SX-1080 and SX-850 Same Tuner Problem

[Soundking]

I have a SX-1080 and a SX-850.

Both have the same tuner problem.
And one, the SX-850 pop's in the speakers after it heats up. Also the protection relay kicks in.

The tuner problems is hard to explain but here we go.

1: very low sensertivity.
2: Tuner just sounds like it's paded and distorted.

I am thing alignment.
But what is the likely hood of both need it.:scratch2:

Any help would be aprecated,

 

[EchoWars]

First step to solving a problem is to identify it in as much detail as you can. To me, it sounds like multiple issues. Consider talking to this man: http://www.radioxtuners.com/

 

[Soundking]

I have a SX-1080 and a SX-850.

Both have the same tuner problem.
And one, the SX-850 pop's in the speakers after it heats up. Also the protection relay kicks in.

The tuner problems is hard to explain but here we go.

1: very low sensertivity.
2: Tuner just sounds like it's paded and distorted.

I am thing alignment.
But what is the likely hood of both need it.:scratch2:

Any help would be aprecated,

OK,,,,,, after doing an extensive search on this forum I have found some GREAT infomation.

First off, the two tuners have different problems. Not like I first thought.
The SX-850 distorts after it warms up. Could be many thing. The SX1080 can not be tuned to center and the FM and Stereo light does not come on. From what I have read this could be due to a bad IC PA1001-A or PA1002-A.

It looks like I have alot of work to do.:tears:

The PA1001-A and PA1002A went the way of the DOE-DOE Bird.
I can maybe get a PA1001 and a PA1002 for the SX-1080.

I want to thank this forum for it great resource.:thmbsp:

P.S. Anyone know of an Expert Pioneer Repair Shop On Long Island?:sigh:

 

[markthefixer]

You can try re-capping the sx-850's tuner, which involves replacing the electrolytic capacitors on the tuner card.

Also, you should check the power supply voltage when the tuner is distorting, it could be dropping due to a failing capacitor on the power supply board.

There's a lot to try before going to the trouble of shipping it.

The electrolytic caps loose value or short out after 20-30 years, they are water based chemistry and dry out. It is the second most prevalent general failure mode, the first is corroded contacts in the switches, which deoxiting fixes nicely.

 

[Ottovan]

Ok well what I I just replace the whole board with a (known good) board? Should there still need to be alignment to my specific sx-850?

 

[ARC Tech-109]

So why replaced the entire board? It's going to be just as much work to remove the board, the connection pegs and dial cord as it would to just remove the two bad PA-1001 & 1002's add a couple of IC sockets and then remove the two good ones from the donor board. Been there done that with my 1080 and it's still working just fine but I'd first start replacing those small signal electrolytics before getting too crazy regardless of which board you decide to go with. You don't need anything crazy esoteric or magical here just common electrolytics of the same voltage ratings and capacity. As markthefixer suggests also replace the smaller power supply capacitors as they can pull the supply voltages down however I wouldn't replace the big caps that supply the power amplifier unless they're leaking or confirmed bad, I've been repairing Pioneer receivers for over 40 years and have only replaced a small handful of those.

I'm not exactly on Long Island but always willing to work something out for the AK members.