8600 Power

Common to 195 and 295

8600 Power (Todd Products MAX-753-0512)
MAX 700/750 Series Datasheet
MAX-754 Series Datasheet (Replacement)

I do not have a complete list of Todd MAX-70x/75x and NMX- supply models. Others may be compatible, but I can't prove it. One plus is that the case fan is connected to leads on TB2, so you can swap a fan-cover onto a suitable replacement PSU...

750 watt universal power supply;  Optional redundant power supply.

Note: The PSU is Universal, but NOT Auto-Ranging. There is a set of spade terminals on the PSU's PCB, connected for 115v, open for 230v.

Replacements for MAX-753-0512
MAX-753-0512 ----> MAX-754-1205P Replacement has extra output and feature (P option) customer doesn't need to use.

MAX-754-1205P has an NSN of 6130-01-487-6246. Unfortunately, all I see is "RFQ" for price. Spidey sense makes me think that it isn't cheap...

Some Wild Guesses
Chances are the PCBs for the MAX 70x and 75x series are the same, but the components installed will change. That is why I'm looking to detail the inputs, configuration points, and outputs. All we need is close enough.

MAX Watts Output #1 Output #2 Output #3 Output #4
703-0512 700 +5V @ 100A +12V @ 12/20A -12V @ 10A
704-1205 700 +5V @ 100A +12V @ 12/20A -12V @ 10A 5.2V @ 2A
753-0512 750 +5V @ 120A +12V @ 12/20A -12V @ 10A
754-1205 750 +5V @ 120A +12V @ 12/20A -12V @ 10A 5.2V @ 2A
754-1212 750 +5V @ 120A +12V @ 12/20A -12V @ 10A 12V @ 2A
754-1224 750 +5V @ 120A +12V @ 12/20A -12V @ 10A +24V @ 2A
754-1252 750 +5V @ 120A +12V @ 12/20A -5.2V @ 10A 12V @ 2A

Note: The MAX-70x models Output #1 is +5V @ 100A, useable BUT will support less MCA adapters or hard drives or memory. Only a 100w difference, so if you are thoughtful, it should work.

Note: All Output #2 outputs have a sustained / peak rating of 12A / 20A. (peak) refers to a momentary surge, say for starting drives. Inrush current. So, +12v at 12A sustained, +12v at 20A for a short period...

Caution! MAX-754-1252 Output #3 is -5.2V @ 10A, NOT -12v!!! Will not function as a replacement...

MAX-753-0512 Fan
USTF922512LW  USTF9225 Series DC Brushless Fans

Model Volts Watts Amps RPM dB CFM
USTF922512LW 12VDC 0.84 0.07 2100 25.0 37.1

25.4mm thick, 92mm square

MAX-753-0512 Terminals

TB1 Terminals (AC Input)

Function 115 Vac 230 Vac Color
Input Select Short Open N/A
TB1 - (L) Line Line 1 Brown
TB1 - (N) Neutral Line 2 Blue
TB1 – (⏚) Ground Ground Green

Note: inputs TB1-3 use a Barrier strip with #6-32 screws on 3/8" centers

Lorenzo Mollicone says:
   When the inside power switch is closed, the main power is off. When the inside power switch is open, the computer powers up.  Without the switch connected, the machine powers on with the main power switch located above the power connector.

Input Select: pair of 1/4" spade terminals mounted on PCB, up from TB1 underneath the cover. For 115v, connect with a short wire with female spade connectors, or for 230v, leave the terminals bare (open).

Note: The Input Select jumper wire is a heavier gage. Checking.

TB2 Terminals (DC Output)

Function Location Notes Color
Output #1 Terminal +V Main Output Yellow?
Terminal -V Rtn (Common) Black?
Output #2 TB2-3 Yellow
TB2-4 Rtn (Common) Black
Output #3 TB2-5 Blue
TB2-4 Rtn (Common) Black
Output #4*(If provided) TB2-1 (+) N/C
TB2-2 (-) N/C

Note: Output #1 (-V and +V) is connected with Bus bars using #1/4-20 screws
Note: Outputs # 2-4 use a Barrier strip with #6-32 screws on 3/8” centers
Note: Cover fan connects to TB2. Fan Black goes to TB2-5, Fan Red goes to TB2-4.

J1 Terminals (Status and Control), That little plastic 4 position plug to the right of TB2. Pin numbering is reverse of TB2, Pin 1 on right, pin 4 on left. Go figure...

Function Location Notes Color
Remote Sense J1-1(+ S) Output #1 Sense Red
Remote Sense J1-2 (– S) Output #1 Sense Rtn Blue
AC Power Fail, or DC Power Good* J1-3 (PF) Reference to J1-2 N/A
Inhibit J1-4 (IH) Short to J1-2 Brown

J1 Connector AMP MTA type #640456-4 pin header (locking)

Note: Pin 3 (AC Fail or DC Good) is not connected (N/C). There is no wire to Pin 3. If you are replacing the original MAX-753-0512 with a PSU that has PF, leave the PF unconnected.

MAX-753 Series Specs:

OUTPUT Adjustability: User adjustable ±5% minimum.
Line & Load Reg: ±1% over AC range, 0-100% load change.
  Note: Output #1 requires min load of 10%.
Ripple & Noise: < 1% p-p or 100 mV, whichever is greater.
Remote Sense (Output #1): Corrects for 250 mV total line drop. Open sense lead protection.
Temperature Coefficient: 0.02% per degree C.
Stability: 0.1% over 8 hours after 30 minutes warm-up.
Transient Response (Output #1): Output v returns w/in 1% < 500 μs for 50% load change. Peak Transient Does not exceed 5%.
Overload: All outputs overload / short circuit protected. Auto recovery upon fault removal.
Overvoltage (Output #1): Protects load against power supply induced overvoltage.
Trip point factory set so output voltage cannot exceed 136% of nominal.
Remote Inhibit: Contact closure to negative sense line drops output power to nominal

Option "A", AC Auto-Range: Automatically selects 115 or 230 Vac range.
Option "F", Fan/Cover Assembly: Cover w/ fan needed for full ratings at 50°C ambient.
Option "G", DC Power Good: Not present on 295.
Option "P", AC Power Fail: Not present on 295.

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