XP-50 after hiss

Forum for JD, JV, XP and XV synthesizers from 1990's
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DrRog
Posts: 5
Joined: 22:02, 25 February 2012

XP-50 after hiss

Post by DrRog »

Hi, Roger here from New Zealand. New Member.

I have an XP-50 I've had from new and lately its becoming almost unusable due to a nasty hiss which occurs after I have released a note, then slowly dies off, with a little chirp at the end. This happens on every patch, so is not patch related.

In reading through this forum, I cannot find a solution although I have noticed that there is advice to replace C931 & C932 after 5 years? This makes sense as capacitor leakage could cause the problem.

Will this fix the problem?

All help greatly appreciated.

Thanks you,
Roger
DrRog
Posts: 5
Joined: 22:02, 25 February 2012

Re: XP-50 after hiss

Post by DrRog »

Well I decided to shotgun all the 24 electros on the main board. It worked!

If anyone else has this problem, you might get lucky & know exactly which caps were the problem, but my shotgunning method removed all the potential problems. Result!!
GreyFortress
Posts: 2
Joined: 16:16, 30 May 2012

Re: XP-50 after hiss

Post by GreyFortress »

I just did this as well and I think you may be correct that 921 & 922 are the culprits. I replaced a few caps, tested, replaced a few more, etc. It wasnt until I did 921 & 922 and two others that the hissing problem was resolved.
DrRog
Posts: 5
Joined: 22:02, 25 February 2012

Re: XP-50 after hiss

Post by DrRog »

Great result!
JCoenraads
Posts: 1
Joined: 01:44, 24 December 2012

Re: XP-50 after hiss

Post by JCoenraads »

Hi: John Coenraads here. New member in Victoria Canada.

I too experienced after hiss like Roger described. Replaced C922 and C921 as suggested but problem persisted. Not wishing to replace all the caps, I checked the circuit diagram, and because the problem was left channel only, I identified all the relevant caps, C11, C8, C175 and C93. I then replaced and tested, and when I got to C175, the problem disappeared. (C174 is the corresponding right channel cap)

Thanks to the Forum for putting me onto the fact that the caps were the problem, and I hope that my discovery will help someone else.

BTW, the local parts supplier had a 2000 minimum for SMD caps so I used regular caps from my parts supply bending the leads into little "feet" which I tack soldered onto the board. Worked like a charm.

Cheers John
Wavemaker
Posts: 4
Joined: 14:00, 12 December 2010

Re: XP-50 after hiss

Post by Wavemaker »

I have a XP-60 with low hissing noise from left outpout in all patches and performs, i think it's same problem as XP-50. I don't use it that much now but i have it brand new since Oct 1999 and i can barely listen the hiss with my AKG-140 MKII but i'm afraid it will get worse.

Is the circuit diagram similar to the XP-50? I'm afraid i'll have to send it down to Roland service i can't replace the capacitors on my own. Do you recon they are the same caps as XP-50?
DrRog
Posts: 5
Joined: 22:02, 25 February 2012

Re: XP-50 after hiss

Post by DrRog »

As far as I can tell, the XP60 shares the XP50 main board problem, wavemaker.
noelc
Posts: 1
Joined: 10:18, 16 February 2013

Re: XP-50 after hiss

Post by noelc »

DrRog wrote:Well I decided to shotgun all the 24 electros on the main board. It worked!

If anyone else has this problem, you might get lucky & know exactly which caps were the problem, but my shotgunning method removed all the potential problems. Result!!
Greetings from Ireland.

My trusty old XP-50 has recently developed the same problem, i.e. a hiss that lingers after the note release has died away, and which ends in a chirping sound. The display contrast has also gone in the last week or so. I'm loathe to ditch this keyboard and was thinking of replacing all the electro caps as you have done. Did you use SMD caps?

Its a while since I've worked on repairing anything electronic. What do you guys recommend? A regular temp controlled soldering station or something like the Aoyue 852A hot air SMD rework station?
DrRog
Posts: 5
Joined: 22:02, 25 February 2012

Re: XP-50 after hiss

Post by DrRog »

Yes, just smd caps. I used my trusty old Weller solder station.
roland_xp
Posts: 4
Joined: 21:12, 29 November 2014

Re: XP-50 after hiss

Post by roland_xp »

Hello ! I have a big problem with my keyboard . At the begining, when it startup , after few seconds blocks himself...i mean the software doesn`t respond . I`ve replaced all capacitors on the mainboard with the same values of original caps , all capacitors from power source and now the xp 50 doesn`t stop anymore ...it work perfectly but appears a hiss when i press the flaps ...remember ! the caps are new and SMD . I`ve measured voltages from power source and there are 5,03 volts .... +15,3 volts and -15,4 volts. I`ve made FACTORY TEST and no change. i`ve entered in TEST MODE and results:
CPU....ok
DRAM..ok
SRAM..ok
Battery..3,1 v
all butons respond to comand
bender ..ok
BUT at SOUND test appears L sine and the sound in left speaker is very distorted follows the message Rsquare ...distorted sound in right speaker and after that R/W checking....R/W ..ok i :31 D:36 press enter and out from test mode . What`s mean R/W ok and i:31 D:36 ???what can i do to repair ? please i need help
su222
Posts: 1
Joined: 19:04, 29 December 2015

XP 60 disturbing noise

Post by su222 »

I'm about to pull the trigger on a XP 60 with 4 boards installed , it's in Decent shape for it's age , the problem is it plays the internal patches with no problems , but when a patch from the expansion boards is selected , the sound is produced but with an annoying noise or buzz , it does this randomly, not on every patch from the EXp. Board, , I don't really need the boards so having the internal sounds only , is not really an issue for me , but it's nice to have the Exp. Board handy when needed of course , what do you guys think ? Have any of you had a similar issue ? Do you guys think it'll be OK as long as you don't bother with the Exp. Board and just use the internal Factory patches ? Please help, as I'm about to bring this baby home soon !!!! THank you guys ... And Happy New Year to all !!!
Subtox
Posts: 4
Joined: 17:55, 8 March 2016

Re: XP-50 after hiss

Post by Subtox »

I just turned on my XP-50 for the first time in years and I'm having the hissing issue described here. Given the reply from JCoenraads I think I'll start with C174 and C175. The thing is, I know how to solder components but I'm no electronics expert so I am not sure how to identify the exact capacitors I need. The schematic shows "16CV10" below these two capacitors, if that explains it. I would appreciate any help you guys can give me in translating this to the values I need to make an informed purchase. Thank you!
cmcglone14
Posts: 1
Joined: 17:52, 20 August 2016

Re: XP-50 after hiss

Post by cmcglone14 »

Hello, all!

Conor from New York here, new member.

Subtox, I am in the precise situation you were in this March. I hear a hiss from all outputs (L,R, and headphones), and I gather this requires a capacitor replacement. I am alright with a soldering iron, but I am baffled by circuitry--but did you have any luck with (A) pinpointing the exact capacitors to change or (B) figuring out the best model/make of capacitors to buy for the replacement??

Thanks in advance!

Best,

Conor
Subtox
Posts: 4
Joined: 17:55, 8 March 2016

Re: XP-50 after hiss

Post by Subtox »

Hey Conor. I don't know if you're even still dealing with this, but just to address your post... I finally got around to revisiting this project last week. I replaced all of the mainboard's electrolytic capacitors but there was no improvement. In fact there is absolutely no sound now, whereas before there was at least a hiss and a tiny amount of sound coming out. I'm pretty sure I did something wrong and it's not a question of faulty capacitors or a blown IC.

There is a good thread with lots of info on the capacitors themselves and some knowledgeable people discussing both LCD and sound issues at viewtopic.php?f=50&t=33500. The conversation is still pretty recent (last post was last month) and I just posted my latest misadventures a couple days ago and am waiting on any replies.
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