Pioneer 980 receiver vintage

Robert Belt

Hi Group,
I am new and this is my first question I was wondering if some one could help me.

I have a Vintage Pioneer AM/FM Stereo Receiver, every thing is working but the FM has no out-put.
The tuner knob when moved shows I have a signal (on the meter) and the tuner meter needle centers when
I start to shows I getting a station. The two watt meters do not move or show and movement.
The Stereo light does come on when I find a station but no sound.

Help please....Ha! Ha!

Robert

TNHNDYMAN

How strong is the signal strength if you have meters on the rcvr? Do you have any type of antenna connected to the rcvr, if not a piece of speaker wire maybe 5' spread at one end to form a T would work. Do you have a FM mute button on the receiver and if it's pushed in, you won't get any sound unless it's a strong signal...

The FM mute keeps static from going thru the speakers as you slide the dial between channels, but it also blocks iffy reception.

More info, and we will try to help.

Robert Belt

Hi,
Thank you for the fast reply.
I have had this receiver since it was new. I am familiar with it working the FM just stopped working one day.
The signal strength is all the way up to its normal range I get all the time, around 3-4 (I am in a basement).
The antenna is the same one for the last 37 years Ha! Ha!. The mute button I have tried, no change.

I did remove the cover and checked all the fuses, looked for loose wires, charred or blacken items
(Cap., resistors, broken items etc.)
I am thinking its and FM chip of some kind.

Does any of that help?

PolkieMan

Hey does the AM work?
Could it just be the FM button on the front is bad from you pushing on it all these years?

Robert Belt

Yes, the AM does work. It could be, when I push in the FM button I hear nothing.
I looked at the push button and from what I can see they are metal covered. If I remove a few PC boards
I can take a better look. That is a great idea.
How would I check that out? I am not as knowledgeable you you guys (I have been an electrician 35 years) and
only know just enough to be dangerous. I have replaced some PC item over the years before but they have been
obviously bad (blacked, smoking etc....LOL).

Thanks I feel like I am making some progress.

[Deleted User]

Hello,
I found the schematic for the Pioneer and it looks like the output of the tuner section goes through a "function/equalizer assembly" that has several switches and selectors. It's possible that some of those selectors aren't making contact. If you can find these selector switches and clean them with a good contact cleaner that might be a good place to begin. Having the "stereo indicator" illuminated is a good sign, that should indicate that the tuner section is working.
Regards, Ken

Robert Belt

Hi Ken,
Thank you for chiming in on my problem.
"function/equalizer assembly"..........Ha! Ha! you techies sure have some long phrases.

Where would that be located or is it part of the "sliding switch assembly" for the FM button?

Thanks, Robert

[Deleted User]

Ah, I understand. That's actually what was on the schematic, so I thought there might be a front panel selector with that description. I can't tell from the photos I find on the web, but there looks to be some selectors near the middle of the front plate. In all likelihood the receiver has a removable bottom plate that might give you access to the inside of the switches. I recommend using Deoxit contact cleaner and cleaning all of the switches. A selector switch is a lever that moves a contact plate between two or three contacts, making and breaking connections as the lever is moved. Over time those contacts get oxidized and no longer make contact. Hopefully that's what's happened in your case.

Robert Belt

Okay, I just turned on the unit one more time before I start pulling it apart and I see the stereo light
does not come on (earlier post I said it did, sorry that may change things) the FM light is on and all the
meters (signal/ tuner) move as I get close to a station....but no sound. AM still is great.

I pulled the items apart all the way down to the FM push button on/ off slider switch. I then opened the
slider switch and looked in side, all looked well. Pulled out all eight (8) copper slide contacts, they were clean,
tight, with no sign if pitting. The vertical metal post they slide over also looked great. I cleaned them with tuner
cleaner re-assembled all the little parts, put everything back together and turned it on and the receiver still has no FM.......
but it was fun....LOL

So......here I sit listening to AM again.
Any other ideas or are any of you close to Gaithersburg, Maryland.
I think I need some one with more knowledge.

PolkieMan

I'm sorry that wasn't it, but it was worth a try.

I'm in Texas:cheesygrin:

You know I had a sx1050 and it would mute the sound tuning in between stations so you would not hear the
grrrrrrrrrr..r.rr.r.rrrrr sometimes it would stay muted even though I was tuned to a station so I would play around
with the buttons on front till it would start working again, that was 1986.

Robert Belt

Hmmmmmmm Texas, I should have guessed because everything is bigger in Texas even the receivers.........LOL

I have played with all the buttons, switches and knobs to no avail.
What I need at this point is someone that can follow the circuit and find the part/parts that keep the FM from working.
I know at one point the stereo light did com on when I hit an FM station and now no light. So the problem could be
anything.
If it was wiring in your home I could fix it but this is just a little past my knowledge.

Thank you anyway for the help, if you see a BIG box at your front door please see if you can find the problem...Ha! Ha!

Happy New years tooooooo all...............(That is a BIG "too" because of Texas)

George Grand

Robert Belt wrote: »

I think I need some one with more knowledge.

We lent you Swaugierre. It doesn't get much better than that.

Robert Belt

Group,

Thank you for lending me Swaugierre, not sure what/who that is.........but thank you.
What I should have said is........
"I think I need some one with more knowledge then I have"

Any one on this forum is more knowledgeable then I will ever be.

If any one would like to try to repair my receiver please let me know and I can sent it out.

Robert

George Grand

None of this (except the engineering stuff) is rocket science. Honest. It just takes getting pissed off/ballsy enough to pop the cover and let your eyes do the walking. Unplug it from the wall first unless you're REALLY ballsy. Look straight down on it with the cover off, activate/rotate some of the controls, and you can probably see the actions INSIDE the machine, and the contacts/parts that require cleaning.

Robert Belt

So, you this it is a contact problem and not an electrical problem.

I have the receiver open setting next to me and I have played with every thing I can play with.

Okay I am going in.........contact me later I may have a unit for sale that can be used for parts...LOL

[Deleted User]

Hello Robert,
Send me a PM with your email address and I can send you a copy of the service manual and a few tips on what to begin looking for. However if the problem is with the tuner section itself and involves Pioneer's proprietary ICs the repair is far from easy.
Regards, Ken

Robert Belt

Hi Ken,
Thank you any help is appreciated, my email address...

riverotterct@gmail.com

PolkieMan

Yea Kenneth Swauger helping you is as about as good as it gets.:cheesygrin:
And no, in Texas all we have is old beat up pickup trucks with AM radios and tumble weeds:cool:

George Grand wrote: »

We lent you Swaugierre. It doesn't get much better than that.

George Grand

Robert Belt wrote: »

So, you this it is a contact problem and not an electrical problem.

I think it COULD be a contact problem. What we're recommending is a very inexpensive way of either eliminating the problem, or giving you the satisfaction of knowing that if you do take it to a shop, they can't tell you it had $2-$300 worth of expensive technical repairs, when all THEY did was clean the contacts.

ErasmusBDragon

the 80 series of Pioneers were prone to have problems. You may need to take it to a skilled audio tech.

Robert Belt

Thank you to you all, I have tried everything I know how to repair and after a week on my bench covers off meters probing
all I know I can not find the problem. So I think it is time for a skilled audio tech person to take a crack at it.

Thanks again for all your input, I will fill you in after they look at it. This my take several weeks.

Robert

Oldmanind

Any older receiver I have ever owned the first thing I did was clean all the contacts and controls. Mint condition or not.

Robert Belt

I did clean all the contacts and even opened and looked at the slides and post points of contact.

I am sure with all the other items working AM, Phono 1 & 2, and Aux....even when on FM I get the signal meter (4-5) and
the tuner meter centering plus the stereo light goes on and off as I turn the tuner knob past stations.
I just can not get any FM music out..................very frustrating.