T3 PCM RAM INSTALLED BUT NOT WORKING

[marvinle]

Hi, everyone,

I'm a new member of Korg Forum as I'm a new owner of an old T3. I'm really happy with it. At first I wanted an M1 but finally chose the T3.

I had to change the battery and I was happy to see the PCM RAM BOARD
KLM-1385C installed.

But it doesn't seem to be activated . It's doesn't appear in the self check.

Does anyone know how to make it work ? Please !
Thank you for your help

MarvinLee

[T3owner]

The KLM-1385 board is not just for PCM RAM - it's where the PCM ROMs are found. Without that board, your T3 would have no source for sounds.

The eight PCM RAM memory chips (UPD424256V-10 or equivalent) were factory installed in a T1 (to positions IC9~IC16), but were unpopulated on the original T2 and T3. The later T2EX and T3EX had the PCM RAM factory installed, and the earlier T2/T3 can be retrofitted.

Check for chips at IC9~IC16 on the KLM-1385.

[marvinle]

Hi, everyone,

I'm a new member of Korg Forum as I'm a new owner of an old T3. I'm really happy with it. At first I wanted an M1 but finally chose the T3.

I had to change the battery and I was happy to see the PCM RAM BOARD
KLM-1385C installed.

But it doesn't seem to be activated . It's doesn't appear in the self check.

Does anyone know how to make it work ? Please !
Thank you for your help

MarvinLee

Awesome ! Thank you for your prompt answer ! Now I understand everything !
IC9 to IC16 are empty. I noticed the difference with the T1 board !

Do you know where I can find them ?
MarvinLee

[T3owner]

[Awesome ! Thank you for your prompt answer ! Now I understand everything !
IC9 to IC16 are empty. I noticed the difference with the T1 board !

You're welcome.

Do you know where I can find them ?
MarvinLee

That might depend on where you're located.

Part search sites:
https://www.findchips.com/
https://octopart.com/

The uPD424256V-10 is an NEC brand 256k x 4 fast page RAM, 100ns(nanoseconds) speed, in a 20-pin ZIP package.

Some equivalent part numbers:
HM514256AZP-10 Hitachi
M5M44256BL-10 Mitsubishi
TMS44C256-10SD TI (Texas Instruments)
TC514256AZ-10 Toshiba
Several other manufacturers made equivalent devices. If you find something else, make sure the speed is no less than 100ns and it's in a ZIP (not DIP) package.

Example of an acceptable slightly faster chip:
TMS44C256-80SD TI brand, 80ns

Some manufacturers leave a pin out (so 19 pins). The KLM-1385 has no connection at the matching location.

EDIT:
Only eight chips are needed, but price for 20 seems reasonable...
http://www.ebay.com/itm/20PC-NEW-TOSHIB ... 1604870375
These will likely work, but I suggest asking seller to verify equivalence to uPD424256V-10 before purchasing.