To owners who owns Marantz Receivers from 80's 90's with Digital Tuner

[bikingbuddha]

I have a Marantz Receiver model name - SR-73. Exact same model as depicted in the picture. It is a pro-Logic. My question is

"Does your receiver remember the stations after you memorise them with preset numbers? ( after you remove the A/C plug from the wall outlet and put it back on after about ten minutes)"

because mine does not, it forgets it after a little while. I have to keep it on standby to remember the presets. I just wanna know if this is normal or something is wrong?.

I don't have much experience with these stuff because this is my first real receiver.

 

[bikingbuddha]

I also found this information

http://www.nrpavs.co.nz/archive_2_12/Sold_2_12_htm/MarantzSR-73.htm

It says

Marantz SR-73 av Dolby Pro Logic av receiver - black :
Late 90s high quality Dolby Pro av receiver with no remote control

Specifications :
-:®:- Vintage : 1997 model
-:®:- Power rating : Front: 70W x 2 [at 8ohms], Centre: 80W [8ohms], Surround: 20W x 2 [8ohms], 40W x 2 [4 ohms]
-:®:- Total Harmonic distortion : Front: 20Hz to 20khz 8ohms at 0.09% THD
-:®:- Inputs : 7 audio, 3 video inputs
-:®:- Outputs : 3 audio, 2 video outputs
-:®:- Pre-outs : Front, Centre and Surround pre-outs
-:®:- Dolby Pro Logic processing only
-:®:- Speakers : Front speakers [A, B, A+B], surround x 2, centre
-:®:- Sound fields : 5 preset acoustic memory for storing desired surround fields
-:®:- Channel levels : Built in surround sound test tone generator
-:®:- Tuner presets : 30 station random preset memory with auto preset memory <--- Does this means it loses memory once power is disconnected?
-:®:- Remote : capable - no remote with this unit
-:®:- Volume control : can be remote driven
-:®:- Colour : black
-:®:- Dimensions [ W x H x D ] : 420 x 132 x 334mm
-:®:- Weight : 9.4kg, packed ~ 11kg

 

[Tom B]

Modern digital receivers such as this use either a ni-cad battery, or a super capacitor to keep the memory alive of preset stations. The battery will usually be a battery similar to a AA battery rated at 1.2v. But I think this unit may use a "super Capacitor" The cap is usually rated at 5.5v and has a value of 0.047 farad to 1.5 farad.

Search on ebay to see what they look like or try searching on this below in ebay
Universal 5.5 V 1.0F Super Capacitor C-Type Button 5mm Capacitance 1.0F US Ship

Both the super Capacitor and battery will need to be unsoldered and the replacement soldered back in.

 

[bikingbuddha]

Modern digital receivers such as this use either a ni-cad battery, or a super capacitor to keep the memory alive of preset stations. The battery will usually be a battery similar to a AA battery rated at 1.2v. But I think this unit may use a "super Capacitor" The cap is usually rated at 5.5v and has a value of 0.047 farad to 1.5 farad.

Search on ebay to see what they look like or try searching on this below in ebay
Universal 5.5 V 1.0F Super Capacitor C-Type Button 5mm Capacitance 1.0F US Ship

Both the super Capacitor and battery will need to be unsoldered and the replacement soldered back in.

Thank you so much. You just saved my ol' amp , I will do a search and post the results.

 

[bikingbuddha]

https://www.electronica-pt.com/esquema/old-tv/marantz-vintage/marantz-sr-73-service-manual-31258/

I found this too.

 

[bikingbuddha]

Modern digital receivers such as this use either a ni-cad battery, or a super capacitor to keep the memory alive of preset stations. The battery will usually be a battery similar to a AA battery rated at 1.2v. But I think this unit may use a "super Capacitor" The cap is usually rated at 5.5v and has a value of 0.047 farad to 1.5 farad.

Search on ebay to see what they look like or try searching on this below in ebay
Universal 5.5 V 1.0F Super Capacitor C-Type Button 5mm Capacitance 1.0F US Ship

Both the super Capacitor and battery will need to be unsoldered and the replacement soldered back in.

Alright, here goes what i did. I took off the top cover of the amplifier and looked for super-caps and batteries. I couldn't find any. Then after about half and hour of searching all over the observable universe (Circuit area) i saw something very similar to those super-caps you mentioned. it's on the front panel in a place where it is super hard to remove because i am not a qualified technician and finding one here is crazy. I thought i'd take a picture of it and post it so you can have a better look at it. The green flat little thing looks so much like a super-capacitor. What if i solder one on the back of the circuit without removing the existing ones? will it overload with power and die? i know it us a super stupid question, but i'd do anything to avoid removing and taking things apart.

 

[wmgwizard]

"--- Does this means it loses memory once power is disconnected?"

No

It means the unit will scan the dial and begin populating the presents with the strongest stations it comes across.

Unfortunately you will have to bite the bullet and disassemble the unit. I believe the blue/green item in the photo is in fact a battery that is used for memory retention. While some older units used AA/AAA size batteries, a significant number use a "button" type of battery similar to one used in a key fob for you car, just thicker due to the higher voltage and with solder tabs.

 

[Tom B]

That green component looks like a super capacitor to me. But I do suggest removing the old, find out if it is a capacitor or button battery, and then replace it. When you remove it, be aware of its positioning. If its a capacitor it will have a value, as well as voltge rating (5.5v usually), and one of there will be a -, or black stripe where the negative connection is. If it is a battery, it will usually be rated at 1.2v, and one of the leads will usually be marked with a +.