spacecat wrote:Im devastated, what could the problem be and how can it be fixed? CAN it be fixed? Is there a fuse in there that you could just change or is it possible i ran 230 volts through the whole motherboard and all? PLEASE help me before i get more suicidal Thanks in advance!
Not the first time I have seen this. ( here in Australia we run 240 volts )
Probably just the mains filter supply board fuse.
It's designed to blow before everything else to protect against these kind of mishaps.
Assuming that the correct fuse was present in the first instance... a simple fuse replacement should get the machine going again.
Here is a break down of fuse values, wiring layout and all to do with the power supply.
I've tried hard to make this as clear possible.
INFORMATION HERE TO BE USED WITH CAUTION.
DEATH OF SELF AND MPC BY DOING SOME THING WRONG WITH THIS INFO IS NOT MY RESPONSIBILITY

_____________________________________________________________
1: MAINS TRANSFORMER
The transformer will be marked according to your MPC3000's intended territory mains voltage designation.
These markings should fall within range of that indicated on your MPC3000's rear panel.
[C][A]
[J]
[E][V][B][S]
[E][V]
[B][S]
Colour codings for SECONDARY SIDE ( stepped down, unregulated AC ) wiring connected between
the transformer and POWER SUPPLY BOARD - L4012B507B socket P801:
BLACK & WHITE - unregulated AC feed to POWER SUPPLY BOARD - L4012B507B socket P801 and 5 V rectification
and regulation circuits.
ORANGE & ORANGE - unregulated AC feed to POWER SUPPLY BOARD - L4012B507B socket P801 and 12 V
rectification and regulation cicruits.
PURPLE - AGND.
______________________________________________________________
2: FILTER BOARD - L4012B507C
Resides on the primary mains side of the power transformer.
Is fuse protected.
The fuse ratings are critical.
The fuse location is marked on the board as "F1".
[C][A] - 1A 125V
[J] = 1A 250V
[E][V][B][S] - T1A 250V
Transformer critical connection socket.
Mains transformers maked [C][A] connect to socket P853
Mains transformers marked [J] connect to socket P853
Mains transformers marked [J][C][A] connect to socket P853
Mains transformers marked [E][V][B][S] connect to socket P854
Mains transformers marked [B][S] connect to socket P854
Mains transformers marked [E][V] connect to socket P853
Critical mains components other than fuses located on this board:
C851 0.068 uF (683) 275 VAC
C852 0.001 uF (102) 400 VAC
C853 0.001 uF (102) 400 VAC
C854 0.001 uF (102) 400 VAC
C855 0.001 uF (102) 400 VAC
C856 0.01 uF (103) 400 VAC
FL851 - LF4N 502
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3: POWER SUPPLY BOARD - L4012B507B
Resides on the secondary ( stepped down ) side of the mains transformer.
Is fuse protected.
The fuse ratings are critical.
The fuse locations are marked on this board as follows:
"F2"
[C][A] - 4A 125V
[J] - 4A 250V
[E][V][B][S] - T3.15A 250V
"F3"
[C][A] - 800MA 125V
[J] - 800MA 250V
[E][V][B][S] - T630MA 125V
"F4"
[C][A] - 800MA 125V
[J] - 800MA 250V
[E][V][B][S] - T630MA 125
Wire location W904 is the regulated power supply line output that supplies the MPC3000 circuit boards.
It connects at P1 on the main circuit board L4012A5010.
If you need to disconnect this line for any reason ( checking power supply output voltages is one I can think of ) then do it at the main circuit board end as this is where the socket is located.
PIN 1 = +5V
PIN 2 = GND
PIN 3 = -12V
PIN 4 = AGND
PIN 5 = +12V
PIN 6 = +5V
The power supply circuit is a fairly standard affair.
Unrectified, stepped down AC power is fed into Rectifiers D801 ( 5 V ) and D802 ( 12 V) and then into regulators IC801 ( 5 V )
and IC802/IC803 ( +12V/-12V ). Ancillary coupling, decoupling and smoothing capacitors are present also.
______________________________________________________________
I'll leave it up to you to trouble shoot the actual dead sections.
I would recommend checking the transformer primary and secondary lines for short or open circuits.
Inspect the FILTER board and POWER SUPPLY board for burnt and failed components.
REPLACE BURNT AND FAILED COMPONENTS.
Ensure that fuses are intact and the correct value for your machine's intended voltage operation.
Ensure that all sockets are correctly connected.
Check voltages with a meter etc.
Be patient when trouble shooting the power supply.
If you're not experienced at dealing with mains power stages then ... hands off an let some one else do it.
Rohan.