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Korg T1 dead, trying to get it back to life ! [SOLVED]

 
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freetmool



Joined: 13 Mar 2019
Posts: 3

PostPosted: Wed Mar 13, 2019 1:05 pm    Post subject: Korg T1 dead, trying to get it back to life ! [SOLVED] Reply with quote

Hello,

This T1 doesn't do anything when I turn it on, no screen, no floppy loading sounds, nothing...

What I've done so far:

- I fixed the power supply, now it works ok, 5v, +-12v good. (still no sign of life)
- I tested the screen with an arduino, work perfectly.
- I have desoldered and tested all M5M4464AL memories because one of them was burning hot. So except that hot memory everything is OK. (still no sign of life)

- I have removed the two EPROMs and now I see a blinking, scrambled screen, leds blinking too ...

Could it be bad EPROMs ?
Where could I find the file to reprogram it ?

Thank you Smile


Last edited by freetmool on Mon Mar 18, 2019 4:15 pm; edited 1 time in total
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T3owner
Senior Member


Joined: 17 Jun 2011
Posts: 336
Location: USA

PostPosted: Sat Mar 16, 2019 6:03 pm    Post subject: Re: Korg T1 dead, trying to get it back to life ! (need advi Reply with quote

freetmool wrote:
Hello,

This T1 doesn't do anything when I turn it on, no screen, no floppy loading sounds, nothing...

What I've done so far:

- I fixed the power supply, now it works ok, 5v, +-12v good. (still no sign of life)

Did you check the supply voltages at the KLM-1370 main board, after the on-board filtering?

 
freetmool wrote:
- I tested the screen with an arduino, work perfectly.
- I have desoldered and tested all M5M4464AL memories because one of them was burning hot. So except that hot memory everything is OK. (still no sign of life)

There are 13 of those memory chips in a T1 - five on KLM-1370 (IC32~IC36), and eight on the KLM-1385 PCM ROM/RAM board. (EDIT: Also IC37~IC44 on KLM-1370) The ones on KLM-1370 are critical. The eight on KLM-1385 can be left out - they are just used to load samples - when not mounted, a T-series model will otherwise work.

Which chip was running hot?

 
freetmool wrote:
- I have removed the two EPROMs and now I see a blinking, scrambled screen, leds blinking too ...

Could it be bad EPROMs ?
Where could I find the file to reprogram it ?

Thank you Smile

Send me a PM with your email address.
_________________
Korg: T3EX, 05R/W | Yamaha: Motif XF6 and XS6, A3000V2, A4000, YS200 | Fender Chroma Polaris | Roland U-220 | Etc.


Last edited by T3owner on Mon Mar 18, 2019 5:56 pm; edited 1 time in total
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freetmool



Joined: 13 Mar 2019
Posts: 3

PostPosted: Mon Mar 18, 2019 2:43 pm    Post subject: Reply with quote

Thank you for the reply !

Well, today I've received some new M5M4464al and I've populated every single one on the KLM-1370 and it works like a charm Smile
You were right. Critical Wink
No need for eprom files.

Just a note, there are 13 critical M5M4464al on the KLM-1370
and 8 non critical MB81C4256 on the KLM-1385.

Thanks again T3owner !
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