SX-680 no audio out

[avionic]

My Harbor Freight dmm does not seem to be up to the task of measuring anything other than voltage. I need to find a better meter...

Or replace the battery.

 

[avionic]

If so the resistor, R401 is bad.

And possibly C404 is shorted.

 

[avionic]

Resistors don't just go bad.

 

[Renov8r1]

R401: 2.4v, 51.7v.

 

[Renov8r1]

And possibly C404 is shorted.

I checked the voltage across C404 and watched it drain through the meter. I am not sure this is the correct way to test it..

 

[1MEGΩ]

I checked the voltage across C404 and watched it drain through the meter. I am not sure this is the correct way to test it..

R401 33 ohm resistor is open or went way up in value. Replace it and check the voltage at the collector of Q402 again. The filter cap is more than likely not shorted.

I checked the voltage across C404 and watched it drain through the meter. I am not sure this is the correct way to test it..

 

[avionic]

IMHO that resistor should be a flame proof safety type .
https://www.digikey.com/product-det...ronics-inc/CF14JT33R0/CF14JT33R0CT-ND/1830315

Set you back a whole dime plus shipping.

 

[avionic]

If it were me. Might as well make that shipping charge worthwhile......
Maybe pick up a few of those resistors as well. Just in case.

 

[Renov8r1]

Ok. I will post results.

 

[1MEGΩ]

Ok. I will post results.

You might want to clean all the switches and controls while you are at it. I am quite sure you will need to do that. Ebay has it, and no shipping charge.

https://www.ebay.com/itm/CAIG-DeoxI...426650?hash=item25c006465a:g:SiQAAOSwBt5ZFjfK

 

[Renov8r1]

I have the D5. What should I use to lube the tuner string wheels, etc.? I dont want to screw it up, but I think it should be easier to move.

You might want to clean all the switches and controls while you are at it. I am quite sure you will need to do that. Ebay has it, and no shipping charge.

https://www.ebay.com/itm/CAIG-DeoxI...426650?hash=item25c006465a:g:SiQAAOSwBt5ZFjfK

ve

 

[1MEGΩ]

It seems like maybe the main tuning shaft may be tight. Is there any end play (slack or slight in out movement) while holding the tuning knob and pulling and pushing it in and out? It should have about 1/32 to 1/16 inch in out free play.

 

[markthefixer]

no lube on the string.

Main tuning shaft is adjusted too tight, or the lube IN the shaft has petrified, so take the tuning shaft apart and clean / relube the shaft. Then be careful with the adjustments for nil rotary tension while not allowing free play in the shaft.

 

[SaturationPt]

x2 on R401.

I had a friend bring 2 SX-680s to repair before Christmas, same symptom, R401 was open on both units without any evidence of heat or other damage.

While in there I replaced the associated electrolytic capacitors, on one unit they were below spec, the other still in spec., not sure why these resistors failed.

 

[tarior]

See it all the time on SX-580 and 680. I think the resistor is a little under-spec'd.

 

[Renov8r1]

R401 was it! You guys rock! My total investment is now $20.10. It sounds great!