Faulty TR Rack - No boot

Mhasseldam · Post by **Mhasseldam** » Tue Aug 09, 2011 7:25 pm

Hey guys, and a big hello, I'm new here!

I have a Korg TR Rack that does not work, and I don't know what's wrong with it. I have opened it, and I know a little about electronics, but I could not find anything that looked wrong inside of it.
It powers up when I turn it on, and the screen lights up but it does not boot up, no functions or information on the display, no buttons work. It have not been droped, and I have no idea what is wrong with.. You guys have an idea?
Also, does the TR Rack have an internal battery for memory? Because I could not find any. I know the Trinity does, I have that too. Fantastic machines!

It's wonderful to se these machines is still grooving in peoples hands! Fantastic!

Regards,
Martin

synthjoe · Post by **synthjoe** » Tue Aug 09, 2011 7:59 pm

TR rack stores data in Flash-ROM, so no battery. The service manual is available somewhere on the net, you can take a start from there.

It would be difficult to guess what the problem might be, starting from a loose connector to a bad component it could really be anything. Having the display backlight on means that your PSU is good enough to get the module started, so next question is whether power gets to the main board and does the reset cycle happen correctly. If LEDs above the buttons flash briefly when powering on, then you're fine up to the reset routine - so power failure will not be an option. In such case you'll need a fairly deeper analysis (address and data busses) to figure out what might be going wrong. There certainly should be a test routine, but I don't have the slightest idea how to get into it and whether it really exists... Even the service manual is mute about it.

Mhasseldam · Post by **Mhasseldam** » Tue Aug 09, 2011 8:03 pm

Hey Synthjoe
Thanks for the fast response!

That is what I thought too.. Damnit!
Can I somehow re-install the OS on the TR Rack to see if that solves the problem? If so - how?

synthjoe · Post by **synthjoe** » Tue Aug 09, 2011 8:25 pm

I don't think so. The only way would be via MIDI or serial, but I have no knowledge of the firmware file or a tool for that. And the question is open whether the CPU chip has a built-in FLASH, or mask programmed, or maybe it is stored in the external FLASH? Unfortunately I don't have any info on the Mitsubishi M31002S2HP single chip microcomputer.

Do the lights flash above the buttons when you switch it on?

Mhasseldam · Post by **Mhasseldam** » Tue Aug 09, 2011 8:49 pm

Yes, 3 of the diodes flashes while the other 3, combi, prog and global/multi, just lights up and stays on.. I den't remember, does they usually do that?

synthjoe · Post by **synthjoe** » Tue Aug 09, 2011 9:12 pm

No, it's not normal. Normally they flash and then go out, to come up steady when boot is over and the LCD displays meaningful information.

Since not all the LEDs behave the same way I'd think that reset and power is fine and so is the CPU. Reset and boot are initiated, and the LEDs you see are probably some coded error message, e.g. the boot phase where it gets stuck or indication of the component which fails the boot-up test. I don't think you'll be able to solve this yourself, unless a factory reset or test mode helps you, but for that someone will have to 'disclose' the key combination. Maybe you can do a search over the 'net.

Good luck!

P.S.: did you just buy it off SOS readers ads?

Mhasseldam · Post by **Mhasseldam** » Fri Aug 12, 2011 3:09 pm

Hi again synthjoe

Sorry for my late response - I have been away for a couple of days..
This is an old unit i have had for some years, I bought it used, but that is a while ago..

What exactly do you mean by "Key combination"?

Martin

synthjoe · Post by **synthjoe** » Fri Aug 12, 2011 3:43 pm

Mhasseldam wrote:What exactly do you mean by "Key combination"?

e.g.: pressing and holding 'reset' & 'A4' while powering on will do this and that...

There might be such key (button) combinations, but trying all possible 16,384 combinations of the 14 buttons would be nearly impossible, or at least extremely boring. So, if someone knows such combinations for 'reset', 'reflash', etc., then it would be good help to you and useful as future reference to others...

Mhasseldam · Post by **Mhasseldam** » Fri Aug 12, 2011 5:23 pm

Ahh, I see! I did not know that! Does every electronic instrument have that feature?
Well, thanks alot, synthjoe! Really appreciate your help! I will try to contact Korg and see if they can help (well, it doesn't hurt to try), and search the hole net. If I find anything that works I will post it here. And if anybody know such a key combination for the Korg TR Rack, it would be very helpful and appreciated!

Thanks again, synthjoe!

Martin

synthjoe · Post by **synthjoe** » Fri Aug 12, 2011 7:04 pm

Mhasseldam wrote:Ahh, I see! I did not know that! Does every electronic instrument have that feature?

No, but intelligent devices after the late '90s (with CPU and firmware) tend to have such functions. Still, not all of them, and I don't have a clue about the TR rack - but the Trinity keyboard version has such a service mode. Unfortunately, the keys used to enter that mode do not exist on the TR rack.

Mhasseldam wrote:I will try to contact Korg and see if they can help (well, it doesn't hurt to try)...

Thanks again, synthjoe!

Yeah, I would try that, too. Not at all, I wish I was able to help more...

Mhasseldam · Post by **Mhasseldam** » Fri Aug 12, 2011 9:21 pm

How do you enter that function on the Trinity keyboard?

Again, synthjoe! You have been really helpful! Thank you!!

synthjoe · Post by **synthjoe** » Fri Aug 12, 2011 9:43 pm

Mhasseldam wrote:How do you enter that function on the Trinity keyboard?

Warning: this erases all memory, so backup should be made of all user data before doing it. '5' and 'Enter' keys have to be kept depressed while powering up the synth.

Mhasseldam · Post by **Mhasseldam** » Sat Aug 13, 2011 8:15 am

Thanks for the info. It's always good to knows.

Do you know if it says anything about it in the Korg TR-Rack service manual? I can't find it on the net, only on eBay, and would just check before I purchased the manual..

synthjoe · Post by **synthjoe** » Sat Aug 13, 2011 6:38 pm

synthjoe wrote:There certainly should be a test routine, but I don't have the slightest idea how to get into it and whether it really exists... Even the service manual is mute about it.

http://www.korgforums.com/forum/phpBB2/ ... 768#361768

Mhasseldam · Post by **Mhasseldam** » Sun Aug 14, 2011 9:15 am

Arh sorry, you already wrote it..

Well, thanks a lot! You have been very helpful, synthjoe! Thanks!