EMAX II Memory problem

[JAW]

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.

[rtech]

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

[esynthesist]

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

[rtech]

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

[FmK@77]

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

[rtech]

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.

[FmK@77]

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

[rtech]

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.

[FmK@77]

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

[FmK@77]

If someone else needs help with an error related problem with his Emax II let me know!

Frank

[rtech]

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.

[FmK@77]

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

[HS236589]

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.

[HS236589]

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

[EmuHarvester]

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.

Just posted this info to the General section, but seemed relevant to this thread as well...

E-mu Emax 2 Service Manual & Schematics:
https://drive.google.com/open?id=14sT9o-wmlTrosLFVLhZTSqHhpoeG319s

http://zine.r-massive.com/e-mu-emax-ii-memory-upgrade-unlocked/

Looks to be a new method for anyone that accidentally got themselves into a memory size error type situation. Or trying to get from 4MB or 8MB or whatever without the impossible to get memory upgrade disk.