Mazda 626, Fujitsu tuner

[Wayne Tiffany]

I have a Fujitsu Ten modular radio (Model AE-3050TY1A, S/N 9102692) in my
1985 Mazda 626 and the tuner has developed a problem. It would occasionally
lose its presets, as in clearing its memory. My first thought was that the
constant +12 supply line was dropping, but I caught the tuner blanked out
one time when I had the meter hooked up, and the supply was still there. So
then I thought maybe it was a cracked solder joint, but a trip of all the
boards under the microscope found none.

I have checked the ESR of all the major caps and all appear to be ok. I may
have missed something there as I just received & built my ESR meter over the
weekend. But I compared caps of similar sizes, and also compared to others
I had, and I didn't find any that raised alarm.

The original symptoms started about a year ago, but were so random that I
could never catch it being bad long enough to do any more than wiggle wires,
etc. Now it finally totally quit, so whatever was deteriorating, finally
quit.

Has anyone been through one of these? Any guesses out there? Schematics
available? Thanks for any help.

WT

 

[Franc Zabkar]

I have a Fujitsu Ten modular radio (Model AE-3050TY1A, S/N 9102692) in my
1985 Mazda 626 and the tuner has developed a problem. It would occasionally
lose its presets, as in clearing its memory.

Has anyone been through one of these? Any guesses out there? Schematics
available? Thanks for any help.

In the past I have managed to obtain parts and schematics for
Toyota/Fujitsu Ten gear from Fujitsu Ten (Australia).

In North America you could try the following:

Fujitsu Ten Corp. of America

Address:
19600 South Vermont Avenue
Torrance, CA 90502
U.S.A.

Contact:
Tel: +1-310-327-2151
Fax: +1-310-767-4355

Business activities:
Manufacture, sales and service of car audio products and car
electronic devices.


- Franc Zabkar

 

[Wayne Tiffany]

Thanks - I'll call today.

WT

 

[JR NORTH]

Vibration damage to car stereo boards is common. Look for
components/boards that are mounted at right angles to the main board and
soldered to it. Vibration usually will damage the solder connections
here over time. Resolder the input plug connectors, 90° boards and tall
components, like caps and tuner section, where vibration is magnified.
JR

 

[Wayne Tiffany]

Thanks for the thoughts - I'll check it out this weekend. Any more out
there?

WT

 

[Wayne Tiffany]

A bit of further observation. I have had the radio installed since the time
of this post and after paying attention to it, I find that it works ok if
the temperature is below about 75° F, and also above about 40° F. I've seen
devices become sensitive to being too hot, but never one that would also
quit at a low temperature. Any more thoughts?

Just another note - I have gone over the boards under a microscope and found
no solder problems.

WT

 

[Asimov]

"Wayne Tiffany" bravely wrote to "All" (29 Nov 04 08:11:24)
--- on the heady topic of "Re: Mazda 626, Fujitsu tuner"


Definitely bad solder joints...


WT> From: "Wayne Tiffany" <[email protected]>

WT> A bit of further observation. I have had the radio installed since
WT> the time of this post and after paying attention to it, I find that it
WT> works ok if the temperature is below about 750 F, and also above about
WT> 400 F. I've seen devices become sensitive to being too hot, but never
WT> one that would also quit at a low temperature. Any more thoughts?

WT> Just another note - I have gone over the boards under a microscope and
WT> found no solder problems.

WT> WT

 

[Wayne Tiffany]

Here's another interesting update. I haven't had the time recently to pull
it back out, so I am in the observation mode.

This morning it was about 25°F and of course, the radio would not work
properly. However, I did listen to local TV channel 5 for a while! It
lasted until the interior of the car warmed up a bit, then back to static,
then to some radio station that I never did identify. All this without any
response from the buttons or display. So, since channel 5 frequency is
below the bottom end of the FM band, it would appear that I have something
that is drifting to the low side. Interesting.

WT

 

[Don]

You might want to check the voltage along the trace instead of a visual
inspection. I had a similar problem with the stereo in my '82 Supra (I
think it was a Fujitsu). I ended up running a jumper from the connector
where the +12VDC standby came on the board to an IC on the far side of the
board. Followed the trace to get there, but there did not appear to broken
anywhere.

Good luck!!

Don

 

[Wayne Tiffany]

Were you having these kinds of temperature issues? You're also suggesting
that there is a micro sized crack not visible that's causing the issue?
Hmmm, could be - I'll try that next time I pull it out. Thanks.

WT

 

[Don]

Wayne,

If I recall correctly, the problem was actually occurring in the summer.
The radio would loose all it's presets during the day when the car sat out
in the sun. I would reset everything on my way home from work and I seem to
remember it holding most of the time until the next day. Obviously, it was
cooler in the evening and the car was garaged once I got home. Certainly
sounds like you are having thermal problems.

Good luck with it!

Don