System Error UND

[massimo]

Hi all,

I have owned an EIII rack for the last two years.
Now, it starts doing funny things when I turn it on:
1. All front panel lights on, and machine frozen
                          or
2. No characters on the display
                          or
3. Black squares instead of characters on the display
                          or
4. System Error UND message. This latter more often shows up some time (10 to 120 minutes or so) after the machine has turned on and worked successfully, and obviously freezes the box, being often accompanied by output of a screaming sound...

I have searched the forum, and found mention of the System Error UND message, but without an explanation of what it means (or I may have missed that)

Help anyone?
best regards
Massimo

[midipuppies]

1: Check the system bus cards are seated correctly.
2: Check the big ribbon cable between the front panel and card cage is secure.
Seen this on one of my units before and it was that big ribbon cable. It had an intermittent connection in the ribbon itself AND the connector at the panel side was not making contact properly.
What does the hard disk sound like? Does it stay running consistently?

[massimo]

Hi Midipuppies,
thank you
so it looks like you also saw that vaguely German-sounding message (und)...

yes, the hard disk runs consistently, so it seems to me. Also, since it is not a permanent damage, but an intermittent problem, my (non-technical) feeling is that it is a connector issue. But, what do I know?
I will check those ribbons (not now, it is 2.00 a.m. ...)

again, many thanks
best regards
Massimo

P.S.: by the way, layering the E3 with the Oberheim Xpander is...I often find myself, at the ripe age of 53, speechless. It is incredible how a sampler can have the same organic quality as an old analog poly. E3 rules! (I had to write this, sorry)

[massimo]

bad news,

the problem gets worse...
When I turn the E3 on, I have either blank display, or black squares and all button lights on, and so on. Only rarely, after several attempts, will the box decide to work properly. I have detached the big front panel ribbon cable, and sprayed Deoxit. Also, I have gently shaked that cable with the machine on, to check if there is some false contact. No results. I do not know where the system bus cards are.
I talked to my tech here in Rome. Based on my reports, he said it must be the internal System IC dying (he says this is expected after 20 years), and there is nothing he can do. He suggests that leaving the machine on for several hours, even if not working, helps "refreshing" that IC temporarily.
I am now very sad.
Anyone?

best regards
Massimo

[massimo]

..."evil" display (blank, or black squares, whatever), generally refuses to boot the system from the floppy (the disk keeps spinning, or the floppy drive does not start spinning at all...) or, should it graciously boot and load the system, works fine for 30 to 120 minutes, then the infamous System Error UND appears, and it's all frozen.
But it is getting more and more difficult to make it come to life anyway.
One word: desperate

Anyone?

best regards
Massimo

[dr.c]

Are you sure that the flat cable coming from the front panel doesn't get pinched against the card rack when you close the machine ?

[massimo]

Yes, I have the rack open at the moment, so no pinched cable, unfortunately...

thank you
best
Massimo

[dvdborn]

You may want to check if the power supply is still providing the right voltage values.

[moogah]

Just bumping this thread to say I've got an EIII keyboard with precisely the same symptoms.  It would be great to get some information about "System Error UND".

Thinking about it for a bit, although UND does indeed have a vaguely German sound to it (I thought the same), knowing that E-MU was an American company I would suppose that UND is either an error code (or codes) which we are not likely to decipher here.. or it could simply be implying that it's detected an UNDer-voltage somewhere.

This gives me some hope since I don't really relish the idea of tracing my way through the processing board looking for a problem (while my EIII was working I was able to load the UST diagnostic programs and confirm that all 16 voices play more or less fine).

[esynthesist]

"System Error UND" means "System Error Undefined OPCODE" which is one of the possible flags which will be set by the CPU used by the EIII if this CPU goes crazy :-)

In my opinion it's not really possible to link this kind of CPU state to a certain hardware part of the EIII - the CPU has gone in an unexpected state due to unexpected signals, but any failure in the circuits could be the cause of these unexpected signals I assume...

The PSU could be the first one to look at of course, because it drives all circuits and strange signal levels can be due to bad power (as always...)

[moogah]

1000 thanks for that information! 

For the benefit of the group, here is where I'm at with my EIII:

I've taken the top off (disclaimer: Ive got experience with electronics, have a proper workbench and have read the service manual) and attached a multimeter to the 5v power rail.  Leaving the EIii on for a while (with an arpeggiator running) I can see the 5v rail slowly droop.  After about 2 hours the EIII was still playing but 5v was down to about 4.7v.  Unfortunatly I did not have the patience to wait and see if this drop would continue and cause the UND message.  Instead I was curious to prove that  heat was a factor in the drooping, a gentle foofing with a can of air immediatly brought the rail back to 5v.

I also discovered that the EIII is very sensitive to changes on the 5V rail.  I attempted to adjust the trimpot and it glitched unhappily and then reset itself (breifly producing the tone at it's output).  Even he slightest touch of the trimpot would cause problems.

Next steps: produce System Error Und from letting the 5v rail droop.

[who]

Thanks Midipuppies!  Your suggestion below seems to have worked for me. 

2: Check the big ribbon cable between the front panel and card cage is secure.

[who]

I think the same may be true with the ribbon on the external SCSI connector.  Since reseating the cable to the panel, I've only seen the "system error" once and that was after moving my CDROM drive.  I then reseated the connector to the external SCSI and haven't seen the error since.

[brian_ronn]

Hi Emu fanatisk

I managed to resolve the 'system error und' error on my EIIIrack with help from fellow Facebook users.

Maybe this is the solution for you if you have the same EIII error.

Here goes.:

I replaced the 60 pin ribbon cable between the card case and the front panel since this cable often get pinched between the top cover and the card cage.

Then I pulled out the CPU card (the second from the left) and changed the sequence between the 4 CPU ram (MB81464-) chips and put the cpu card back again. By doing this the machine stayed alive a lot longer than usual. This indicated that one or more of the CPU ram was faulty. Therefore I ordered and replaced all 4 CPU ram. This did the trick for me and has solved my 'system error und' freezing up problem.

Sometimes this problem has to do with the 60 pin ribbon cable other times it is due to faulty CPU ram and sometimes the PSU or other things. But these suggestions might solve your 'system error und' problem too.

Best regards Brian