Hitachi HA-250

[cjackson]

I have just acquired one of these for free, got it home and it powers up but there is no sound.

I have had the lid off and cleaned it out and have made sure the glass fuse is fine.

Anybody got any ideas ???

 

[matthewpiano]

Is there a protection circuit on the amp and, if so, does the relay click in after power up?

 

[cjackson]

I've no idea, when the amp is powered on there is no noise, the power LED illuminates but thats it. I also tried plugging a pair of headphones in and that also did not work.

Cannot find a manual for this thing on the net.

I dont know what to do with it - it'd be better than my current amp if I could get the damn thing working!!!

 

[cjackson]

I think I have found the relay, it's in a transparent plastic cube, with a huge spring on top but it's all enclosed into this plastic tube. When the amp powers nothing seems to move or click ... could this be the problem ??

 

[Anonymous]

Hi know this thread is a bit old but is the only way i could find to contact you.

I too have an Hitachi HA-250. Had it for about 10 years and worked perfectly everyday until last week when it just stopped. Sounds like the exact same problem you had, it still powers on but does nothing. I noticed that the relay 'click' after turning on the power no longer happens and was just wondering if you managed to fix yours.

Any help would be much appreciated. Thanks

 

[Anonymous]

there is a thyristor that is 'on' holding the + zener votage off, ive removed the thyristor as there is no fault with the amp, its a small transistor package to the left of the 2 regulator transistors (TO220), it removes the +14v stopping the relay being turned on, this was the fault on one ive just repaired-no gtee its the problem with others