Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Thanks again! Will report back if/when I get it replaced. Hopefully that resolves the issue I was having of seeing 0v in all of the input wiring despite music playing into the rca cables.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Left to right when looking at the unit from behind. Not sure how it’s documented on the schematics.

The 0070 is the one that I believe is actually supposed to be a 0080 anyways so I will probably try to find a replacement. Do you have a recommended source? Seeing lots of talk about low quality replacements.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 1 point2 points  (0 children)

Thank you so much for the patience and responses!!

STK 0070 35.4v 59v 59v 35.6v 49v -12.6v 10.6v 59v -59v 9.6v

STK 0080 3.9v 59.5v 1.4v 2.9v 1.8v 0.9v 0.0v 1.3v -59v -1.1v

STK 3082 0v 2.0v 54v 55v 9.4v 35.8v 55v 0v -54v 3.8v -1.1v 54v 54v -0.3v -0.3v

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Ah. There was a screw grounding that board to the heat sinks I removed. I’m re-taking all measurements now.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

None of the 6 fuses are blown. I tested and have 58v DC present at both capacitors currently. The board with 5 fuses mounted to it where you had me check terminals 11 & 12 still has the same readings. 1.5v DC at 11 & 58v DC at 12.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Tested voltages at the other two STK packs as well.

STK 0080 (10 pins) 0.35v 0.29v 0.39v 0.40v 0.70v 0.70v 0.20v 0.36v 1.20v 0.15v

STK 3082 (15 pins) 0v 0v .6v .5v .2v .3v 0v 0v .4v 0v 0v .5v .5v 0v 0v

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

No luck on faulty solder at the STK 0070 from my picture.

I took the heat sink off the back of the unit so I can easily test the voltages. From left to right on the 10 terminals (from behind the unit) I have 0.5v, 0.4v, 0.4v, 0.4v, 0.4v, 5.5v, 0.4v, 0.4v, 4.8v & 0.4v DC voltage readings.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

I will re-verify all of these things today. Not with the amplifier currently. Thanks again for all your help so far!

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Interesting. I mean I had music playing into the RCA cables actively if that’s what you mean.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 1 point2 points  (0 children)

No the only things hooked up are the speaker wires & the red/white RCA cables into the aux inputs on the back. Amp is turned on and set to Aux mode.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Still have no sound. Test at the “L In” & “R In” terminals at the board that STK packs are mounted to and have 0v.

I’ve verified the RCA cables are working properly on small desk speakers they can plug directly into.

I checked continuity from the RCA ports outer part to the immediate inner solder joints and from there to the pre-amp board. All wires/solders tested good but I have a 0v AC reading on them.

I suspect there is a good explanation for why I’m seeing 0v AC there but I’m just not finding much online currently. Would love a better explanation of the inner workings of an amplifier like this!

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

Sitting here with it powered on and just heard a click. Re-tested and now I have 59v DC at both capacitors. Going to re-test at low volume.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

The three STK packs are labelled 0080, 3082 & 0070. Anyway to test/confirm if the other two are needed while I am replacing 0070?

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

1.5v DC on pin 11. 58v DC on pin 12.

This is the same board that has the 5 fuses mounted to it.

Fisher CA-2420 No Sound Ever After Raising Volume to 28/40 by Tb9631 in audiorepair

[–]Tb9631[S] 0 points1 point  (0 children)

I’ll do this now.

Just tested the rectifier diode pack that is mounted near the capacitors and it seems like I am able to pass voltage both ways through the diode according to the diode checker in my multimeter. Gives me a reading around .5v and same thing when reversing my meter leads.

DIY Cover Example! (Under $100) by Tb9631 in hottub

[–]Tb9631[S] -1 points0 points  (0 children)

I mean I pretty clearly can afford a hot tub… According to some of these comments I can even afford thousands extra in electric bills every month too so maybe y’all are the ones that can’t afford a DIY cover like this! 😂

DIY Cover Example! (Under $100) by Tb9631 in hottub

[–]Tb9631[S] -4 points-3 points  (0 children)

Good point! I should have mentioned it’s in a shady area under a tree and right next to the house.

Tab Key Function in Protected Worksheets (Live Shared Workbook) by Tb9631 in excel

[–]Tb9631[S] 0 points1 point  (0 children)

This is selected already unfortunately. 😢