]
EDIT: Just found out that I had to reverse the cable. Now everything works!
Exactly : The display showed that all floppy ribbon signals was stucked to the ground ;).

edohxc
Posts: 8
Joined: Mon Apr 04, 2016 5:10 pm

Re: Problem with Mirage

Post by edohxc » Tue Apr 05, 2016 1:54 am

Thanks Jeff!


I have one question: is there a backlight behind the LCD? Mine has no backlight and it's hard to read.


Many thanks!

Ed

edohxc
Posts: 8
Joined: Mon Apr 04, 2016 5:10 pm

Re: Problem with Mirage

Post by edohxc » Thu Apr 07, 2016 4:53 pm

Really no one knows???

mondo1976
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Re: Problem with Mirage

Post by mondo1976 » Thu Apr 07, 2016 10:51 pm

The LED display should be amber colored with a tendency to flicker/strobe fairly rapidly. If it isn't then something is wrong somewhere.

If you've got a multi-meter and know how to check voltages, the 4-pin harness on the power supply should carry +5VDC and +12VDC and the 6-pin harness closest to the 4-pin harness should carry -12VDC. The other harness leading to the transformer is all AC, so I'd avoid probing that.

The easy thing to try is re-seating the J2 connector on the mainboard and/or spraying it with some DeoxIT.

edohxc
Posts: 8
Joined: Mon Apr 04, 2016 5:10 pm

Re: Problem with Mirage

Post by edohxc » Fri Apr 08, 2016 4:15 pm

mondo1976

First of all thank you for your reply!

Can it be that you are referring to the 2 digit Mirage display? That's fine here!

I have a problem with the backlight (if it exists!) of my HXC floppy emulator!

Ed

mondo1976
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Re: Problem with Mirage

Post by mondo1976 » Sat Apr 09, 2016 3:08 am

edohxc wrote:Can it be that you are referring to the 2 digit Mirage display? That's fine here!
I have a problem with the backlight (if it exists!) of my HXC floppy emulator!
Ha, ha, ha. My mistake. I'm so stupid! :D

I figured you meant the Mirage because people are always concerned about the flickering and your first post mentioned the Mirage display. Whoops.

If you have the standard HxC and not a Gotek HxC then yes, there's a backlight. Is there absolutely no backlight at all? Or is the text just hard to read?

If there's actually a backlight but the text is hard-to-read or dim, then I'm pretty sure there's a contrast adjustment pot on the HxC board which you can adjust to taste.

But since it sounds like your problem is total absence backlight:

I could be wrong here (I didn't design the HxC nor do I even own one), but EL backlights tend to dim and not just totally die, unless there's a bad wire/trace somewhere. If the backlight isn't working at all then the EL panel itself is probably still fine, just with a bad connection to power or the like.

Since the whole HxC board is run off the same 5v source, there has to be a bad connection from the mainboard to the LCD board (14+2 or straight 16 pin connector, I think), or from the LCD board to the backlight (2 thin wires most likely, on the right side of the LCD assembly probably).

See if there are two wires labelled A and K, BL+ and BL-, or VB+ and VB-. If not, then there should be 16 wires running along the top edge of the LCD board. If so, then double-check pins 15 and 16. Any of the above pairing of pins/wires could be where the backlight fault is.

Like I said, I could be way off with this so take it with a grain of salt, but unless someone else has a definite or more elaborate answer for you then that's my guess.

Edit: Found the schematics (or one version of them, at least) and it looks like there's an LCD backlight control hooked into the front panel connector. Try looking at Q3 or R31. Q3 would be much more likely to die than R31, but it's conceivable there's a bad solder joint at either.

I don't know how handy you are with a soldering iron, but you might try replacing Q3 or just jumping the emitter and collector on Q3. In other words, there are 3 legs on Q3. The one leading to resistor R31 you'd leave alone. You'd connect the other two legs together which connects the LCD backlight line to VSS/ground.

Jumping Pin 1 to Pin 16 on the LCD should accomplish the same thing. Anything connecting Pin 16 to ground should activate the backlight, I believe.

Basically, in this scenario, you've got Pin 15 on the LCD being supplied power for the backlight. Pin 16 needs to go to ground to complete the circuit which enables the backlight, but if the Q3 transistor can't close then Pin 16 will never close either. So all we do is manually close the ground by bypassing the transistor. Q3 would usually close itself when the PIC chip sends voltage to the base of Q3 (the leg touching R31), but if Q3 was shorted somehow then it definitely could have stuck itself open.

The easy way to test the Q3 theory would be to hold a small screwdriver tip against those 2 legs on Q3. If your backlight flicks on then you've probably got a bad Q3. Only do this if you're feeling gutsy and risky. Don't slip!

If any of that sounds too sketchy, then wait for Jeff :)

Total guess work, and I'm not an expert by any means.

edohxc
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Re: Problem with Mirage

Post by edohxc » Sun Apr 10, 2016 12:15 pm

Hello mondo1976!

Thank you so much for your time!

I have a Lotharek and I will try to check what's wrong but I fear it's technically too difficult for me. Even with your fantastic explanations I am not sure that I can check all those things...

I hope Jeff maybe has a hint for me, something I can easily try. The Lotharek is perfectly working, only the backlight is not there which is a real problem for me.

THANKS!

Ed

mondo1976
Posts: 141
Joined: Mon Dec 28, 2015 3:54 pm

Re: Problem with Mirage

Post by mondo1976 » Sun Apr 10, 2016 2:19 pm

edohxc wrote:I have a Lotharek and I will try to check what's wrong but I fear it's technically too difficult for me. Even with your fantastic explanations I am not sure that I can check all those things...
Really the only real danger in testing the negative backlight theory is being clumsy and having "fat fingers". If you had some tiny alligator clips then all you'd need to do is clip a wire to pin 16 of the LCD panel, and the other end of the wire to something grounded. Accidentally shorting pin 15 to 16 is the danger there, but as long as they aren't touching each other before you turn anything on then you should be fine.

The brute style of testing would be to cut the pin 16 LCD wire at the mid-point, strip the fresh "end" that leads back to pin 16 and tap that to something grounded. If your backlight flashes then you've got your fix.

It all depends on how desperate you are though. If you've got time and are under warranty of some kind then I wouldn't want you to take my advice. If you're in the middle of nowhere with no help and need to get this thing fixed, then it's about the easiest electronic fix/test possible.

Don't do anything you're not comfortable with of course.

Jeff
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Re: Problem with Mirage

Post by Jeff » Sun Apr 10, 2016 11:46 pm

edohxc wrote:Hello mondo1976!

Thank you so much for your time!

I have a Lotharek and I will try to check what's wrong but I fear it's technically too difficult for me. Even with your fantastic explanations I am not sure that I can check all those things...

I hope Jeff maybe has a hint for me, something I can easily try. The Lotharek is perfectly working, only the backlight is not there which is a real problem for me.

THANKS!

Ed
Just try to unplug and replug the lcd ribbon.

edohxc
Posts: 8
Joined: Mon Apr 04, 2016 5:10 pm

Re: Problem with Mirage

Post by edohxc » Mon Apr 11, 2016 6:18 pm

Jeff, do you mean the connection called "J4"?

Jeff
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Re: Problem with Mirage

Post by Jeff » Tue Apr 12, 2016 8:44 am

edohxc wrote:Jeff, do you mean the connection called "J4"?
Yes. Unlock it, remove the ribbon, reinsert the ribbon, lock it.

edohxc
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Joined: Mon Apr 04, 2016 5:10 pm

Re: Problem with Mirage

Post by edohxc » Fri Apr 15, 2016 9:09 pm

Hi Jeff!

Thank you for your suggestion, I did how you said but nothing changes: everything is working fine but no backlight.
Can it be that my Lotharek is defective? Are there other things I can try/test?

Thanks!

Ed

edohxc
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Re: Problem with Mirage

Post by edohxc » Fri Apr 22, 2016 2:11 pm

Jeff, what should I do? Should I send back my Lotharek drive for checking? Maybe it is defective... I really have no idea...

Thanks

Ed

Jeff
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Re: Problem with Mirage

Post by Jeff » Sat Apr 23, 2016 9:03 am

Yes please contact Lotharek.
don't forget to give me the link to this thread into your email.

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