Most power supplies used in modern computers are of the "ATX" variety, but if you aren't sure, take the old unit to the store with you to compare. The simplest rule of thumb is that the new unit should be exactly the same width as the old one. It's fine if the new unit is a bit longer, as long as it will still fit into your case. Do not hesitate to ask the salesperson or technician for help in identifying the correct unit to purchase. If the new unit has a large bottom mounted fan, the bottom rear bottom flange on some cases might get in the way. Add it to the case in the same place the old unit was, and use the mounting screws to fasten it down. The connections should be the same as they were before. It can require a bit of force to insert power connectors correctly, but if if you have to strain a great deal to push them in, you may be trying to connect them backward. It is very difficult to connect most Molex connectors improperly, but if you are determined (and strong) enough, it can be done. If you have to force too hard, try turning the connector around. If the CPU fan is stopped by a loose connector (or any other obstruction), the processor can be destroyed very quickly. You may wish to restrain unused cables to prevent them from getting tangled up in fans.  Power up the system and enjoy your new power supply. If your system doesn't start up correctly here, your failing power supply could have taken out the motherboard.
اشتر مزوّد طاقة جديد بنفس نوع مزوّد الطاقة القديم. أخرج مزوّد الطاقة الجديد من علبته وتأكد أن أبعاده مناسبة لجهاز الكمبيوتر. وصّل مكونات جهاز الكمبيوتر بمزود الطاقة الجديدة مع اتباع إجراءات منع التفريغ الكهربائي السليمة. تأكد أن الكابلات والموصلات غير المستخدمة لا تلمس مروحة المعالج أو أي مكونات متحركة أخرى. ضع براغ الغطاء في مكانها وثبتها بإحكام. وصّل كل الوصلات الخارجية في الجهة الخلفية من جهاز الكمبيوتر (كابل الطاقة والفأرة ولوحة المفاتيح والشاشة وكابل الشبكة والسماعات الخارجية وغير ذلك).