Short circuit problems? It may be the transformer

SOURCE: pyramid ps-15kx

Unplug the PS-15KX 120V AC cord !! Then take cover off. DO NOT plug the AC cord in unless you are used to working around a lethal voltage and current !!!!!!!!!!

If you can use a Multimeter, then measure resistance across each pair of the 3 leads of the output transistors. You will probably find fractions of an ohm across a pair of leads. One or both may be shorted. NOTE: Do not ever measure resistance in a powered up circuit, kiss meter bye-bye and maybe burn you too.

By putting more robust transistors in this supply, you may not gain much reliability. The supply is rated at a continuous current draw, which is less than the intermittent current they advertise. Read the spec's of any power supply you get and look for continuous current ability.

There are several better transistors that will substitute for the 2N3055. You will need to look at a transistor substitution book and check specs. The internet is great for this. I used to use all kinds of data books, and still have them! But looking up info on-line is nice. Motorola has some that will fit and have higher current and voltage ratings,

Get someone who is a ham or geek if you aren't sure about sticking your fingers in the power supply.

Be Careful, Work Safe, it is a factor of longer life.

SOURCE: Power supply seems to work fine until it has a

Note: I'm answering your post with the assumption that you plan on using this power supply with a computer. If this is not your intention, please disregard my solution attempt.

You likely already know this, but if you are powering a computer you're going to need a power supply with more wattage. I would recommend nothing less than a 350 watt power supply.

Follow this link to calculate how much power you need to run your computer: http://www.extreme.outervision.com/psucalculatorlite.jsp

If you're not ready to give up on your 270 watt power supply, then remove all PCI/PCI-E devices, USB ports, extra fans, non-boot hard drives, extra DVD/CD drives etc. one at a time until the computer powers up. Anything you can do to reduce the load on the power supply will help.

Good luck and thanks for using FixYa.

SOURCE: Re: Pyramid PS-36kx power supply buzzer sounded,red light came on

Hi! I saw your question, and maybe this will help. I also have a Texas Star 100w amp, and this same power supply. Even though the nominal draw for your equipment is way below the rated amp flow of the power supply, when you key up, and the output on the amp is at max, you are drawing the limit of your power supply! Try running this setup at a lower linear output. You don't need the full 100 watts to get out! 60-80 watts is aplenty! You should start at a low output, and slowly increase the output(while keyed up), untill the power supply starts to complain.(buzzer/light). This is what your limit will be. The only other cure, is a MUCH bigger power supply. Unfortunately, I cannot afford a 60-90 amp supply, so this is what I am forced to do to use the one we have. Also,keep your cb's output very low when using the linear amp. These amps are supposed to get a low signal from your radio, or the linear amp is overdriven. (noisy and unstable. Hope this helps you! 73's to you! jimsjinx