Pioneer Tuner still pissing me off...

[Stefan Toftevall]

Hi all,
This is my 2nd post bout this F****ING tuner which is giving me gray
hair....
It used to operate for weeks, then could suddenly be completely silent
for hours and resume again..
Lately, it has been more quiet than sounding, so it has been a little
easier to have signals and voltages measured during fail-state.
It's a Pioneer model F-Z460L.
I've noticed some hokus pokus going on around the detector IC LA1265.
Please, take a look on the following link:
http://www.elektronikcentrum.com/LA1265.pdf
Take a look at page 3 of this pdf doc.
IF is present on pin1 all of the time, so frontend is ok.
DC-levels on pin 1,2,3 is corrupt when tuner fails. (p1=0.5v, p2=1.8v,
p3=0.5v)
All 3 pins should have the same dc-levels normally, around 2v.
Also, during failing, detector oscillation stops (pin 5 and 6).
And pin 13, which is signal meter output, reads completely zero volts.
Of course I've replaced the LA1265 and the detector coil, with no
improvment.
I've no idea what can make the '1265 act like this.
The customer is tired of the time it takes for me to solve the
problem.
He calls me next to every day.......
Please, take a look on the link above, you might be the one who can
tell me
what's going on here...

ANY ADVICE IS WARMLY APPRECIATED!

Regards
Stefan

 

[Bill Bolle]

Hi all,
This is my 2nd post bout this F****ING tuner which is giving me gray
hair....
It used to operate for weeks, then could suddenly be completely silent
for hours and resume again..
Lately, it has been more quiet than sounding, so it has been a little
easier to have signals and voltages measured during fail-state.
It's a Pioneer model F-Z460L.
I've noticed some hokus pokus going on around the detector IC LA1265.
Please, take a look on the following link:
http://www.elektronikcentrum.com/LA1265.pdf
Take a look at page 3 of this pdf doc.
IF is present on pin1 all of the time, so frontend is ok.
DC-levels on pin 1,2,3 is corrupt when tuner fails. (p1=0.5v, p2=1.8v,
p3=0.5v)
All 3 pins should have the same dc-levels normally, around 2v.
Also, during failing, detector oscillation stops (pin 5 and 6).
And pin 13, which is signal meter output, reads completely zero volts.
Of course I've replaced the LA1265 and the detector coil, with no
improvment.
I've no idea what can make the '1265 act like this.
The customer is tired of the time it takes for me to solve the
problem.
He calls me next to every day.......
Please, take a look on the link above, you might be the one who can
tell me
what's going on here...

ANY ADVICE IS WARMLY APPRECIATED!

Regards
Stefan

It looks to me that all the anomalies trace back to pin 1. I would
suspect that there is a solder splash, cracked trace or a component
that is heat sensitive that is causing the DC shift at pin 1. Try
isolating pin 1 during a failure period and see if the other pin
levels return to normal.
Bill

 

[jtech]

It looks to me that all the anomalies trace back to pin 1. I would
suspect that there is a solder splash, cracked trace or a component
that is heat sensitive that is causing the DC shift at pin 1. Try
isolating pin 1 during a failure period and see if the other pin
levels return to normal.
Bill

Is this muting on both am and fm? If not and just fm, maybe look upstream
to the tuner and maybe and if buffer transistor having problems ??

 

[jtech]

Is this muting on both am and fm? If not and just fm, maybe look upstream
to the tuner and maybe and if buffer transistor having problems ??

That was I.F. buffer not if.

 

[Rod2414738]

Hi all,

This is my 2nd post bout this F****ING tuner which is giving me gray
hair....
It used to operate for weeks, then could suddenly be completely silent
for hours and resume again..

I recently repaired a faulty tuner in a Yamaha RX-V660 receiver. It too would
work for awhile, then fail, and eventually work again. Finally it stopped
working all together.

I removed the tuner card from the receiver and noticed a fair amount of
questionable solder joints, so I decided to resolder them. In the process,
while reflowing joints on a couple of electrolytics, I noticed that fishy
smell. This occurred on two capacitors, both 1uF, 50V radial caps. I checked
the tuner for more of the same, these were the only two 1uf, 50V caps and also
the only ones that were bad. I believe they were Rubicon (maroon casing). I
checked them for capacitance and they were right on, but they were infinite in
ESR. I put in new ones and the tuner worked great.

Good luck!
-Rod

 

[Stefan Toftevall]

I recently repaired a faulty tuner in a Yamaha RX-V660 receiver. It too would
work for awhile, then fail, and eventually work again. Finally it stopped
working all together.

I removed the tuner card from the receiver and noticed a fair amount of
questionable solder joints, so I decided to resolder them. In the process,
while reflowing joints on a couple of electrolytics, I noticed that fishy
smell. This occurred on two capacitors, both 1uF, 50V radial caps. I checked
the tuner for more of the same, these were the only two 1uf, 50V caps and also
the only ones that were bad. I believe they were Rubicon (maroon casing). I
checked them for capacitance and they were right on, but they were infinite in
ESR. I put in new ones and the tuner worked great.

Good luck!
-Rod

Hi all,

Well, believe it or not but I think I've solved the problem with the
tuner from hell. The latest week it has not been operating a single
time.
I noticed corrupt dc offsets on the IF amplifier stages, pin 1,2 and 3
in the LA1265. Whenever the tuner was working these pins had the same
dc offset of around 2.0v. After isolating 75% of the pins of the ic
from the circuit board, I suddenly got the correct dc's on pins 1-3.
Hmm..
After some careful inspection I realized something made conduction
between pins 14 and 15, can't really tell what, but I think some old
flux from the soldering or similair had started to conduct. I cleaned
very carefully and scratched away everything between the ic's legs,
finally spraying on some protective transparent, isolating spray, and
tuner started directly.

Thanks everyone for your advice!! You're the best!

Regards
Stefan

 

[Ken G.]

Buy a new stereo there only about 100 bucks

 

[mo]

[email protected] (Rod2414738) wrote in message news:<[email protected]>...

Hi all,

Well, believe it or not but I think I've solved the problem with the
tuner from hell. The latest week it has not been operating a single
time.
I noticed corrupt dc offsets on the IF amplifier stages, pin 1,2 and 3
in the LA1265. Whenever the tuner was working these pins had the same
dc offset of around 2.0v. After isolating 75% of the pins of the ic
from the circuit board, I suddenly got the correct dc's on pins 1-3.
Hmm..
After some careful inspection I realized something made conduction
between pins 14 and 15, can't really tell what, but I think some old
flux from the soldering or similair had started to conduct. I cleaned
very carefully and scratched away everything between the ic's legs,
finally spraying on some protective transparent, isolating spray, and
tuner started directly.

Thanks everyone for your advice!! You're the best!

Regards
Stefan

Good on ya buddy
I did not help,but I know how it feels you finally
crack a frustrating one.

- Mo -

 

[tlw]

Pioneer issued service bulletin for this problem back in 1990. Ceramic
filter going bad. Part # ATF-208. Can't tell you schematic # since I don't
have a s/m for this particular model, but you'd be able to tell which one
from the new one. Old one is in white plastic case. New one covered with
grey shrink wrap.

 

[Stefan Toftevall]

Pioneer issued service bulletin for this problem back in 1990. Ceramic
filter going bad. Part # ATF-208. Can't tell you schematic # since I don't
have a s/m for this particular model, but you'd be able to tell which one
from the new one. Old one is in white plastic case. New one covered with
grey shrink wrap.

My problem had nothing to do with the ceramic filters.
They were totally isolated from the circuit while the tuner was failing.

--- Stefan

 

[tlw]

Sorry, thought you were a technician.