Just bought my first Rhodes, looking for a little help diagnosing it

[400hands]

Hello! This is my first post here on this forum - I've dreamed of owning a Rhodes for years and recently had the opportunity to scoop one up! This is a 1979 (stamped 4179) Mark II Suitcase 73 model, with wooden keys and a Rhodes FR7710 cabinet. I paid a great price because it's been sitting in the basement of the music store I work at, and only went up for sale recently, although it was in a kind of indeterminable condition.  - I know in the future I'll order the Vintage Vibe refurb kits for things like the tonebar grommets, action, etc, but for now my biggest concern is making sure it can make noise! I'll also include pictures - if anybody would like any specific shots or angles, let me know and I'll be happy to grab some for you.

I know Mark IIs have a high pickup failure rate , and I'm really hoping I don't have 40+ dead pickups like I've seen on some examples while looking over the forums. I have a decent set of tools, a good soldering iron, and a general understanding of the workings of the keyboard (I am a training guitar technician and have been working on my own instruments for about as long as I've been playing them, but this is my first instrument of this caliber that needs a big amount of love) and am confident in doing the work on my own, but I could certainly use some help / pointers / resources. Below I'll post some issues I'm having.

 - Sometimes, when powered on for too long or even shortly after powering on, the power switch light will start flickering and crackling. I always unplug it when it does this.
 - I get no sound at all, unless I touch a screwdriver to a certain solder point on the first or second pickup while also making contact with the tonebar (completing the ground?). This allows me to get a very scratchy sound from the first 5 or so keys from the cab, but if I plug the accessory out into an amp I get about 8 keys total in varying volume all over the keybed, going up to say about the 55th key.
 - My tremolo / vibrato unit doesn't seem to work... maybe that's just the sound quality of the signal not being very clean but if anybody has advice on things to check please let me know.

I know I'm sorta asking for a lot here, but I know I'm a little in over my head while still trying to remain confident that I'll get it singing again. I'm a 19 year old multi-instrumentalist and I think I could walk away from this keyboard with a lot of good tech experience under my belt. Thank you all!

[gacki]

Congrats! I own a similar 88 model.

If I was in your position I'd start from the tone generation and then work my way up through the electronics. So to check all the pickups I'd suggest using it without the internal amp for now. Connect the RCA jack from the harp to a guitar amp and you're good to go. Gently tap the magnets for each pickup with a metal screwdriver and you'll hear a loud "thud" for working pickups. This should get you started.

I believe the power amp in this model suffers from cold solder joints on the molex connectors; so this is something to look out for. I certainly had to reflow a number of solder joints in mine.

It seems to me as if there is some corrosion throughout the piano. Make sure that everything makes good contact (this of course starts again with the RCA jack).

[sean]

Very good.  With 400 hands, you can get lots of alligator clips working.

Please read this:  https://ep-forum.com/smf/index.php?topic=4641.msg22547#msg22547 
(Oh Goodness, that post is sixteen years old!)

Specifically for pickup stuff, see this:  https://ep-forum.com/smf/index.php?topic=7116.msg36655#msg36655
I think it says pretty much the same thing as:  https://ep-forum.com/smf/index.php?topic=3839.msg17262#msg17262

You should also read the service manual a few dozen times, this link works:  https://www.fenderrhodes.com/service/manual.html
Vintage Vibe has a pretty clean pdf version at https://cdn.shopify.com/s/files/1/0666/2821/files/Rhodes_Manual.pdf?6596484715058753348
----- -----

Your tremolo unit is the Janus preamp.  Very simple circuit, but there are three versions of that preamp: (I have the five knob version.)

Yours should match one of these schematics:
Schematic for Janus preamp with sliders: https://www.fenderrhodes.com/org/manual/fig11-1.jpg
Schematic for Janus preamp with sliders, version 2: http://www.fenderrhodes.com/pdf/late-mark1-suitcase-janus1.pdf
Schematic for Janus preamp with five knobs: http://www.fenderrhodes.com/pdf/late-mark2-suitcase.pdf

See also https://www.fenderrhodes.com/service/amp-diffs.html

For testing, you can power the Janus preamp with a pair of 9V batteries.  Or you can use your suitcase cabinet with the five-pin cable, and all that.  Or you can build your own: 
https://ep-forum.com/smf/index.php?topic=9706.msg53682#msg53682
https://ep-forum.com/smf/index.php?topic=9657.0

Don't build your own.

Sean

[400hands]

Very good.  With 400 hands, you can get lots of alligator clips working.

Please read this:  https://ep-forum.com/smf/index.php?topic=4641.msg22547#msg22547 
(Oh Goodness, that post is sixteen years old!)

Specifically for pickup stuff, see this:  https://ep-forum.com/smf/index.php?topic=7116.msg36655#msg36655
I think it says pretty much the same thing as:  https://ep-forum.com/smf/index.php?topic=3839.msg17262#msg17262

You should also read the service manual a few dozen times, this link works:  https://www.fenderrhodes.com/service/manual.html
Vintage Vibe has a pretty clean pdf version at https://cdn.shopify.com/s/files/1/0666/2821/files/Rhodes_Manual.pdf?6596484715058753348
----- -----

Your tremolo unit is the Janus preamp.  Very simple circuit, but there are three versions of that preamp: (I have the five knob version.)

Yours should match one of these schematics:
Schematic for Janus preamp with sliders: https://www.fenderrhodes.com/org/manual/fig11-1.jpg
Schematic for Janus preamp with sliders, version 2: http://www.fenderrhodes.com/pdf/late-mark1-suitcase-janus1.pdf
Schematic for Janus preamp with five knobs: http://www.fenderrhodes.com/pdf/late-mark2-suitcase.pdf

See also https://www.fenderrhodes.com/service/amp-diffs.html

For testing, you can power the Janus preamp with a pair of 9V batteries.  Or you can use your suitcase cabinet with the five-pin cable, and all that.  Or you can build your own: 
https://ep-forum.com/smf/index.php?topic=9706.msg53682#msg53682
https://ep-forum.com/smf/index.php?topic=9657.0

Don't build your own.

Sean

1.) That 16 year old post - - !! I was 3 years old!

2.) Thank you so much for the response! I've been reading through the service manual since before I even took the thing home, but most of these links are unfamiliar to me - I've been making more and more progress with diagnosis and this community has been so helpful with furthering it. Thank you!

[400hands]

Congrats! I own a similar 88 model.

If I was in your position I'd start from the tone generation and then work my way up through the electronics. So to check all the pickups I'd suggest using it without the internal amp for now. Connect the RCA jack from the harp to a guitar amp and you're good to go. Gently tap the magnets for each pickup with a metal screwdriver and you'll hear a loud "thud" for working pickups. This should get you started.

I believe the power amp in this model suffers from cold solder joints on the molex connectors; so this is something to look out for. I certainly had to reflow a number of solder joints in mine.

It seems to me as if there is some corrosion throughout the piano. Make sure that everything makes good contact (this of course starts again with the RCA jack).

Thank you for the reply and pointers! I've been trying to go through and use DeOxit 100 on whatever connection points I can, but I haven't seen any connections I think I'll have to re-solder (unless somebody sees anything in the images - let me know!) but I am trying to clean that corrosion off. This specific keyboard has lived in the basement of a music store for ten years (along with various other instruments, including guitars, brass, and stock for rental instruments. I don't think it's been in a very aggressive environment, but does that corrosion indicate that I'm wrong? It certainly hasn't been exposed to elements but I know the effect that kind of environment can have. I've been down there during all seasons of the year and it never seemed to humid or especially dry...