Broken Onkyo TX-7230 receiver

[tropix2006]

i have same problem, Can it be repaired???

[DrCassette]

@tropix2006

If you replace the amplifier chip, it might work again.

[yeoldeengineer]

v Oops, the T-4230 equivalent would obviously be the 4037...

[yeoldeengineer]

This unit should be from the 1985 model year. Going through the MESS that is Onkyo's int'l model numbers, it would appear that the respective cousin would be named TX-27; I managed to obtain service docs. Apparently these STKs belonged to an entire family, with 4863 and 4913 being ones rated for higher supplies.

Apart from the STK issue, it's not a bad unit. 4-gang FM frontend with AGC in this German model, 3 IF filters, pretty much what you got with a T-4230 (/T-4038) tuner.

[28019ab]

Unfortunately, lots of the big names in the 80s like Sony, Technics and Sanyo started using these STK amp chips. Often, protection was rather lacking. In this case there is a relay which will not open if the +40v or -40v rails are present at the spkr outputs. If someone hadn't bridged that fuse then this might have been fixable. It's amazing how stupid people can be, they don't understand that fuses blow for a REASON and that they protect the equipment. Shoving wire across them is a No-No!

[haz939]

Did you have the multimeter on the DC setting to test the speaker? It should read 0 volts

on DC if its not dead and a couple of volts on AC if its alive, its that correct?

[DrCassette]

@haz939

The meter was in the DC position.

[costellom5]

Seems to be a nice receiver.Doesn't it has those small potentiometers to adjust the output voltage?

[DrCassette]

@costellom5

The output voltage is there because the chip is blown.

[gmaildotcom]

There are quite a few STK4843's going for around $20 on ebay.

[mraiwa1000]

That's a bit cool with the display but then when you said it's not working I got sad. :(

This unit would be cool to have sines it has all the cool things if it worked

[mraiwa1000]

Yay, the 80's I love that year! :D

[viperfrank]

Nice video, one question though, why did you put the black box over the multimeter dial.

[DrCassette]

@viperfrank

It says my full name on there and I didn't notice that until I edited the video.

[powerlockit]

i like the style of it it looks in good condition from here 

[GanEdenVideo]

What's Rainy Day Productions?

[DrCassette]

@GanEdenVideo

That's a bit of a running gag. CoolDudeClem and CassetteMaster used this in the past too. Since it was raining, I thought it would fit.

[GanEdenVideo]

@DrCassette haha very good.

[TheMrmagnetophon]

What is the story with 2 houses, do you live in one and parents in the other?

[DrCassette]

@TheMrmagnetophon

No, we are all living in one house. The 'other house' used to by my grand aunt's house, and when she died, my mother got the house. We are currently using it only for storage, and I have my workshop and most of my audio/video collection over there.

[SAIL4323]

Why the black bar over the ohm meter dial?

[DrCassette]

@SAIL4323

It says my full name on there and I didn't notice that until I edited the video.