E-mu Emulator Sampler User Forum for the EIII EII EI and EIII XP

General Category => Emax II Technical Issues / Tips => Topic started by: JAW on May 15, 2010, 05:34:19 PM



Title: EMAX II Memory problem
Post by: JAW on May 15, 2010, 05:34:19 PM
Hi,

My Emax II has sort of died. At startup it says WARNING! Sound MemorySize Error. Ik can load a sound bank, but it sounds like static. The GRAM test in the hidden menu also gives an error, almost immediately. Can anyone tell me if this is fixable or has my Emax turned into a very heavy (but cool looking) midi keyboard?
 
Cheers!




Title: Re: EMAX II Memory problem
Post by: midipuppies on May 16, 2010, 10:25:09 AM
Not a good sign my friend.
I would say that you have lost a ICU or two.
How much ram is on board?


Title: Re: EMAX II Memory problem
Post by: JAW on May 16, 2010, 11:50:09 AM
Hi,

It's a 2MB with an expansion board with another 2MB. It doesn't matter if the expansion is in or out. Buying a new one is probably cheaper than having this one fixed. The sell for around 125 EUR...




Title: Re: EMAX II Memory problem
Post by: dr.c on May 16, 2010, 01:07:49 PM
You have a problem : when you put a memory expansion, there is a diskette wich goes with it. This diskette programs an EEPROM in order to give the amount of memory.
If the EEprom is erased (it can happen in per example, you put an S1000 Akai disquette into the Emax by mistake, it will return you this error.
Try to find a disquette, you can duplicate it with an ATARI.


Title: Re: EMAX II Memory problem
Post by: JAW on May 16, 2010, 03:08:26 PM
Hi,

I've been googling, but have not come accross any eeprom disc. They're hard to find because they selfdestruct, right?

Does anyone know where to find such an eeprom disk?




Title: Re: EMAX II Memory problem
Post by: dr.c on May 17, 2010, 09:03:34 AM
Geeeee... I don't know... But as soon as you have one, find a copier on Akai and make duplicates !!!!


Title: Re: EMAX II Memory problem
Post by: dr.c on May 17, 2010, 09:06:38 AM
Just as a try : could you make a picture of the inside card, especially the place where the memory is !
You may have a bad scratchpad memory. I will edit the pic by photoshop with explanations and put it back here.


Title: Re: EMAX II Memory problem
Post by: JAW on May 17, 2010, 12:37:48 PM
Hi,

I really appreciate your help! I hope you can tell something from the pictures. You can find them on http://www.flickr.com/photos/50282271@N04




Title: Re: EMAX II Memory problem
Post by: dr.c on May 18, 2010, 10:47:42 AM
Okay...

I need to know wich is the reference of the circuits on the yellow frame.

The circuits having blue and red frames are memories and you can try to swap them, it may help a lot.
At this point, depending of the kind of memory failure, you may either have the same problem, or sound garbage, because some of the memory is used for machine management. But I am not sure, this is why I need to know wich are the yellow ones.

For the picture, go to : http://mapage.noos.fr/dr.c/SCRATCHPAD_a.jpg (http://mapage.noos.fr/dr.c/SCRATCHPAD_a.jpg)

Are the yellow ones the same as the others (red/blue) ?




Title: Re: EMAX II Memory problem
Post by: JAW on May 18, 2010, 05:45:13 PM
I swapped the red and blue ones. Same static sounding garbage. The yelllow ones are different. You can see it in the picture. Do you need more specific info?


Title: Re: EMAX II Memory problem
Post by: dr.c on May 19, 2010, 02:25:32 AM
Well, at this point, there is no miracle, you need a scope and check the data and adress lines of the memories.
Still the same garbage if you don't put the expansion card ?


Title: Re: EMAX II Memory problem
Post by: JAW on May 19, 2010, 03:54:36 AM
I have a second Emax II that works just fine. It's a newer type and if I remember correrly, all memory chips are fixed to the board. I'll check it tonight. If they're not fixed, I can put them in the other Emax. I'll let you know.




Title: Re: EMAX II Memory problem
Post by: dr.c on May 19, 2010, 03:11:25 PM
The best way to have two machines dead...


Title: Re: EMAX II Memory problem
Post by: JAW on May 20, 2010, 01:10:11 AM
I prefer two machines alive  :)

I made some progress:
I put the red & blue from the working Emax in the not working one. At startup I dont get the sound memory error anymore, but only when I also plug in the memory expansion. However, I still get the screwed up sound (only noise) and in the GRAM diagnostics, I get the following message: is:A960 sb: 1234 ic#??addr:400001. The funny thing is that the red & blue chips work fine in the other Emax. The problem is, that the yellow chips in the working Emax are fixed to the board, so I cannot swap those. I guess I need some professional equipment and knowledge to find out the real problem, right?




Title: Re: EMAX II Memory problem
Post by: dr.c on May 20, 2010, 11:21:53 AM
Do you get normal sound when you don't put the expansion card ?

You are not clear !

Apparently, a dead chip on the expansion card...


Title: Re: EMAX II Memory problem
Post by: JAW on May 20, 2010, 01:04:31 PM
Without the memory expansion I get the same noise but also the memory error. With the expansion installed I get no error but I do get noise.




Title: Re: EMAX II Memory problem
Post by: rtech on February 09, 2012, 01:19:20 PM
Hey everyone,

 I just got a hold of an Emax II Stereo with 4MB RAM. When I boot I get the memory error stated in the beginning of this thread. When I run the GRAM test in the special menu I get the following Errors:

Without the memory expansion board installed the error is:

 IS: 0F00 SB: 5678
 IC#?? Addr: 400000
 

With the memory expansion installed the error is:

 IS: C99A SB:C112
 IC#?? Addr: 100000

Does anyone here know how to find out which RAM IC is the culprit or is there a guide on how to convert the address to the IC numbers? My board looks exactly like the ones in the picture posted by JAW.

Thanks


Title: Re: EMAX II Memory problem
Post by: esynthesist on February 09, 2012, 03:03:08 PM
Here's the information from the Emax-II service manual:
(...)
Convert the (data is)        IS Hex Value to its Binary Value
Convert the (data should be) SB Hex Value to its Binary Value
Find the bit(s) which differ(s).
Use the information below to find the IC#s that may cause the problem, based on the "problem bit".
Swap around ICs corresponding to that bit to find the defective IC.


MAIN BOARD 256K RAM
Bits 0-3:   IC# 46, 50, 56, 60
Bits 4-7:   IC# 47, 51, 57, 61
Bits 8-11:  IC# 48, 52, 58, 62
Bits 12-15: IC# 49, 53, 59, 63

MAIN BOARD 64K RAM
Bits 0-3:   IC# 64, 68, 73, 77, 82, 86, 92, 96
Bits 4-7:   IC# 65, 69, 74, 78, 83, 87, 93, 97
Bits 8-11:  IC# 66, 70, 75, 79, 84, 88, 94, 98
Bits 12-15: IC# 67, 71, 76, 80, 85, 89, 95, 99

MEMORY EXPANSION BOARD
Bits 0-3:   IC# 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48
Bits 4-7:   IC# 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47
Bits 8-11:  IC# 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46
Bits 12-15: IC# 1, 5,  9, 13, 17, 21, 25, 29, 33, 37, 41, 45
(...)

But... in your Emax-II many bits are different, so I'm not sure it's "just" an IC problem.

///E-Synthesist


Title: Re: EMAX II Memory problem
Post by: rtech on February 09, 2012, 09:46:21 PM
Thanks Esynthesist,

  I reseatted all socketted chips including all the ram chips on the mainboard, and I plugged in the expansion board and it booted without any memory errors. I ran the memory tests and it passed ok. After that I thought everything was good so I turned it off and screwed the memory expansion. Then I turned it ON and ran the memory test and got the error in Adr: 100000. So I unscrewed the memory expansion and removed it and reinstalled it without screwing it ON and it passed the tests. I am thinking that the issue is the connectors on the expansion get misaligned when i screw it. I am going to run some more tests tomorrow after work.


--Update--
  I just tested it again and still get the error in Address 100000. This sucks!! Esynthesist, how do you determine the IC# on the expansion board you stated for Bits 0-3 IC# 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48. Some of the ICs are missing on the expansion boards if i just use the ones that have chips in them i get bit 0=IC20, bit 1=IC24, ... bit 3=IC48? Am I on the right track?


  Esynthesis, do you have the service manual in a pdf? If you do, can you email it?

Thanks


Title: Re: EMAX II Memory problem
Post by: FmK@77 on May 09, 2012, 01:48:02 AM
Rtech,

First things first...

Removal of expansionboard en bootup. In the hidden menu, as mentioned earlier,

1: test BANK-RAM, because if one of the ic's is deffective in the BANK-RAM there is no way to test anything or the expansionboard properly.

IF test BANK-RAM is succesful than we can test further on...Let me know what comes out!

Frank


Title: Re: EMAX II Memory problem
Post by: rtech on May 09, 2012, 11:21:54 PM
I did run the test without the expansion board and i still got memory errors. I dont have the emax here at home i took it to my storage place. so the ram test should pass even if the memory size is incorrect, cause when I remove it i get a memory size error.



Title: Re: EMAX II Memory problem
Post by: FmK@77 on May 10, 2012, 01:25:05 AM
There are two tests for the emax II memory:

1: BANK-RAM, 64k chips
2: SOUND-RAM (G-RAM, 256k)

If number 1 fails, none of the tests will work or will be reliable, you'll get errors! How to check: MASTER 9,9 and enter 3629, and select 1. If it passes we'll continue to next check.

Frank


Title: Re: EMAX II Memory problem
Post by: rtech on May 10, 2012, 09:50:40 AM
Yeah the first one the BANK-RAM always passes. The SOUND-RAM always gives me errors. It worked a few times, but now it always gives me a memory size error and when I run the rests it fails.

I tried researching to see if I can find the Image of the chip that contains the memory configuration so i can revert it to a 2MB Emax II. I think I also need a IC that gets removed when you upgrade it to a 4MB or higher. Any ways I do not want to spend too much money on fixing it as they go for little money. I saw a guy selling a turbo with full memory for $200.



Title: Re: EMAX II Memory problem
Post by: FmK@77 on May 20, 2012, 02:43:18 PM
Well,

If I read your post of 09 februari 2012 the error was not so difficult to locate...

The ram problem is most likely located on your mainboard and NOT on your expansionboard. But I need to have a top photo of your expansionboard and your mainboard memory (and not someone elses) to know for sure...

Most likely 3 IC memorychips are not working properly. But since I don't know what you have swapped and what is still operational I can't tell right now...as I mentioned earlier, step by step.

I can try to help but you do need to give me info of today and not yesterday. Let me hear when you are ready to fire the Emax II up again and most willing to locate the problem.

Let's hope you placed the IC memorychips back the way they need to be replaced and not flipped over, that will cause serious damage to the main- or expansionboard!!! Example: Pin 1 of the IC must be connected on Pin 1 and NOT Pin 1 on Pin 11.


Frank


Title: Re: EMAX II Memory problem
Post by: FmK@77 on May 24, 2012, 07:01:20 AM
If someone else needs help with an error related problem with his Emax II let me know!

Frank


Title: Re: EMAX II Memory problem
Post by: rtech on July 26, 2012, 12:16:27 AM
I finally got my Emax II out of storage and trying to fix the issue with the memory. I reseated all the memory chips, but I always get the "Memory size ERROR". It always states the memory size at, 1 MB      0524244 (Samples), I think thats for the 1MB version, but my Emax II is a 4MB Model. When I run the GRAM Test it always passes. Im freaking stuck on what to do next, I have removed and seated the expansion board lover 20 times but it does not fix the issue. When I first got it from a friend it worked a few times when I reseated the Expansion board but that was it.

  Thanks for any input/suggestions.



Title: Re: EMAX II Memory problem
Post by: FmK@77 on March 13, 2013, 03:30:31 PM
Scrambled megs warning!

If your machine boots up for the 1st time with Memory size error don't go to the MASTER menu's or SETUP menu's. Just turn the Emax II off and disconnect every cable connected to it (inclusive the powercable). Wait 8 seconds...Reconnect with only the powercable and turn the Emax II on. If there is no problem with the EEPROM and nothing is saved into the EEPROM most likely the scrambled megs will be gone.

If you enter the MASTER menu or the SETUP menu the EEPROM with the Memory size error will be changed and saves permanently the status of the memory size. You'll end up with a machine that permanently has a memory size error. In that case you'll need to change the EEPROM through EPR ELECTRONICS or use an EEPROM burner with the correct bin.

Just wanted to let you all know.

Is there anybody who has used an adjust feature code with succes?

Kind regards,
Frank


Title: Re: EMAX II Memory problem
Post by: HS236589 on February 21, 2014, 03:34:54 PM
Hello!

I have the same problem; this message "WARNING! Sound MemorySize Error".
The sound is really weird.
The model of Emax II is 2212.

The Bank Ram test is ok.
The GRAM test gives me:
 
    IS: FFFF SB: 5678
    IC#?? Addr: 400000


I am desperate and i don't know how to solve this problem.
Please i need help,
HUGE THANKS IN ADVANCE,

Alex.


Title: Re: EMAX II Memory problem
Post by: HS236589 on February 23, 2014, 05:30:23 AM
Update:

after comversion Hex value to Binary value i found the bad IC.
Apparently it's IC# 48.

The new question is if it's possible to replace this defective element by another one?
the reference of this Ram is KM44C256AP-10   023 KOREA

Anyone know if there is an equivalent and if it's can be remplaced?

Thanks a lot