ROCKFORD PRO 301 SP a bad right channel (burns TC11)

[josesony68]

Hi, I have passed this stage, rockford damaged, what happens is that the Q215 or TC11, came burnt, and try to change it, jump again, when more than half of the course entry level, then your temperature rises in a spectacular way to just frying, but if not exceed that tour, its operation is normal (at low volume, of course) the power, well, I suspect the U1 and U2, to test them any pin negative voltage has given me, any help? Thanks in advance.

[josesony68]

Originally Posted by josesony68

Hi, I have passed this stage, rockford damaged, what happens is that the Q215 or TC11, came burnt, and try to change it, jump again, when more than half of the course entry level, then your temperature rises in a spectacular way to just frying, very hot TC2, TC3, TC10 and TC11, but if I continue up the volume just burn the TC11, and after being burned, I have in the speaker output for that channel 29V! while the other channel is working well, any help? Thanks in advance.

please Perry are out there? can you help me?

[Perry Babin]

I read it but there's a bit of a language barrier. I couldn't quite understand what you wrote. Try writing it as you normally would and running it through a translator like the one google offers. Between your translation and the google translation, I may be able to understand.

When referring to the transistors, use the circuit board designations silkscreened on the circuit boards, not those on the insulators.

[josesony68]

Perry forgiveness, I said in the post, I have burned this stage, the Q215 was short and the audio output is 29V. I have twice changed, and what happens is that, when plugged everything is fine, but when trying to climb a little volume of audio input, heated very quickly Q115, Q119, Q219 and Q215, the latter is the burns, and the other channel is still running, I'm a little confused, any ideas?

[Perry Babin]

Did you check or reset the bias?

Does it heat up with no input?

Were the transistors soldered to the MEHSA insulators and were they clamped to the heatsink?

[josesony68]

Did you check the bias? What do you mean by that? transistors are good soldiers and when there is no input, do not heat anything.

[Perry Babin]

The bias current determines the idle current through the output transistors. You set it with the bias pots.
http://www.bcae1.com/temp/ausettingbias.swf

Did you solder the transistors back down to the MEHSA insulators?

If so, did you tin the backs of the transistors before doing so?

[josesony68]

agreement, Perry, I did not know that those two adjustable resistors were to regulate it, only seen them in such small stages, Now I have to go to work, this afternoon, I look and I tell you what happens, greetings. (yes, mosfet, are well soldered to the MEHSA, only one, which I removed).

[josesony68]

Sorry Perry, just to test the stage, adjusting the bias, and re-burn the Q215 (IRF540N) even putting the pot to a minimum, was still warming up fast, coming up the input volume, the other channel, however, is correct and until Monday, I can not buy the transistor, this electronics store does not open on Saturdays, so until Monday I can not go ... regards

[Perry Babin]

The IRF540N is not generally a good sub for the original IRF540. This may be the reason it's failing.