D-50 issues Power Up

Synth Repair
1

My brother passed me a D-50 some time ago. I never powered it up, but he had mentioned key issues and a battery issue to me at the time.

A little stupid, but didnt power up the unit before starting all this.
Opened the unit and replaced 3 keys (got the keys from you guys) and the CR battery. Used your procedure for the new keys. Took extreme care with everything.

Powered it up and nothing, on power up got the
“*** Expanded Linear Synthesizer D-50 ***
Roland Corporation Musitronics” on the screen.
(I assume that is has the expansion card in the unit.)

Then, powered it off, and then on again, and now I have nothing on screen, only the red light next to VALUE. Tried INCREMENT and Zero and nothing.

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If I leave the unit off for about about an hour, and power it up again, I get the same thing, the message on screen. Then power down and up, again nothing, just a blank screen.

Now it seems it just goes to the blank screen.

given the message came up I assume the screen is working.
Recognising the battery was changed, that would mean all the data is lost,
would that also mean the diagnostics are gone as well?

Would really appreciate some assistance from anyone that can help.

I am not an electronics person, but I am a tech, so I will do my best.

Extra Info. Just talked to my Brother. He said only way he could use the unit before was with a Card. Noted that he “thinks” he powered the unit up with the card in and was then able to use the unit. He is going to try and find the card.
I have a small midiman unit that I can use the upload the data to the unit if I need to do this… but I am concerned about not having diagnositcs options.

2

I’ve never owned one so this is a stab in the dark. Sometimes (I’m looking at you Wavestation) these klunky old operating systems gets confuzzled when asked to load a patch whose waveforms aren’t all accessible in memory. This can happen if there is a patch in internal memory that references a waveform on a card, and the card isn’t inserted. In the case of Wavestation, it locks up, and requires disassembly and pulling the battery then initializing the patch memory on the first boot. I suggest this just because of your edit.

If this doesn’t help, my next suggestion would be opening her up and looking for leaking swollen caps, and carefully removing and replacing all cables and socketed chips. Be very careful with old ribbon cables. They break easily if kinked or if not inserted gently and squarely into their socket. Regarding caps, the D50 is 40 years old. Every synth I own from this period had failing PSU caps. Some were leaking badly.

3

The unit now has a blank screen.
As noted, the battery was pulled out and replaced.
Ok, so if initializing the patch memory might be required, how do I do this, if there is no diagnostics or display?
Is there supposed to be something on screen when you do this?
I think I will look for someone to service it here is Aus if I can.

4

sounds like a brownout on power on. a detailed check the power supply and all voltages is required. Time expired electrolytic capacitors would be the main culprit, and failed tantalum Caps second somewhere on the motherboard second.

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