Table of Contents
Amiga 2000 Power Notes
Power Supply
- Molex 2139 KK 3.96MM 14pin
- wire is 18ga 300v from power supply to mobo
- the standard rating is a 200W power supply
| Pin | Name | Wire Color | Notes |
|---|---|---|---|
| 1 | +5V | yellow | total +5V load is 20.5A |
| 2 | +5V | yellow | |
| 3 | +5V | yellow | |
| 4 | +5V | yellow | |
| 5 | GND1 | blue | |
| 6 | GND2 | blue | |
| 7 | GND3 | blue | |
| 8 | GND4 | blue | |
| 9 | +12V | orange | total +12V load is 8A |
| 10 | KEY | none | |
| 11 | -12V | red | total -12V load is .3A |
| 12 | +5V USER | green | |
| 13 | -5V | white | total -5V load is .3A |
| 14 | TICK | ||
| Volts | Amps |
|---|---|
| +5V | 20.50A |
| +12V | 8.00A |
| -5V | 0.30A |
| -12V | 0.30A |
- This system requires a 'tick' circuit which provides a 50/60Hz +/-10% reference signal to the video chipset or motherboard jumper J300.
- Would require a simple linear regulator circuit using a 7905 or equivalent, to generate -5V.
- At motherboard location J300, cover pins 2 and 3 with a jumper to internally generate TICK signal
- from AmigaKit adapter
- is this just their hardware adapter or all atx adapters?
Replacement Power Supplies
Sadly, you can't just substitute any ATX in for the A2000, see below. There is a small after market for replacement power supplies. See the A500 Power page for an easy Cisco swap.
Meanwell
Meanwell has become a standard for replacing power supplies for the 8 and 16 bit lines.
- MPQ-200B
- medical rated, high quality + high cost
- rated for 200W
- output
- +5V at 15A (vs 20.5A)
- +12V at 7A (vs 8A)
- -5V at 2A (vs .3A)
- -12V at 2A (vs .3A)
- RQ-125B
- only 125W!
- output
- +5V at 11A (vs 20.5A)
- +12V at 4.5A (vs 8A)
- -5V at 1A (vs .3A)
- -12V at .5A (vs .3A)
ATX PC Power Supply
Here's the standard PC power supply to compare to Amiga's needs. Nowadays, there is seldom a -5V power line. If you can find an old AT power supply you're almost guaranteed a -5V. Keep an eye out at yard sales and thrift stores. A quick and easy indicator is if a 5.25“ or 3.5” drive is in the PC. This usually means it is an old power supply so the -5V may be there.
| Pin | Name | Color | Description |
|---|---|---|---|
| 1 | 3.3V | Orange | +3.3 VDC |
| 2 | 3.3V | Orange | +3.3 VDC |
| 3 | COM | Black | Ground |
| 4 | 5V | Red | +5 VDC |
| 5 | COM | Black | Ground |
| 6 | 5V | Red | +5 VDC |
| 7 | COM | Black | Ground |
| 8 | PWR_OK | Gray | Power Ok is a status signal generated by the power supply to notify the computer that the DC operating voltages are within the ranges required for proper computer operation (+5 VDC when power is Ok) |
| 9 | 5VSB | Purple | +5 VDC Standby Voltage (max 10mA, max 2A in ATX 2.2 spec) |
| 10 | 12V | Yellow | +12 VDC |
| 11 | 12V | Yellow | +12 VDC |
| 12 | 3.3V | Orange | +3.3 VDC |
| 13 | 3.3V | Orange | |
| 14 | -12V | Blue | -12 VDC |
| 15 | COM | Black | Ground |
| 16 | /PS_ON | Green | Power Supply On (active low). Short this pin to GND to switch power supply ON, disconnect from GND to switch OFF. |
| 17 | COM | Black | Ground |
| 18 | COM | Black | Ground |
| 19 | COM | Black | Ground |
| 20 | -5V | White | -5 VDC (this is optional on newer ATX-2 supplies, it is for use with older AT class expansion cards and can be omitted on newer units) |
| 21 | +5V | Red | +5 VDC |
| 22 | +5V | Red | +5 VDC |
| 23 | +5V | Red | +5 VDC |
| 24 | COM | Black | Ground |
- /PSON activated by pressing and releasing the power button while the power supply is in standby mode. Activating /PSON connects the power supply's /PSON input to ground, thereby switching the power supply to full-on condition.
- 18 AWG is recommended for all wires except pin 11, which should be 22 AWG. For 300W configurations 16 AWG is recommended.
Last modified: le 2022/10/26 17:29