Technics as 423 Reciever No Sound

[Russell Flowers]

I have a technics receiver with no sound. The obvious stuff is all good. Fuse, correct buttons depressed, etc.

 

[WaynePflughaupt]

Any chance that after 35 years it just died of old age?

Regards,
Wayne A. Pflughaupt

 

[lovinthehd]

You sure one of those depressed buttons may have the tape monitor or similar, if it has such, that it may be set wrong? Did this work recently and you changed something to make it not work?

 

[TLS Guy]

I have a technics receiver with no sound. The obvious stuff is all good. Fuse, correct buttons depressed, etc.

Are you 100% sure that the tape monitor loop is not engaged?

If everything lights up it is very unusual for those old receivers to fail on both channels. Have you tried headphones to see if the preamp section works? If it does, then the phone plug is probably faulty and the phone plug is stuck in the position that disconnects the preamps from the power amps. This is a common problem on old receivers like that.

 

[Russell Flowers]

I purchased the reciver at an estate sale. Haven't tried head phones. But I'm beginning to think it had a bad stk module. Seems to be a common problem. I'm going th plug it in again and check to see if all the buttons are good. They seem to be. Then maybe a local sound shop can repair it. Or not?

 

[lovinthehd]

How much did you pay for it? Further money for repairs are probably not worth the expense IMO.

 

[Russell Flowers]

12 dollars.

 

[lovinthehd]

I wouldn't and repair places aren't as common as they once were. Future used gear recommendation---test it before you walk with it.

 

[TLS Guy]

12 dollars.

That receiver is new enough not to be serviceable. It had an stk IC dual amp module, not discrete transistor. Those ICs were easily fried by over driving. That IC is long NLA, and even the data sheet seems to have disappeared into the ether.

If it is not the headphone socket, you are out $12 plus a trip to the recycling center.

This chips have sold on eBay for around $40, but the sellers do not know if they work or not.

I would not gamble on one. If it not something simple you have junk. Get rid of it.

 

[M Code]

I have a technics receiver with no sound. The obvious stuff is all good. Fuse, correct buttons depressed, etc.

Many of the older stereo receivers had pre-out/main-in jacks...
If U have these, they need to be jumpered..

Just my $0.02...

 

[Russell Flowers]

Many of the older stereo receivers had pre-out/main-in jacks...
If U have these, they need to be jumpered..

Just my $0.02...

I'll check that.

 

[Russell Flowers]

That receiver is new enough not to be serviceable. It had an stk IC dual amp module, not discrete transistor. Those ICs were easily fried by over driving. That IC is long NLA, and even the data sheet seems to have disappeared into the ether.

If it is not the headphone socket, you are out $12 plus a trip to the recycling center.

This chips have sold on eBay for around $40, but the sellers do not know if they work or not.

I would not gamble on one. If it not something simple you have junk. Get rid of it.

 

[Russell Flowers]

I just wondering if both would go out. Seems unlikely.

 

[TLS Guy]

I just wondering if both would go out. Seems unlikely.

It has a dual power amp chip. Both amps are in the same IC, so over heating fries both.

There are no jumpers on that unit. If it is not the headphone jack, then it is the end of the road for that unit.

 

[Russell Flowers]

It should be the end of the road! Wish I could find replacment parts. The display and front panel very nice. Almost like new. I may hang on to it and try to find a parts unit.

 

[TLS Guy]

It should be the end of the road! Wish I could find replacment parts. The display and front panel very nice. Almost like new. I may hang on to it and try to find a parts unit.

Trouble is that will be the part the parts unit needs most likely.

To be honest, those were a low end unit. If you want a good older receiver, then go for an older one with discrete transistors and no ICs. The unit you have is not a nice unit at all.

 

[Russell Flowers]

Yes, I am looking at the Marantz and wondering. Is there a certain year they started using the module?

 

[M Code]

The majority of Marantz vintage receivers used discrete output devices. The IC power pack was used typically in the lower end budget receivers.

Just my $0.02..

 

[M Code]

Once U find a target Marantz receiver, post back the model # and we can provide more tech details. Note that we were the senior VP of product planning/marketing @ Marantz for 17 years.. In 1 of our home systems we still use a Marantz 2600 (400W x 2, Scope, quartz-lock) and its sounds incredible..

Just my $0.02...

 

[TLS Guy]

Yes, I am looking at the Marantz and wondering. Is there a certain year they started using the module?

The IC was invented in 1958, but they did not enter into common practice until about 1971.

I would say they large power amp ICs were not used until around 1984 and were in the 50 to 60 watt class.

I think any receiver before 1980 will not have power amps ICs, but may well have op amp ICs. Any receiver prior to 1970 will be tube or discrete transistor.