Amplifier switch off immediately when it switch on

make sure all your speaker connections and your phono lead connections are good and connected properly.also if you have the correct source(input for cd player etc.)pressed in,this could also be the correct speaker setting(a or b speakers)if your amplifier has a+b settings.check your speakers at the back to see if there are any switches,or if they are bi wirable(if they are bi wireable you will need two sets of wires running to both speakers from both speakers (a) and the (b) terminals,as if this was the case and you are only using 1 set of cables then only the treble may be working without any bass or the other way around.you could also look at your phono leadsby giving them a light twist to see if there are bad connections,if not if you can try and ask a friend or neighbour to try the speakers on their sound system and then you will know if its your amp or speakers that have the problem.i suspect it is your amp,if you have tried these things and got nowhere then you may have blown your output transisters and would be better off getting a new amplifier as it would cost too much to repair.only you know when the problem started and if it was by playing the amplifier too loud for too long then the volume dropped right down the it is probably the transisters that have been blown.hope this helps

It is not a transistor. It is an STR [Switching transistor Regulator]. Actually it is an IC, used at its power supply regulator section as main power switching regulator. Check this link to see its picture.

For more details type in this site name "Electro-help" (DO NOT copy and paste the site name from here. Doing so may lead you to wrong place) to search box of your search engine [not in the address bar of your browser], and press "Enter".

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Pull up older posts.

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A large amp like this likely has protection circuit (probably a relay) that doesn't connect the speakers until the amp is stable and balanced. You relly need the schematics for the amp.

Check the power transformer first to see if tou are getting power to the amplifier section. If you are getting power, your problem is probably the power transist is bad.

Unless you can test the circuits to determine the failure and check for the predriver stage for any failure do not try to change. You must be familiar with the junctions, the type of the transistors before you try, they could be a complimentary pair driver too. so if familiar buy the same rating, desolder from the pcb, care to see for the correct junction, insert the Base, collector , emitter leads carefully solder and test after rechecking once again. otherwise get help.. Good day

It sounds like the power transister for the amplifier has blown. Inside, it is usually the largest transister connected directly to a heat sink. It will require the ability to solder (and unsolder) in order to affect the repair. Look up the transister from its code inscribed on the case to find a replacement. Power transisters are usually not very expensive. You can go to this link to see what a typical power transistor looks like.
http://innovision-group.net/catalog/index.php?cPath=1_37

thank you for your help . I have already fixed the power supply I double checked the transisters and found three bad so I replaced all the power transisters and it is fine . thanks again bob

u will have to have all of the transister looked at ..when one goes bad ....let me say it is not just that one ...you can try radio shack...or do a web seach ...good luck

Chirping is usually a problem in 2 areas of this unit. 1st check 3 legged regultor on the right side of the chassis, also 2 small transisters and 2 resisters near and in front of the regulator. RCA has a kit for this problem, the second is check the horizontal output transister is on a separate heat sink along side of the Flyback Transformer, it shorts and pulls down the regulator power supply.

could possible a bad bias resister. easy enough checked with a meter for ohm. also check around the circuit one the side that gets hot see if the transisters farther in are getting hot as well of if they seem out of range on a meter. One thing I have found is if you look carefully at an amplifier stage it is pretty bisymetrical. so use measurements from one side to compare to the other. Sometimes this will give clues.