Sanyo M9994 FM tuners problematic as they age? Can they be fixed?

Matrixambience

Member (SA)
May 8, 2010
259
3
18
57
Strasburg,PA
It's been a year since I have owned two Sanyo M 9994 boomboxes. not the K models. They both had the same basic symptoms of a 40 year old radio. Both cassette players needed full restoration with new belts, lube, etc. I took upon myself during my four month long foot surgery and recovery to do those decks. Quite an experience but very pleased with outcome. They sound great on cassette mode.
Now on with the FM tuner. they are crap!, Did Sanyo just cheese out on the tuners? All my Panasonics, even the little lower line models pick up stations locally much better than both Sanyo that I had "professionally repaired by a shop in Baltimore, MD, 60 miles south of me. I paid $160 each for both tuners to be restored, aligned, cleaned, whatever. they still are not 100%. So much tuner drift, hearing a stupid talk religious station that must be 900,000,000 watts of power! I hear it faintly all the way in quiet passages between more powerful stations in my area. does it make a difference if the shop is miles away, and they do a tuner alignment and use stations in their area to align it? Shouldn't make a difference. Stations and call numbers don't change. Radios adapt to changing localities of broadcast. I just purchased one of those Ion deluxe boomboxes from Best Buy for like 60 bucks, and it picks up stations way better than the Sanyo. I know the Sanyo is 40 years old, but geez come on! Anybody have any ideas? super duper maybe getting a radio to fix for good!
 

Superduper

Member (SA)
Nope, not touching it, lol. But you did get a bad technician. Tuner drift almost confirms instability in the circuits. Sanyo did not use durable transistors in many of their tuners and they do get weak and go bad. To be fair, Sanyo and probably most manufacturers of portable equipment never designed or anticipated the life to be 40+ years. Unfortunately, most of those transistors are obsolete and very difficult to find. I do find however that the tuners on the K models to be more reliable. I’m sure your tuners can be fixed and adjusted but you probably need a guy who specializes in tuner work because those transistors will probably need to be substituted and an experienced tech is better able to find a suitable replacement. Too bad you wasted $160. Are they at least better than when you brought them in?
 

Matrixambience

Member (SA)
May 8, 2010
259
3
18
57
Strasburg,PA
To answer your question, yes, the one improved quite a bit, and I am satisfied with it. Leaving that one alone. Cosmetics wise, it's not as nice as the other one. The nice looking one with no blemishes has the worse of the two pertaining to tuner drift. The audio tech in Maryland had a warrenty of like 60 days, but for some reason, It didn't bother me much when I got it back right away because it is better, but the more I use the radio, it just upsets me more, and warrenty is now gone. I get the whole old radio syndrome design pat it's prime deal but..... like I stated before, my Pannys are 40 years old or close to, and have better reception AFC lock in capabilities. I can live with the tuner drift I suppose for a while. There is a guy in York that I may go to if it bugs me. not the most personable guy to deal with. Guess I will just look past that and hope he can zero tuner in better. I would like to buy a K model sometime down the road. I am getting very good at cassette player restoration on these bad boys! Thanks Super!
 

fyj2972

Member (SA)
Nov 29, 2011
129
38
28
california, usa
I use 51-68P ceramic capacitors. Desolder IF transformer from PCB first ,Destroy the old dull color cap, Resolder IF tranny back, Solder new cap on foil side. then do 10.7 fine tuning alignment.
 
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Josh9994

Member (SA)
Jan 6, 2019
21
12
3
42
AZ, USA
I have a 9994k that suffers from weak FM signal. I can't tell what capacitors need to be changed to improve the reception. Any help would be greatly appreciated.
 

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hopey

Member (SA)
Dec 28, 2014
1,262
278
83
Melb AU
I have a 9994k that suffers from weak FM signal. I can't tell what capacitors need to be changed to improve the reception. Any help would be greatly appreciated.
You might have a hot joint on the aerial. Try to clean it first with fine grade sand paper and grease. This is were the wire screws on to the aerial base.