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No sound from NHT sub amp

Have an NHT sa-3 sub amp. Few years old and went dead with a pop. Fuse did not blow so thought less likely output transistors? Big output capacitors all leaky. Pulled them and cleaned up the board. Replaced with new capacitors. Identical (2) and 2 that had same specs but slightly higher voltage rating (60's vs 50's other specs same). Powers up as before, but still no output. Have not gone over the rest of the output board. Nothing really looks fried. Is it very unlikely to be an output transistor without a blown fuse. How to proceed? I have a volt/ohm-meter. Can return it to NHT's repair co. but what fun is that. Plus they charge $150 plus the cost of shipping both ways and the only parts that cost anything are the Caps I already replaced. Thanks.Jeff Hartford

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Appreciate the direct "Ask Me". With reference to your post here;

Voltage checks are done with the power on whereas resistance/continuity check are performed with the power off and preferably the component out of circuit. The VOM would do.

You posted that the fuses have not blown and therefore you are assuming that the output transistors are not defective. Pls confirm this by performing a check on the base to collector to emitter of the output transistors. This page would illustrate how to check a transistor using a VOM. The output transistor once removed from the circuit (pls mark which goes to where), laying flat with the pins/feet pointing towards you would be base, collector and emitter. Although the real outputs if 2SA1302/2SC3281 would be larger.
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To be more specific and to confirm the above, would appreciate if you could post/share the schematic diagram.

May I also inform you that there are posts made by other members of the community (our co-experts, I am aware that you have provided solutions yourself in some other posts) that would be of additional help. ginko has posted the method/manner by which you could test the transistors and other components, while bunnydawg addressed the fuse not blowing. welcomejee has posted with an amp schematics of an NHT Subtwoi.There were however and I would expect more posts that are too general/generic to be of any real use to you. I would leave it to your discretion to filter through the flood of information.

As a site policy, once you rejected a solution or give it a "Thanks for Trying", that particular post/expert would no longer be viewable. For your benefit, may I suggest that you copy and paste the "workable solutions" to a document that you would have a record of previous or no longer viewable postings.


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