Is it safe to use this charging cable for my HP PC?

Question

Recently, my HP PC PSU and the cable had burnt up. I have tried looking for a charger with kind of the same voltage, power and amps.

So my previous chargers (HP) details are given:

INPUT: 
100-240V 
1.5 A
50-60 Hz

OUTPUT: 
19.5 V 
4.62 A
90 W MAX

Given below is what I found to be a new charger (ASUS) with following details:

INPUT:
100-240V
1.2 A 
50-60 Hz

OUTPUT:
20V 
4.5 A 
90 W MAX 

Now, here's the question, can I use the Lenovo charger for my HP PC?

Answer 1

In summary:

• If you can, get a new supply with the same manufacturer & model number
• Input voltage must suit your local supply
• Output voltage must match the equipment's requirements
• Output current / power must match, or be greater than the previous supply (or equipment's requirements)
• Check the polarity is correct and the connector fits

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DC power supplies are characterised in a few major ways:

• Input - Voltage / Current / Power
• Output - Voltage / Current / Power

Input

• Voltage - You just need to make sure that this suits your local power - e.g: UK is around 230v AC, US is around 110v AC. Many modern switched mode power supplies can tolerate a wide input voltage (e.g: 100-240v AC).
• Current / Power - these are largely irrelevant at this point, just make sure that you don't expect to draw high current (larger Amperage) though an undersized fuse / flex / socket.

Output

• Voltage - This is critically important and should match the device's requirements. If your previous supply had a specified 19.5v output, then you should get a replacement with a 19.5v output. 0.5v difference (20v) might "work", but it'll be operating in the tolerances rather than in the designed range. As the voltage difference increases, components may get hotter, have reduced life span, or stop working immediately.
• Current / Power - This figure specifies the power supply's upper limit - the new supply must provide the same or more power. Your original supply was able to deliver up to 4.62 A as its rated 19.5v output (which is ~90 W, P=IV), but this doesn't mean the device will consume this much current all the time. If your new supply is able to deliver more current / power, try not to get one that is too much larger.
• Connector - The most common DC connector is a "barrel jack", but there is a range of sizes (both outer diameter and pin) that can make things frustrating. There are a number of standards to help designers select the correct size connector for the voltage / current (and thus ensure that nothing too drastic goes wrong), but they are rarely adhered to. Also, larger manufacturers (e.g: Dell / HP / Lenovo) do funny things like put the pin on the "other" end, providing a third conductor, or use a square USB-shaped connector.

• Polarity - Something that is often missed is that the connector will have a polarity - e.g: the center of the barrel will be positive, and the outer surface will be negative. If you get a replacement power supply with the incorrect polarity, then you'll effectively be providing a negative voltage (-20v) instead, which will most likely cause permanent damage immediately. While center-positive is very common, it's not exclusive. Look for a symbol like these:

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I mentioned that oversizing the new supply is okay... consider Dell's range of laptops - ultra portable with long battery life, to portable workstations.

Many of them (especially in commercial setting) run from a supply that provides the same voltage and connector - but the less power hungry laptops are shipped with lower wattage adapters (e.g: 65W), while the more power hungry laptops are shipped with higher wattage adapters (e.g: 130W).

• Using a 65W adapter on a device designed for 130W will (in some cases) be "okay", but you'll find that the battery won't charge, or the performance will be significantly limited.
• Using the 130W adapter on a device designed for 65W will be fine, and there will be no issues.