Emulator II: Supply Rails and PSU Harness Colour Codes

[HideawayStudio]

UPDATED:

                For those more technically minded who want to fault find or even look into replacing their PSUs with something a little more modern/reliable here are some details on the EII's supply rails to the main PCB assembly connectors and drives.

There are two types of PSU wiring harness found in EIIs which connect to the 8 pin PSU output header J101.  One is identified by only single wires going to each crimp on the output header connector and the other by there being two wires ie. the harness is daisychained to the same header using an IDC header connector.  The pinout is the same BUT the colour code is slightly different and on the single wire crimp version there is no orange wire in position 7.

J101 pin: Colour:    O/P Voltage:   Usage:               Notes:
=============================================================
1             Red        +13.4 volts         Analog +ve rail Linear post regulated - low current
2             Yellow       +5 volts          Digital 5V          Switch Mode - High Current - CPU/Logic
3             Yellow       +5 volts          Digital 5V          Switch Mode - High Current - CPU/Logic
4             Green         0 volts           Return
5             Green         0 volts           Return
6       Blue or Purple   0 volts            Return
7*          Orange    +12 volts           Digital 12V        Switch Mode - High Current - Disks
8              Black      -15 volts          Analog -ve rail   Linear post regulated - low current

* Note:  This wire is not present on single crimp harness connectors.
    
I have yet to determine the supply currents but I suspect the analog rails are <2 amps and the 5 volt rail at least 15 amps!!  The 12 volt rail will be fairly hefty too.

Both Green and Blue/Purple returns appear to star earth in supply and are very much connected together as far as I can see in the PSU schematic.

A combination of a 12/5V 150W switcher and a +/-15V linear PSU chassis would probably work well in this application.   I will post more when I get a chance to poke around again in my EII.

BE VERY CAREFUL OPERATING EII WITH THE TOP CASING REMOVED - THIS PSU BITES ALONG WITH THE BACK OF THE IEC SOCKET, SUPPLY SELECTOR SWITCH AND FUSE HOLDER.   THE PSU ITSELF IS FULL OF HIGH VOLTAGES AND PRODUCES A SIGNIFICANT OUTPUT CURRENT WHICH, IF SHORT CIRCUITED, COULD CAUSE SERIOUS DAMAGE TO YOUR SAMPLER - OR YOU!!

THE ABOVE NEEDS VERIFICATION - BY OTHER OWNERS!!

[Chaztech]

Thanks Hideaway! good information!

[dr.c]

Sorry, but it would have been great if you could have given the pin numbers with the corresponding colors and the voltages. For example, if one gets the connector dissassembled, its impossible to rewire it with these infos. For example, there is an empty place, and as well, two yellow and two green connections.
Does the connector you have correspond to the picture below ? It seems that there are TWO KINDS of wiring !

Thanks in advance

[HideawayStudio]

Sorry, but it would have been great if you could have given the pin numbers with the corresponding colors and the voltages. For example, if one gets the connector dissassembled, its impossible to rewire it with these infos. For example, there is an empty place, and as well, two yellow and two green connections.
Does the connector you have correspond to the picture below ? It seems that there are TWO KINDS of wiring !

Thanks in advance

Very good point Dr.C - yes I've gotten the impression there are two PSU's and harnesses for a while now.   Between us I think we need to determine the changeover date/serial number range for each and how to identify them.

My EII is an earlier EII ie. not a an EII+.   Unfortunately my S/N has worn off the label with age but I will checkup the manufacture date.

I will take a picture of my PSU harness connector similar to yours.   The concern is that the colour codes are different too.   It is highly unlikely that the voltages are different - just the connectors and colour codes.  

I have modified the original post with details for both variants - I would feel happier though if more owners could verify this table.

[Chaztech]

Hi Dr.C, Hideaway,

I have 5 EII's and the wiring is the same as your picture.
On a working unit i Measured
red 13.13volts  
yellow +5.0V
greens ground
empty space +14volt positive
the black -14.00volts

Blue line gave me nothing could be AC maybe?

I will check the schematics i have and confirm.

remember these color codes are opposite a typical 3.1/4 floppy
red and yellow are reversed! i fried a floppy before i realized it.
the mounting kit had a power adapter plug for the 3.25 floppy
 the power positions are incorrect for the emulator
but this can be easily remedied by swapping the pins on the adapter plug.

regards!

[Zomnius]

5 eII's ??

We like to see some pictures of that don't we?

[Elmbeatz]

yes!

[Zomnius]

pics please........5x EII - heaven!

[dr.c]

The buffer is full, I cannot send docs.

sent me your email adress at :

dr.c@keyboardsrecording.fr

I will mail the docs

[Drone]

Hi Dr.C, Hideaway,

I have 5 EII's and the wiring is the same as your picture.

regards!

Piks Please !

[erwinIII]

does all the info about wiring hideaway posts also exist for the EIII keyboard ?

[ryansupak]

Has anyone successfully replaced the PSU in their unit?

rs

[FairlightCMI]

Hideaway...thanks for the great info.

Does anyone know if the 2 types of EII psu's are interchangeable? I have 2 EIIs with one of each type of PSU. (One with the 2 cables per pin at J101 and one with a single per pin)

I would like to swap them out for troubleshooting purposes. Can that be done without problems?

[DARKSHINE]

I make the test of tension of power supply
If I test it to the outside of the box
I am forced to disconnect the two connectors Voltage 110/220
What is the voltage in this case the original that I must provide 220v/110v
I think my Emulator II + original EUROPEAN

[DARKSHINE]

Connector which are connected to Selector control voltage 110v/220v