Yamaha SPX90 II Repair and Teardown - Part 1

A very sad classic Yamaha SPX90 II needs some attention. In this first part we tackle and repair the power supply which is a common failure on these effect processors.

[@joeschmo4695]

Thank you so much for this video Brad. I was given a semi-functional SPX90 (v1) by a friend who got it from a gear shop. Apparently the previous owner thought it was a bad input jack and decided to spray WD-40 into the unit (possibly while it was on [protip: never do this]) Your video helped me diagnose and figure out why the 5V was working and the 18V wasn't. All it took was 8$ in new caps from Digikey, a thorough cleaning and it's now got a second life again.

[@Yupppi]

People still seem to love using this unit for snare. I was hunting one of these for a good while and one seller even backed off after a couple of weeks of trying to close the deal saying he'll keep it after all. He started with saying that he has one laying around unused and only used it for snare ever. I was looking for that Symphonic patch for Zakk Wylde and other 80's stuff on guitar, and for that the "inferior" technical specs actually helped (like top end roll off). I'm so happy that mine doesn't show any signs of giving up at power supply yet. I heard the display panels are also common to fail. But at least after seeing this, it's likely an easy fix even by myself.

[@anthonypaloccijr.9243]

Putting new caps in my spx90 ii as well- started yesterday. The diode of D7 exploded and corroded - smoke came out of the rack! My big boi cap is also bulging - had to send away for that one from mouser, my local electronics store had all the others and the diode, and graded for hi temps. What I wanted to mention was - I realized after wrestling w the power supply board that the bottom of the rack case is actually detachable as it’s own flat piece of sheet metal - with the sides and back/front of the rack remaining intact. This makes it super easy to access the top and bottom of the board, for deinstalling and installing new parts. I am making my own little video to explain. As an electronic novice I found that accessibility extremely helpful. I’ll link to this one. Very informative. Thanks.

[@matosetbidouilles]

Hello!, well done! 30 minutes ago, I ve fixed an old SPX 90 at work (no start-up , 3V instead of 5V on PSU). Big cleaning for power supply board (insisted with this brown dough...) , many weird weldings to redo. I've changed C23 & R18, very corrupted legs on these ones

[@steffenbrix]

I LOVE YOU! Been wanting this for years....

[@PhilBennett3D]

I recently bought one with a bad PSU (no +5V or +/-18V). I replaced all the electrolytic caps to no avail. I then removed over a dozen components to test out of circuit, all of which were within tolerance. Just as I was about to give up and go to bed, I decided to power it on again and lo and behold, it started working! Must have been a bad solder joint? I did check it over initially but didn't notice any dodgy joints. Well done me anyway :)

[@DemonGamer684]

you're the best man. As a Tech Director now, i used to look at your videos !! Do you repair consoles? Repairing a Mixwizard would be awesome

[@matrix12x]

great video

[@theaudioeng]

Ahhhhhh! This may be the issue with mine just stopped working about 3+ yrs ago now, in garage to be looked at Brad. If this is common issue, I may well be able to fix it easily..... 😎👍🎹🎶🍻

[@evanpontoriero516]

very helpful thx

[@Moneygrip]

I just picked up a spx90 ii and its doing this exactly

[@Makuz1988]

Thank You!

[@velonaut303]

Where do you find the voltage input/output specs for the gear? I assume the service manual, but I was excited to see you crack it open, but didn't really cover how to read. I'm still going through your videos, after discovering your channel. I hope to learn more about electronics repair from you. thanks.

[@KumariFarscape]

Thx Brad, good explanations, I have a spx 90 II that comes on, but it buzzes, found 6.7 volts at the 5 volt terminals, replaced all caps on power board, no change, suggestions

[@steffenbrix]

By the way... I have 5 of these. And I'm going to recap them all. Do you happen to have a parts list of caps? That would make it so much more easy - just to be sure I have the parts ready before disassembling :)

[@swanation45]

I’m getting a non powering on SPX90 today. I’m new to fixing this type of stuff. If I can’t figure it out could I send it to you for repair? Thanks! Great vid!

[@GrandpaShreds]

Hi Brad, first of all, thank you for sharing you knowledge and inspiring others like me. I'm looking for a power supply transformer (TYA010) for my SPX90, but I can't seem to find one. Do you know of any alternative transformers that will work?

[@1inDnile]

Hi bradthx,2great informative repair videos on spx 90II I bought mine from new, it failed just yesterday it is my favourite unit in my studio,I intend to fix it could you tell me the best source for caps etc. and do you have a list of the parts and their numbers which you replaced in your video Thank you.

[@livealoha50f]

Great video! Mine has input (I can see the meter) - but no effects output - any advice would be great. Effects are intermittent. They just shut off - I get a little bypass signal but no effects. Also - I would like to maybe to a rebuild anyway- and links to these "caps" - or if someone could please post a list so that a (no-bee) like me could order what I need. Aloha!

[@espacoipiranga]

I have one with a bad transformer TMA007 (pins 3 and 4 are shorted, no inductance)

[@jvalenzh]

Nice video! I have the same model for my bass and it sporadically makes some loud crackling noise while playing notes on the bass and then goes away. I can go several hours without any problems and then it'll do it a few times. Do you have any idea what this could be? Thanks.

[@TunguskaGuitars]

I took a crack at re-capping my original 90 - as with lots of the comments all the caps were basically shot. Weird thing tho - when I measure the voltage on the 5v rail, I get -negative- 4.75v. Any idea what could cause that? I've done some digging and can't find an answer to such a thing. I also checked my multimeter on a 9v battery just to make sure nothing was wonky there, and it's working fine.

[@warnimobv7890]

amazing video! I would like to convert an US model to an European model. The PCB's are the same only some different resistor values and some small amount of other components are different. Do you know if the transformer is the same? If you don't know that, can you tell me the AC voltages on the primary windings of the transformer (pin 1-2 , 2-3 , 3-4) from an European model? What is the difference in the optoisolator? Thanks in advance.

[@danec1384]

Hey Brad, I followed your advice and recapped the power section of my spx90. It turns on and works now but it seems as if all of the effects are distorting and sending a distorted signal to my amp. Guitar/cables/amp are working perfectly (clean amp settings too). Any idea what could cause this? The rest of the caps look OK to me but I will double check the analog side of the digital board. Thanks

[@theopinionmachine606]

Howdy, I have a couple of these I bought brand new as a kid. They were working when they were replaced in my old studio. They have just been in storage but they no longer work. Do you offer a repair service? Thanks for your video.

[@alisabbagh8242]

I have a unit that blew the mains fuse and smoke came out of the smaller if the 2 chokes. Could the filter caps of the mains be done for and need replacing?

[@snoolee7950]

how do you fix the display light on an SPX 900

[@marciofs70]

Hi bradthx, First, thanks for the video I replaced 99% of the electrolytic capacitors from the source I forgot to change the 22uF x 10v C30 When I turn on the spx the lcd display flashes(just half) and the relay makes noise and stops What I realized is that I can't stabilize the 5v output the oscillation is great. ranging from 3.5 to 4.8v, and even if I adjust the trimpot to reach 5v these values ​​keep fluctuating What could it be? Do you think that C30 can be the problem? kind regards Marcio

[@ProudFatherMusic]

Having a lot of trouble locating a few replacement components for my SPX-90. Brad or any commentators, would anyone be down to help with c14, L5,L6,L7 and a few more?

[@jimvalduga]

Hi Brad, I picked up a broken Spx-90. The power supply looks good, +5v look good, +/- 18 looks good. It did have a bad +15 regulator, which I replaced. Now I'm seeing correct voltages on the rails on my chips... The unit still doesn't seem to work. The display is just green squares. The bypass relay (ry102) won't turn on. It attempted to turn on once, the relay clicked three times, and then turned off. Now it won't come on at all when I power cycle the unit. Any ideas what I should look at next?

[@ryanbates362]

I have an SPX90 mark 1 that keeps blowing the 6.8 ohm 5 watt power resistor R2. I've tried to narrow down where the problem is. When I remove the power transformer, the resistor doesn't blow, and removing any component BEFORE the transformer keeps it from blowing so.. could it be a bad power transformer?

[@Bedonius]

Hi, in my SPX 90 II the relay 102 ( I think is the bypass contact) keeps switching. Can you help me please? thanks so much...

[@ManuPro3]

Hi, I have the same model, basically i use it in a Aux send/return but I have some issue. The Yamaha doesn’t output the sound in a proper level, only if I drive the volume in input really high. Can you give me some advice to what look for?

[@benjaminaustnesnarum3900]

I have an SPX-90. Sometimes it works, sometimes it doesn't. It turns on, and it gets stuck flashing between the intro menu saying "YAMAHA v01", and the preset menu (mine is on "Symphonic) - after a while it goes onto the presets, and it works as normal, but it may drop out again; so I suspect it's a faulty connection somewhere (might be the power supply, I don't really know.) - How would I locate the problem, and how could I fix it? I'm new to actual hardware.

[@cuttingedge1987]

Just got one today but needs repairing. The screen is black, and when I turn on the unit, the multimeter goes red...and the sound goes beep beep beep...Do you where I can start looking? Powersupply? analog part? Thank you

[@jpboo24]

Looking at re-capping the power supply on my SPX, but I’m a bit hesitant as I’ve read some warnings about electric shock (especially the big cap on the output of the transformer). Judging by the way you handle the PSU in this video, it doesn’t seem like a big concern. Is this mostly a myth?

[@revhi109]

Any idea why it freezes at the firmware screen?

[@jacoscofield5150]

How do I get rid of hiss noise

[@davidlevene5727]

i own an spx90 everything works but at a very low volume, almost inaudible, i wonder what could it be, it also gives me a low battery warning , could that cause the drop of volume?

[@lede-soudeur3937]

helo i'm eric from france and i have a spx 90 ii withe 110 v and i use a 220 to 110 v tu use it. i can change the internal transfor. ( only the primary ) but what model with what output voltage can i use ? best regards and thanck u eric

[@demodeiowa]

Do you offer repair services for these units?

[@jacoscofield5150]

Where are you located. I wish you could repair the 2 I have

[@poynt99]

Hey Brad, great video. Something I've heard a number of times is that the SPX90II is quieter than the original SPX90. From the specs and service manuals, it seems this should not be the case as both are identical other than the added DRAM for a longer available delay time of 2000ms on the SPX90II. What are your observations on this, do you agree the SPXII is quieter? If it is quieter, can you shed any light on what changes were actually made to accomplish this?

[@bradthx]

Good question, I have both but have not noticed. There are some very minor hardware changes as you noted between them, nothing that should impact noise though. I may have to make a video to see. Thanks for watching!

[@poynt99]

@@bradthx Yes, a video about the hardware differences and audio comparison of the noise would be great, thanks!

[@PedigreeGuitars]

Anyone knows how much voltage should be coming out of the power transformer (T1 on the schematic) ? I believe mine has failed and wanted to get a equivalent unit. Thanks

[@DavidImrie]

Are you still in need of this info?

[@timothycarman3443]

Brad- What ESR rating for the caps is appropriate? Thank you!!

[@bradthx]

I usually don't dwell on ESR when buying new capacitors too much, most manufacturers also don't state the ESR in the datasheets. Any new, name brand high quality cap is going to have a low ESR and likely better overall specs than the original components anyway.

[@richardsmith4992]

Just grabbed a couple of these cheap, but came without any power supply inside - had been swapped out for a 5 pin DIN external supply for live use on stage( not sure what that would need to power up?). Are there any power supplies that would do a good job to drop in to these units, something from Meanwell eg.? Would there be any issues with using a newer power supply on this "old" kit?

[@bradthx]

Technically no, as long as you can provide clean + and - 18VDC and +5VDC it should work. Note the +5VDC line will probably need a couple amps to run all the logic and dsp.

[@richardsmith4992]

Thanks bradthx. Would this PSU work? Was recomended by online forum: www.mouser.com/ProductDetail/Cincon/CFM40T-03?qs=%2Fha2pyFaduhBqtyVrjqWFU5veU4eyBvtv5Yyl8Eg8elbCxhSblZFVQ%3D%3D Details here - www.cincon.com/productdownload/SPEC-CFM40D-T-V14.pdf

[@starwarstitaniumseries6579]

Hi friend great video!!! You can sendme pictures of squematic circuit!!!!!!!!

[@DavidImrie]

Hi brad. Any idea if the screens on these are a generic part that can be cheaply swaped out?

[@bradthx]

Hi David, they can be for sure. Look on eBay for HD44780 LCD displays, 2x16 character. I would measure the one in the SPX90 to make sure it is the right dimensions, but a majority of them are a direct replacement. You need to make sure you buy one with pins on the side as well, not along the top. I discuss this in part II.

[@DavidImrie]

@@bradthx cheers mate. Yes i realised once i watched part 2. I just bought an spx90 but its not arrived yet. Ive ordered this display. Hopefully it will be correct. rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F302180194645 Now i just need to wait on the unit arriving so i can get a component list for recaping.

[@DavidImrie]

@@bradthx Thanks buddy. I've had a really bizarre time with it. Check my channel if you are interested. I'm having limited success finding a working display. I've managed to use the new back light in combo with the old display (after blowing 2 of them before i realised they need a 10ohm resistor in series) for now but I'm determined to figure out how to fabricate a whole replacement for future ref. I figured out that the connector for the display is known as a 14 pin IDC cable.. would you happen to know what the connectors for the display power / the other general motherboard connectors are called? It was really odd but connecting my IDC cable to the old display resulted in it not working and getting real hot as if it were wired wrong... but that's pretty hard to mess up.

[@jafethuerta]

Rookie Question: I recently bought a Yamaha SPX90 and sometimes i hear a "sizzling" sound as soon as I power it On, then i turn it Off, and then On again and no "sizzling" sound. Any help on what that might be ? Thanks !

[@bradthx]

The switching power supply is always the common problem on these units, the noise is most likely from the high frequency transformer. Rebuilding it as I did in this video usually resolves.

[@jafethuerta]

bradthx Thank you very much for the info, I’m gonna get it checked !!

[@sargonrana]

Hi is possible to contact You via phone I have SPX90’s 90 and it stoped working

[@starwarstitaniumseries6579]

Hi friend You can helpme, not have signal yes power on power LED doit allá funtion only not in the efeccts You can helpme !!!!

[@neonether]

This a hugely helpful. I have a new problem with a unit that just arrived from Japan...I'm getting either no sound or crackling from when the effects are engaged. Any ideas or help would be greatly appreciated, as I'm trying to get this up and running for a project. I was stoked because the unit is in mint condition, except for the aforementioned problem. Thanks a million in advance. Here's a video of the issue. kzbin.info/www/bejne/b3-3hYKAgtRljtE

[@Moneygrip]

I just picked up a spx90 ii and its doing this exactly