[ROLAND] [SPD-SX] – [WILL NOT POWER ON]
New to the forum!
Does anyone have a service manual for this sampling pad?
I can only find one on line for the SPD-S which has a conventional mechanical power switch on the rear of the unit (not a soft switch on the front panel) and the boards are slightly different.
Thanks in advance 
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• Model & revision/OS: SPD-SX
• Symptoms (what changed, when):
• Tests already done (voltages, parts replaced): REPLACED ALL SOFT SWITCHES, CHECK INCOMING VOLTAGES ON AC ADAPTER WHICH REACH 1ST INDUCTOR ON BOARD
• Photos / audio clips:
Hi, welcome.
It’s on https://www.manuals.altervista.org but might cost you.
Thanks a mill, sargfowler.
At least there’s a chance of getting hold of one, even if I have to pay.
Roland Instruments UK are unhelpful and won’t release the service manual, except to authorised service agents, despite a rep telling me on the phone that that would be no problem as it’s a legacy product 
The Contact Us page link on Altavista doesn’t take you anywhere and there’s comments on a forum about this dating back to 2010 > 2015
What is it that you are looking for in the service manual?
The power supply and soft switch power on circuitry detail.
Try this first.
SPD-SX Power button intermittent or non-functional
Problem: Power button intermittent or non-functional
Cause: As drummers play, the drumsticks shed tiny particles of wood. And almost all drummers using the SPD-SX position their unit next to the hi-hat, where stick shed is most prevalent. Consequently, the shed falls down through the 3 knob holes close to the power button. As this wood accumulates (and due to the vibration of playing) it eventually migrates and builds up under the rubber switch, keeping the button from conducting as the power button is pressed to the contact.
Fix: The Front Panel PCB is removed and the wood particles cleaned off thoroughly. This method works 100% of the time. Very few units have ever needed to be fixed again for the same problem, but those that do return are usually from drummers that gig all the time.
I’ve had the switch assemblies completely to pieces, cleaned the PCB contacts and replaced all the buttons on the unit with a new set from Roland, so it’s not dirt or wood particles under the buttons.
Do you know the voltages on the rails for the power supply?
If so, you could get a multi output PSU to replace it or use separate regulators for each rail.
I think I got you the wrong one last time. This is the power switch schematic.
That’s perfect, just the ticket!
Thank you very much for your assistance.
Geoff
I was wondering if you figured out the power issue. I just had one in with the same problem and it seems to me to be that the main board broke down. Please let me know what your thoughts on the cause is. Thanks!
If an unregulated or wrong adapter is used to power up the unit it will result in regulator failure and the applied voltage will be passed through to all the chips that are powered by the 3 volt supply. All those chips will subsequently be destroyed. The only recourse in such a case is replacement of the entire main board assembly. Some units also use a polarity protection diode that will permanently short out when a power adapter is used with a polarity that is the reverse of the Roland specified power adapter. This permanent short will then result in the destruction of any power adapter that is connected to the unit, whether proper or not, until the protection diode is replaced.
