I have a unit with no power specs on it. But I have two different power supplies.
My issue is that if I use the one power supply the power supply gets flippin hot then the unit shuts off and I have to wait for the power supply to cool down.

The output is +5V - 2.4A

The other power supply that I have is +5V - 2.5A and I am too scared to use this PSU on my unit.

What could be the issue?

I'll give you the basics to help you understand what is going on.

The ratings on the power supply tell you how much power that it can provide. Thus, the supply rated 2.5A is actually more powerful (or capable) than the other one. The unit you are trying to power determines how much power is required, and the power supply will attempt to provide it.

The 2.4A supply can provide 5 X 2.4 or 12 watts, whereas the 2.5A supply can provide 5 X 2.5 or 12.5 watts. In reality, these are essentially the same.

Heat and power are related. Since the first supply is getting hot, that is a sign that the unit it is powering is drawing more than 2.4 amps. Since the supply is trying to do its job, but the unit is demanding more than it can provide, it gets hot and eventually shuts down.

My opinion is that the unit is drawing substantially more than 2.4 or even 2.5 amps, and that either power supply would have problems. Unless, of course, the 2.4A supply is defective. In this case, try the 2.5A supply and it should be fine. The only thing to watch out for is the polarity. Make sure that the + and - match between the two power supplies. (http://upload.wikimedia.org/wikipedia/commons/thumb/6/68/AC_adaptor_polarity.png/800px-AC_adaptor_polarity.png)

I hope this helps,
WallyH

Check for a manufactuer's lable on the unit you are trying to supply power to. It should have the power requirements posted on the bottom of the unit.

If that fails then do a web search using the unit's product name and model number.

It would also help if you tells us what you are trying to provide power for.

OK on the unit there is no manufacturer label or anything so I can't tell and also APC protect every thing. The unit is a Netbotz Wall bot 420

I Googled "Netbotz Wall bot 420" and found that the manufacturer is APC. I've found them to be really helpful when I called their tech support number. You might try that.

WallyH

I Googled "Netbotz Wall bot 420" and found that the manufacturer is APC. I've found them to be really helpful when I called their tech support number. You might try that.

WallyH
Weird... I know I didn't submit this twice!

I tried that but I am in South Africa they really don't like helping people here.

I found this part number at netbotz.com:
APC NetBotz Universal Power Supply NBAC0103

Then I found this link (http://www.thenerds.net/APC.APC_12Watt_AC_Adapter_for_Network_Appliances.N BAC0103.html) which finally offered some specs. It doesn't mention the discontinued 420, but it does say "universal", so I would think it would be close if not exactly the right thing.

So, it looks like your 2.4A supply is the right one. That it is getting hot may be an indication that the power supply or the unit itself is bad.

Good luck,
WallyH

Hey thanks for the help.
I have used another power supply 2.5A will see how that goes if not the client is going to have to buy a whole new unit. This must be one of the easiest products to support but what a mission when it comes to power