Roland RD 700 abrupt loss of sound output, also unable to access SRX cards as evidenced by not confirming access on display

Synth Repair
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I lost sound output on this piano abruptly. I did a factory reset after removing my srx cards, without success. The midi in, out, thru are all working fine. The display comes on appropriately, pressing the function buttons cycles through the different menus appropriately, so I am at a loss on how to proceed.

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Is there any sound on any of the other outputs?

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No, nothing. I tried the headphone output, no luck; and demo mode as well no luck. I have rack modules routed in to this keyboard also and the midi out function is working so I can produce sound since I have all of my keyboards and rack modules routed through a mixer so I can easily check them. I realize that I have to tear into it, I justdont know what to look for. The small instrument boards are a challenge for me.

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It’s worth opening up the case to check everything looks OK inside.

Get the service manual (if haven’t already) from https://www.synthxl.com/roland-rd-700/

and go through the various test modes.

5

Thank you for the advice on downloading the service manual. I didn’t know that Roland had one for this piano. I went through the test modes that I could, and this what I found:

Device Check

DSP1: NG DSP2:

EXP A: EXP: B

WROM1: WROM2:

ERROR: IRAM

I was unable to do #8 the sound check, the oscilloscope test because I don’t own one yet. There was no sound being generated at all. Nothing from the headphone jack. Everything else checked ok. So…Base on this info. I believe that the RAM module-IC 5 and the tone generators IC 24 and 25 are my problem sources. I haven’t yet opened it up since I need to obtain an oscilloscope to complete the test modes. To surmise, I probably need a main board. What do you think?

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If you’re not familiar with board repairs, then yes, buy a new board.

There may be one on Syntaur?

RAM chips and ROM chips always go on older stuff. I’ve replaced a few and have fixed several synths. At least you know what the problem is now.

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Thanks for pointing me in the right direction. I found one (used) on eBay for an RD 700GX. I didn’t see a part number for it and I’ve yet to open mine up. Syntaur doesn’t list one on their website.