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epr electronics are the emu repairer

i have replaced the psu before with a switchmode version from rs the voltages 12/-12/5v/0v

the psu is also used in the emax 1 and 2 there is a trimmer to adjust the 5v 4.6v is still with in range

emu did not make any of the psu they were sub contracted out to a korean firm called skynet and hence why there were no schematics as there were several versions of the same psu that used different methods of doing 110v and 220-240 switching

in later models some later e3 and emax2 used switchmode active sensing circuits the older versions need to have the switch on the back set

black boxes could be a bad scanner cpu chip common problem also on the emax1 and 2 the e3 and the emax1/2 all use the same button scanning chip its a masked rom rockwell 8bit cpu it interfaces with the main cpu and the usart if part of it fails you get the dreaded black boxes or no button scanning

epr did have spares

also who was the person you got the e3 from as there is a tinker from germany that bodges bits and recks traces who i had to repair a sp1200 because he tinkered with that

On 19 February 2015 at 14:22, NoëlBuhagiar laser@... [vintagesynthrepair] <vintagesynthrepair@yahoogroups.com> wrote:

Hi... have been given an Emulator III with a removed SCSI drive but owner said it worked loading OS from floppy.

When I checked it it did not work and LCD had black square characters. Checked all SMPS voltages and the +5V is low at 4.6V.

E-mu did not repair or supply schematic for the power supply. Are E-mu still in operation? Anyone has been here, before I dig in the power supply?

All caps seem to be ok although best to remove them to check to be sure.

Any help please, thanks,

cosmo

Vintage Synth Repair

Re: [vintagesynthrepair] E-mu Emulator III

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