Ferguson stereo casseiver model # 3926 - year 1979

[kaps]

I recently acquired a Ferguson vintage model 3924 , made in Japan. Manufactured in 1979. Its in fairly decent condition but one channel has no output. I opened the set and found that one pair of D 726 transistors corresponding to the dead channel, was overheating imm after power on, zero volume and without any load.


What can be the reason. There are 2 pairs of Hitachi D 726 9E 2 power transistors for each channel.

Can someone please help. Its a nice collectible and I got it from my uncle who bought it originally. It has good sound but alas ! Only one channel working. I want to rectify the defect and keep it as a memorable.

Thanks.

 

[jerluwoo]

Most likely the transistors have shorted out. The 2SD726 are 80V 4A units so I would imagine the amps are rated 10-15 watt area. Lots of replacements out there if you cant find originals.

 

[kaps]

Thanks, can you please suggest some replacements as I feel Hitchis shall be difficult to get.

With the heating transistors soldered out the other ok channel also gets screwed up. On putting the shorted ones back in, the other channel works fine. Whats the possible fault. I did not see any blown fuse or any other fried component on the pcb in excess light and using a magnifying lens. On the back side also there was no shorted or dry solder connections.

I find that strange.

Thanks.

 

[JMFahey]

A magnifying lens is not enough.
You'll need a multimeter, some idea of how that amplifier works and start troubleshooting.

 

[kaps]

Agree. No short cut to success. LOL.