Dell OptiPlex 9020 SFF & Precision Workstation Power Supply Replacement Guide – 255W AC255ES-00 Compatibility
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Product link: https://nadalan-power.com/products/255w-dell-optiplex-9020-sff-power-supply
Is Your Dell OptiPlex SFF or Precision Workstation Having Power Issues? Here‘s Your 255W Replacement Guide
If you own a Dell OptiPlex SFF (9020, 7020, 3020) desktop or a Dell Precision workstation (XE2, T7100) and are experiencing power failures, random shutdowns, or simply need a spare power supply, you’ve come to the right place.
Dell uses specific power supply designs for their OptiPlex SFF and Precision workstation lines. Finding the correct replacement can be challenging because standard off-the-shelf PSUs often won‘t have the right connectors or physical size.
This guide will help you quickly identify if the 255W AC255ES-00 Power Supply is the right match for your Dell computer.
Quick Compatibility Check
This 255W power supply is specifically designed for the following Dell models:
Dell OptiPlex SFF Series:
| Series | Compatible Models |
| Dell OptiPlex 9020 | 9020 SFF (Small Form Factor) |
| Dell OptiPlex 7020 | 7020 SFF (Small Form Factor) |
| Dell OptiPlex 3020 | 3020 SFF (Small Form Factor) |
Dell Precision Workstation Series:
| Series | Compatible Models |
| Dell Precision XE2 | XE2 Workstation |
| Dell Precision T7100 | T7100 Workstation |
⚠️ Important: This power supply is designed for Dell SFF (Small Form Factor) desktops and Precision workstations. Please verify your computer model before ordering.
Compatible Power Supply Models
This power supply replaces the following Dell power supply models:
| Model Number | Compatible? |
| AC255ES-00 | ✅ Yes (main model) |
| AC255ES-01 | ✅ Yes |
| L255AS-00 | ✅ Yes |
| L255ES-00 | ✅ Yes |
| H255AS-00 | ✅ Yes |
| H255ES-00 | ✅ Yes |
| H255ES-01 | ✅ Yes |
| HU255AS-00 | ✅ Yes |
| HU255ES-00 | ✅ Yes |
| HU255ES-01 | ✅ Yes |
| D255ES-00 | ✅ Yes |
| D255AS-00 | ✅ Yes |
| B255ES-01 | ✅ Yes |
Compatible Part Numbers:
| Part Number | Compatible? |
| YH9D7 | ✅ Yes |
| V9MVK | ✅ Yes |
| FP16X | ✅ Yes |
| NT1XP | ✅ Yes |
| 3XRJ0 | ✅ Yes |
| VX372 | ✅ Yes |
| R7PPW | ✅ Yes |
| T4GWM | ✅ Yes |
💡 Tip: Simply remove your old power supply and check the sticker on top. If you see any of the model numbers or part numbers listed above, this replacement will work perfectly.
Key Specifications at a Glance
| Specification | Detail |
| Power Output | 255W |
| Dimensions (L×W×H) | 240 × 72 × 62 mm |
| Form Factor | Dell OptiPlex SFF / Precision Workstation |
| Input Voltage | 100-240V (Universal) |
| Quality | Brand new, high-quality, stable and silent |
This 255W output provides reliable power for Dell‘s SFF business desktops and Precision workstations, ensuring stable performance for demanding tasks.
Connector Configuration – The Most Important Check
| Interface Type | Connector | Quantity |
| Motherboard Main Power | 8-pin | 1 |
| CPU Power | 4-pin | 1 |
⚠️ Note: Please verify the 8-pin connector type matches your motherboard. Dell SFF and Precision workstations use specific proprietary connectors that differ from standard ATX.
Physical Size – Measure Before You Order
Even if the model number matches, it‘s always a good idea to check the size.
| Dimension | Measurement |
| Length | 240 mm |
| Width | 72 mm |
| Height | 62 mm |
This specific size is designed to fit perfectly inside Dell OptiPlex SFF (9020, 7020, 3020) and Precision (XE2, T7100) chassis.
Why Choose This 255W Replacement Power Supply?
| Feature | Benefit |
| Wide Compatibility | Works with OptiPlex 9020/7020/3020 SFF and Precision XE2/T7100 |
| Direct Replacement | No adapter or modification needed – works right out of the box |
| Universal Input | 100-240V – works worldwide (plug adapter may be needed) |
| Multiple Model Support | Replaces 13+ different Dell model numbers |
| 8-pin + 4-pin Connectors | Matches Dell SFF and Precision specification |
| Quiet & Stable | Reliable quality with silent operation |
| Efficient & Energy Saving | High efficiency design saves power |
| Brand New | Not refurbished – guaranteed reliability |
| 1-Year Warranty | Protected by Nadalan‘s 1-year return/exchange policy |
| Fast Global Shipping | Air freight to most countries in approximately 10 days |
Compatibility Note:
This power supply is compatible with multiple Dell models. As long as:
- Size is appropriate – fits your Dell SFF or Precision chassis
- Power is suitable – 255W meets your system‘s requirement
- Interface is compatible – 8-pin + 4-pin connectors match your motherboard
Please verify all three conditions before purchasing. This is a brand new, high-quality unit – stable, silent, efficient, energy-saving, and fully guaranteed.
Installation Tips
- Power down and unplug your Dell OptiPlex or Precision completely.
- Open the case – Dell SFF cases typically have a latch or thumbscrew on the back.
- Disconnect cables from the old power supply – note where each connector goes (8-pin main, 4-pin CPU).
- Take a photo of the connector layout before disconnecting – this helps during reinstallation.
- Remove the old PSU – usually held by 3-4 screws on the back of the case.
- Install the new PSU – secure with screws, then reconnect all cables following your photo.
- Test before closing – power on to ensure the system boots properly.
Frequently Asked Questions
Q1: What Dell models is this 255W power supply compatible with?
Compatible with Dell OptiPlex 9020 SFF, 7020 SFF, 3020 SFF, and Dell Precision XE2, T7100 workstations.
Q2: What are the compatible power supply model numbers?
AC255ES-00, AC255ES-01, L255AS-00, L255ES-00, H255AS-00, H255ES-00, H255ES-01, HU255AS-00, HU255ES-00, HU255ES-01, D255ES-00, D255AS-00, B255ES-01.
Q3: What are the compatible part numbers?
YH9D7, V9MVK, FP16X, NT1XP, 3XRJ0, VX372, R7PPW, T4GWM.
Q4: What connectors does this power supply have?
It includes: 1x 8-pin motherboard interface and 1x 4-pin CPU interface.
Q5: What are the physical dimensions?
240mm × 72mm × 62mm.
Q6: Will this work with Dell OptiPlex 9020 Mini Tower (MT)?
No. This is specifically designed for SFF (Small Form Factor) models, not Mini Tower.
Q7: Is this a genuine Dell power supply?
This is a high-quality compatible replacement that meets or exceeds OEM specifications – brand new, stable, silent, efficient, and fully guaranteed.
Q8: Can I use this power supply on other Dell models?
It is designed for OptiPlex 9020/7020/3020 SFF and Precision XE2/T7100. For other models, please check your original power supply model number against our compatibility list.
Q9: What is the warranty period?
Nadalan offers a 1-year warranty on this power supply.
Q10: How long does shipping take?
Approximately 10 days by air freight. Tax and duty included for most countries.
Still Not Sure? Contact Us
If you‘ve checked the model numbers, sizes, and connectors but still aren’t 100% sure, don‘t guess. Send us a photo of your original power supply’s label and connectors, and we will confirm compatibility for you.
Contact Nadalan:
- Email: gc_ds@sina.com
- Phone / WhatsApp: +0086 18062682902
Order today and get your Dell OptiPlex or Precision workstation back up and running with reliable, efficient power.