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

General Category => EIII XP Technical Issues / Tips => Topic started by: edude on July 04, 2017, 02:47:18 PM



Title: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 04, 2017, 02:47:18 PM
i replaced the screen with an oled, and it works fine

however i made a few booboos (i lightly accidentally scratched a few traces) or maybe shorted something because now it will only recognize 1MB of RAM

also i can't save the os onto floppy, it returns errors when it tries to write

also, some sounds i did manage to load were corrupted and were digital noise. only a few though, otherwise it is ok

also, where before if there was no scsi termination i could not get past the startup screen, now it will flash the error for a split second then go on to load the os

i think i messed this eiiixp up : / none of these errors happened before i replaced the screen

any ideas? this was my backup and i would hate to sell it


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 04, 2017, 03:10:18 PM
i just noticed this though, under where the inverter was

i moved the part a bit when i desoldered it and it seems to have scratched the trace. this trace goes left and to the ram section btw



Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 04, 2017, 05:38:22 PM
a close up


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: Wolfram on July 05, 2017, 02:46:56 AM
Nice cut. ;-)
Remove carefully the lacquer and put a small drop solder on it.
You can measure functionality from the end to end of the trace.


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 05, 2017, 03:56:06 AM
thanks : )

i cleaned the trace and it is not cut. the inverter had caused some residue/corrosion but it is still intact

now it won't even boot up, first it shows the preset definition light for a few seconds then just flashes all lights and no screen


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 06, 2017, 05:52:01 AM
dag namnit, flew too close to the e-mu on wings of noobishness

anybody know what the preset definition diagnostic light means?


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: Wolfram on July 06, 2017, 08:13:47 AM
Verify the cable connection to the panel board.
Measure the connection from end to end.
Be sure pin 1 is connected to pin 1.


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 08, 2017, 07:19:50 AM
i test using a multimeter yes?


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: Wolfram on July 08, 2017, 09:05:13 AM
yes, turn of the EIII set the multimeter to Continuity beeper and check the connection from end to end.


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 09, 2017, 10:50:46 AM
isn't that just checking the cable though? checking pin 1 on panel and pin 1 on main board with cable between only checks the cable for continuity yes?


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on July 11, 2017, 03:33:03 PM
i checked as many traces as i could on the panel and they are ok, but still not sure what you say


Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: obsoletemachines on July 27, 2017, 02:51:25 AM
hi,
i don't think there is damage to the trace from the photos you sent...the traces run quite deep in this pcb and are not just 'stencilled' on to the PCB.

I think you need to go back to basics and test the power rails first.. what are you getting there.

If the power is ok then something is probably shorting the RAM circuitry - did you drop anything into the board?  Re-seat the ram chips... they may be slightly dislodged. But first as i say check the rails.



Title: Re: Replaced The Screen, Now Only 1MB RAM is Recognized : /
Post by: edude on August 09, 2017, 11:38:37 AM
hi,
i don't think there is damage to the trace from the photos you sent...the traces run quite deep in this pcb and are not just 'stencilled' on to the PCB.

I think you need to go back to basics and test the power rails first.. what are you getting there.

If the power is ok then something is probably shorting the RAM circuitry - did you drop anything into the board?  Re-seat the ram chips... they may be slightly dislodged. But first as i say check the rails.



thanks  :)

i could try soldering the inverter back on and swapping the front panel with one from another eiiix just to test, although since the problems are with ram among other things it may be the main board as you say? the ram chips are soldered on btw i believe

i am not experienced to do anything much besides check the rails, but by rails do you mean the main power rails going to the drives? i'm not sure how to check any other than those