Pioneer SX-950 relay clicks on/off and no sound

Hello, I have a 950 with Issues, I am a Pioneer Nut since high school, and bought my first sx-950 new and have been hooked since.
This unit is very dusty inside and all knobs seem a bit tight, when I power the 950 on the relay clicks in about 10-15 seconds, and I will try fm or a cd
Then after a few seconds the relay starts clicking on/off and sound starts fizzling and pops to no sound at all Immediatly. and the lights flickered on the reciever once yesterday when this happened. I only had one channel of sound at all i think
When this happened. I bought this this way so i have no history on unit.
The large caps show no swell to them if this helps. I never had it powered on more then 2-3 minutes at any time, afraid of doing more damage. I will at least blow the dust out and deoxit the pots/switches thats about my skill level here. can dirty pots/switches cause the relay to act this way????
I would appreciate any direction. I also live around Bensenville Il, and if anyone knows a trusty tech for repoair I would also be greatful
Thanks and appreciate any input.

If the 950 had the integral power/speaker switch pot, I'd say more than likely it's the power switch, BUT IT DOESN'T. SO. Clean ALL the POTS and Switches on the Front and the back, The Pre-out/Main-in Jumpers and all RCA's. It's possible that a switch or pot is dirty and causing at least part of the problem. Clean it up and check back in.

Mark the Fixer I believe is close to you but he has at least a 6 month to a year backlog. Between him and Echowars they are the top TWO PIONEER guys here, and both are backed up enormously.

Get the manual http://www.akdatabase.org/AKview/displayimage.php?album=44&pos=100 and read the whole thing extensively. Learn the boards and where they are and get comfortable with it opened up (POWER OFF and cord disconnected). Get a Multimeter(with DIODE MODE and hFe test), a soldering iron, and the gear to go with the iron. Find some old PC boards and learn to solder and desolder on it. Learn about transistor's and their polarity and how to test them(hFe). There are some really good sticky threads in the General Audio Forums on how to do the above. Also check the DIY Forum too.

Larry

Thanks Larry, I gave the whole unit a deoxit bath . every pot/switch
and cleaned all the dust out, and still the relay clicks on/off over and over
sometimes 30-or 40 seconds between , but just keeps going on.
I will have to get educated quick to do as you suggest.
****Just discovered the Power supply board was hanging, one of the plastic post are missing, so I shoved it back in place still loose though.****
Maybe from shipping or someone was in here??? can this be possible cause??
I appreciate the response and will reply with any progress
Thanks again

NICKAVIVA1 said:

Thanks Larry, I gave the whole unit a deoxit bath . every pot/switch
and cleaned all the dust out, and still the relay clicks on/off over and over
sometimes 30-or 40 seconds between , but just keeps going on.
I will have to get educated quick to do as you suggest.
****Just discovered the Power supply board was hanging, one of the plastic post are missing, so I shoved it back in place still loose though.****
Maybe from shipping or someone was in here??? can this be possible cause??
I appreciate the response and will reply with any progress
Thanks again

Click to expand...

Most likely need a power supply and protect board rebuild at the minimum.Those plastic standoffs get brittle from the heat.Can get new ones from Mouser.

in Artie we trust

Artie Johnston, 561st Tactical Fighter Squadron?

The 950 is a great set to work on. No access issues. Not bad for the beginner. Power supplies run hot and on the ragged edge. Rebuild the power supply board with the list here on AK. Two hours’ work with de-soldering braid. It may cure the current problems, if not; a good start. “Lights flickered”

Power Supply Board

AWR-101: C10: 470uF 80v ACH-038: 647-UHE2A471MHD 470uF 100v
AWR-101: C11: 470uF 80v ACH-038: 647-UHE2A471MHD 470uF 100v
AWR-101: C12: 1000uF 35v ACH-039: 647-UPW1V102MHD 1000uf 35v
AWR-101: C13: 1000uF 25v CEA: 647-UPW1E102MHD 1000uF 25v
AWR-101: C14: 220uF 10v CEA: 647-UPW1V221MPD6 220uF 35v
AWR-101: C15: 470uF 63v CEA: 647-UPW1J471MHD6 470uF 63v
AWR-101: C16: 47uF 16v CEA: 647-UPW1V470MED 47uF 35v
AWR-101: C18: 47uF 50v CEA: 647-UPW1H470MED 47uF 50v
AWR-101: C19: 47uF 35v CEA: 647-UPW1V470MED 47uF 35v
AWR-101: C20: 100uF 63v CEA: 647-UPW1J101MPD6 100uF 63v
AWR-101: C21: 47uF 16v CEA: 647-UPW1V470MED 47uF 35v
AWR-101: C23: 100uF 35v CEA: 647-UPW1V101MPD 100uF 35v

Q1,8,9 (2SD313P-E)
512-KSC2073TU npn to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.66

Q2 (2SB507P-E)
512-KSA940TU
512-KSA940 pnp to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.62

Q3,7 (2SC1318)
512-KSC2383YTA
512-KSC2383OTA
512-KSC2383YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17

Q5 (2SC1318)
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40
512-KSC2690AYSTU

Q10 (2SC869-C)
512-KSC2383YTA
512-KSC2383OTA
512-KSC2383YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17

Q4,6 (2SA720)
512-KSA1013YBU to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.34
512-KSA1013OBU

All parts are in stock, "Mouser" Prices are more than listed: Sorry.

Hey ZEB. Go drink your Coffee 1st. You just replied to a 3 year old thread......

Which has been re-started HERE .

Hey! I work nights on expensive aircraft give me a break!!