G-9700 Sansui Receiver phono stage problem

amplifiers, receivers and loudspeakers
Post Reply
vmd254
member
member
Posts: 32
Joined: 22 Dec 2013 17:25

G-9700 Sansui Receiver phono stage problem

Post by vmd254 » 12 Jul 2019 22:55

I purchased a Sansui G-9700 receiver couple months ago, under warranty, as it had been gone through and checked and anything not up to specification was repaired or replaced. When I got it right away the phonostage was giving intermittent problems. Started out that sometimes when switched from another source to the phono the Left channel would not put our more that one bar (.05 W) power level. Quickly became that the Left Channel was always like this on phono - all other sources working fine.
The fine gentleman I purchased it form is offering full refund, or I can get it back after the phono stage is repaired and try it out for a period of time b4 agreeing to the purchase.
Question - what am I dealing with here? Is there a partial "fix" that may be done yet leave me at risk for having to replace the entire circuitry later?
Appreciate any input and advice.

ricksbsa
member
member
United States of America
Posts: 57
Joined: 23 Jun 2019 20:47

Re: G-9700 Sansui Receiver phono stage problem

Post by ricksbsa » 12 Jul 2019 23:30

Possibly just a dirty selector switch. Have you tried phono 2?

Alec124c41
vinyl engineer
vinyl engineer
Canada
Posts: 22983
Joined: 28 Oct 2002 03:24
Location: North of Toronto, Canada

Re: G-9700 Sansui Receiver phono stage problem

Post by Alec124c41 » 13 Jul 2019 04:36

Try contact/control cleaner in the selector switch.
Another thing I have encountered in a receiver is the pressure of attaching and detaching the RCA plugs putting enough pressure on the connector to have cracked a solder joint on the internal PC board.

Cheers,
Alec

vmd254
member
member
Posts: 32
Joined: 22 Dec 2013 17:25

Re: G-9700 Sansui Receiver phono stage problem

Post by vmd254 » 15 Jul 2019 14:57

Thanks for replies. I did try phono 2 and the same thing happened, switched the speakers L & R and still happened. All other sources no problems. The person that did the repairs initially said it is something in the circuitry. Just wondered if anyone heard of this happening before to a phono stage or a Sansui phono stage. Could be the cracked solder joint, never considered that.

ricksbsa
member
member
United States of America
Posts: 57
Joined: 23 Jun 2019 20:47

Re: G-9700 Sansui Receiver phono stage problem

Post by ricksbsa » 15 Jul 2019 17:38

Did you try aux, tape 1, and tape 2 inputs with the same results?

lenjack
long player
long player
Posts: 1647
Joined: 23 Jun 2017 02:11
Location: Liverpool,PA

Re: G-9700 Sansui Receiver phono stage problem

Post by lenjack » 15 Jul 2019 19:00

If contact cleaner doesn't help, I'd go for the refund.

tcolegrove
senior member
senior member
United States of America
Posts: 348
Joined: 10 Apr 2013 17:26
Location: Menomonee Falls, WI
Contact:

Re: G-9700 Sansui Receiver phono stage problem

Post by tcolegrove » 15 Jul 2019 19:23

Call me ultra-cautious (Paranoid?) but I wouldn't do anything to it myself, such as contact cleaner. The item is under warranty and I'd be reluctant to put myself in a position of the seller saying that I'd messed with it and therefore voided the warranty. Just give them another chance to make it right.

ricksbsa
member
member
United States of America
Posts: 57
Joined: 23 Jun 2019 20:47

Re: G-9700 Sansui Receiver phono stage problem

Post by ricksbsa » 15 Jul 2019 19:55

You can't clean the rotary switch by just pulling the knob off anyway. The switch is soldered to a board, which must be unscrewed from the frame and flipped over to access it. All the pots and switches should be thoroughly cleaned and lubed in these Sansui Gs when serviced, they are known for their ability to attract oxidation gremlins.

Post Reply