Harman Kardon Sub TS10

[Darrien]

Greetings! I bought this used subwoofer and there is a problem in the amplifier plate. Upon turning it on the LED only glows red for stand-by. The switch has an 'ON" as well as an ' Auto ' position and it makes no difference the LED stays red and never turns green. Has anyone ever had a problem like this and know what section of the amplifier board to begin trouble shooting in?
Here is the service manual on it : https://www.manualslib.com/manual/1265016/Harman-Kardon-Hkts-10.html?page=15#manual

Any help or suggestions would be greatly appreciated !

 

[WHONOES]

Have you tried putting a signal into it?

 

[Darrien]

Have you tried putting a signal into it?

Yes I have, makes no difference.

 

[73's de Edd]

Sir Darrien . . . . .

First of all, do you have incoming audio into the unit, as it is dependent upon that being detected in order for your RED/GREEN LED to switch to GREEN . . .if so detected ?
As is being circuit confirmed on page 20 of HK schematic traveling across the bottom to the LED at right bottom corner.

ADDENDA . . . .While researching and then poking up . . .prior entries were then showing up upon posting.

Move to schematic page 21, at almost central area of schematic and locate RWH-SH -124D as being RL1 relay.
Locate it on equipment and place finger on top of relay in order to use sense of feel.
Have the unit unplugged from AC power and then plug into power to see if the relay is then noted to click.
If not, keep finger in place and then then try the power switch to see if there is any reaction of the relay.
If no action, keep the system plugged in and then then use DC metering with negative lead to Neg speaker connection and positive lead to both terminals of the relay to see what the two voltages are being .
Standing by . . . .





73's de Edd
.....

 

[Darrien]

I'm not sure how to address you Sir, 73's de Edd or perhaps , Doctor! I first wish to express my gratitude for your response. I have worked the weekend and just got home to see your questions and suggestion. Indeed I do have an audio signal coming into the speaker. As to its being detected I don't know yet. What confuses me is that is that other subwoofers I have the LED changes from red to green upon changing the switch from auto to ' ON ' . By the LED becoming red shows that part of the amplifier board is working, I'm just unsure what section has failed. It is late here but as soon as I can I shall try what you have suggested. I believe it's a good place to start trouble shooting. Thank you for your time and help!

Darrien

 

[Darrien]

73's de Edd,
Sadly there is no reaction/click in the relay when power is applied. Checking for voltages I found zero at either terminal on the relay while a third post did have .36 volts. It would now appear something in the power supply part of the amplifier, yes? Thanks

Darrien