Marantz ST46K Tuner Display problem. My ST46K tuner works OK except that the display is so dim as to be essentially "off". It has a vacuum florescent display. For many months it was intermittent, either full on or off. Now it is always very very dim. The power to the display board is apparently OK (I measured 5.6 volts). I wiggled all connectors, there's no obviously burned part (no blown caps, etc). Any ideas how to fix this?

The 'click' may be a relay failing to operate correctly

Hello Tvin, I have read what you have put, depending on that look for the service manual and I told you that it is very possible that the amplifier stage works well, you can check it, if you have a CD player or another sound source, if you listen, definitely the amplifier stage, it works
Regarding what you observe that when you look for the stations, your Marantz tunes them, which does not indicate that the sound comes out, I tell you why, there are several stages within the radio,
The stage of tuning and location of the stations, is the one that indicates that it found the station and it indicates it in the display, next there is the stage decoder stereo and audio output, this stage is the one that is in conflict
If you have technical knowledge, I will send you the link of the service manual, but look for a specialized technical service
I hope you can listen soon, the radio stations in your Marantz
Greetings Franco Dosil

Hola Tvin, he le?do lo que has puesto, en funci?n de eso busque el manual de servicio y te comento que es muy posible que la etapa amplificadora funcione bien, puedes comprobarlo, si tienes un reproductor de CD u otra Fuente de sonido, si lo escuchas, definitivamente la etapa del amplificador, funciona
Respecto a lo que observas que cuando buscas las estaciones, tu Marantz las sintoniza, lo que no indica que el sonido salga, te cuento el porque, existen varias etapas dentro de la radio,
La etapa de sintonia y ubicaci?n de las estaciones, es la que indica que encontr? la estaci?n y lo indica en el display, a continuaci?n esta la etapa decodificadora est?reo y salida de audio, esta etapa es la que esta en conflicto
Si tienes conocimientos t?cnicos, te env?o el link del manual de servicio, sino busca un servicio t?cnico especializado
Espero puedas escuchar pronto, las estaciones de radio en tu Marantz
Saludos Franco Dosil
https://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.php?pdf=Marantz-SR-60-L-Service-Manual.pdf

You may have many different issues in the FM circuitry. Do any other FM stations come in?

If you are interested in having your Marantz repaired, please visit my website at audioserviceclinic.com. You may contact me there. Thank you.

It's VERY possible that the Tuner has a "backlit" display ( Like many of the 1980-90's Yamahas)...You'll need to replace a couple of small bulbs inside

It's VERY possible that the Tuner has a "backlit" display ( Like many of the 1980-90's Yamahas)...You'll need to replace a couple of small bulbs inside.

Hello

If auto search is going on smoothly, and there is no stations on air is memorized, and display no signal, there are tow possibilities. The first one is antenna is not connected properly. Check the antenna connection for firm. The second one is tuner fault. If the tuner inside the tV is faulty, or it does not gets proper voltage to work, this type of fault land display will see on screen. Check if proper voltages are comming to the tuner section in circuit board. If voltages are ok, and still there is no signal display, just check it with external video input. That is, connect it to any dvd or cd with AV connector, and set the TV to AV mode and play a disc. If there is picture, the video side of your TV is OK. If not, Video-chroma-RF jungle IC is faulty, and not the tuner. OK.

Hello,
Make sure your FM antena connection is good. A receiver will not pick up an FM signal without an antena. Even a small piece of wire will work to test. If the Tuner section is bad, an external tuner can always be connected to an Aux input. Due to cost, it may not be cost effective to repair this unit.
Hope this helps.

Ive found with the AS655 Ive been working on,the lights will come on after about2-5 mins of use.this isnt a fix,just a comment.

SONY MHC-EX50

Het is al een paar weken verder, maar ik ben eruit: C161 en C162 (100uF/35V) in de voeding zijn slecht.
------------------------------------------------------------------------------------
wel 105 graden elco's gebruiken en hoger dan 35 volt, liefst 100v
------------------------------------------------------------------------------------
et gaat dus om een VFD (Vacuum Fluorescent Display) die geen gloeispanning krijgt. Het vervangen van C161 en C162 lost het probleem helemaal op.
------------------------------------------------------------------------------------
Radio: ST-EX100
Amp: TA-EX50
------------------------------------------------------------------------------------
Symptome=Tuner-Display zeigt nichts an, sonst Tuner OK.
Defekt=C161 und C162 (100µF,35 V) auf der Tunerplatine ersetzen.
------------------------------------------------------------------------------------
Wenn bei dem Sony-Tuner RDS EON ST-EX100 (z.B. zu der Anlage Sony MHC-EX5, aber auch MHC-EX 70) pünktlich eine Woche nach Ende der Garantiezeit die Beleuchtung im Display wegfällt und man deshalb leider keine Sender mehr programmieren kann, dann handelt es sich vermutlich um eine fiese Soll-Bruchstelle.

Auf der Platine des Tuners sind zwei Kondensatoren zu schwach ausgelegt und gehen zwangsweise früher oder später kaputt. Die Reparatur ist ganz einfach. Man kauft zwei neue Kondensatoren (100µF,35 V) - kosten nur ein paar Cent! - und besorgt sich einen Lötkolben. Dann schraubt man den Tuner auf, entfernt auf der Platine die Kondensatoren C161 und C162 (die sind namentlich gekennzeichnet) und ersetzt sie durch die neuen.

The display will dim for certain features that are not available for use in your current configuration or current operation.
For example; if you do not have an antenna plugged in then the selection for the tuner will be dimmed on the display.