Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« on: September 12, 2017, 03:51:12 PM »
Hey everyone!

I recently picked up an Ibanez SDR-1000+ (which is functionally and circuit-wise identical to the Sony MU-R201) which I was enjoying very much. If any of you know this unit, you know it's a fantastic reverb that's got an excellent early digital reverb vibe, which works wonders on synths and electric guitars.

I plugged it in and it was working just fine, (save for some dust and some loose pots that I tightened), until all of a sudden the VFD display just stopped working. It was still passing signal, (both dry and wet), and functionally it was working just fine. I just couldnt see anything on the VFD display.

I contacted a few repair shops that gave me quotes that are worth more than me just fixing it myself, and I'd like to give it a shot! I already took apart the unit and separated the front panel where the buttons and display are, and I'd like to know how to troubleshoot this guy and fix her up!

Thanks everyone, and I look forward to tackling this issue with you guys!  ;D ;D

Btw, I have attached the schematics and user manuals here. The repair manual is for the MU-R201, but it's got everything the same on the inside.

https://drive.google.com/file/d/0B9ibEgfmCUqdNDdJM1B2OHBnWDQ/view?usp=sharing
https://drive.google.com/open?id=0B9ibEgfmCUqdNGMxaUtkZURxWGM


PRR

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #1 on: September 12, 2017, 06:54:30 PM »
I don't suppose there would be any Voltages to check? (Say, page 48?)

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #2 on: September 12, 2017, 07:01:33 PM »
I don't suppose there would be any Voltages to check? (Say, page 48?)

Hey PRR, thanks for responding. Are those numbers circled in red voltages? (My schematic reading is pretty sub-par :P)


mrclunk

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #3 on: September 12, 2017, 07:17:18 PM »
No they aren't the voltages.
I repaired one of these a couple of weeks ago.
The voltages are printed on the pcb silk screen in various places. +12v +5 and +/- 15V i think.
Check the 4 fuses by the power transformer.
The one i repaired was for US mains voltage and didn't have a mains fuse so be careful!

PRR

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #4 on: September 12, 2017, 07:32:49 PM »
.

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #5 on: September 12, 2017, 07:52:05 PM »
No they aren't the voltages.
I repaired one of these a couple of weeks ago.
The voltages are printed on the pcb silk screen in various places. +12v +5 and +/- 15V i think.
Check the 4 fuses by the power transformer.
The one i repaired was for US mains voltage and didn't have a mains fuse so be careful!

Hey thanks! Here is a picture of the fuses below; call me crazy but I think that the last one needs replacing!

What should I set my multimeter to, and what should I be reading off of of the fuses?

Thanks!


PRR

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #6 on: September 12, 2017, 10:59:37 PM »
How does a fuse work?

It is a very small resistance when "good", a nearly infinite resistance when "blown".

Very-small may be 1 Ohm. Infinite is like when the ohm meter probes only touch air.

The bigger question is: why did it blow? Right after you blew it out and tightened pots?

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #7 on: September 13, 2017, 07:55:18 PM »
How does a fuse work?

It is a very small resistance when "good", a nearly infinite resistance when "blown".

Very-small may be 1 Ohm. Infinite is like when the ohm meter probes only touch air.

The bigger question is: why did it blow? Right after you blew it out and tightened pots?

I remember seeing it glowing after I touched the display board (with the VFD on it) to the chassis. Maybe a short of some kind?

squarewave

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #8 on: September 13, 2017, 10:44:37 PM »
Do you have any 20mm fuses (higher current or otherwise)?

Those look like standard 20mm fuses. Get 20mm 0.8A fuses from your local electronics supply like mouser or farnell depending on where you are. I would say chances are good the fuses are the problem.

If you just want to sanity check to see if there's some other problem (that caused the fuses to blow) you could move the two good ones to where the bad ones are (they're all the same 0.8A) and use the bad ones to wedge a piece of buss wire where the good ones were. Meaning bypass the fuses. The rational is that if the good ones didn't blow, the circuits it supplies are probably ok and you might get away with jumping the fuses temporarily. Then power on and see what happens. If the same fuses blow again you have bigger problems. If they work and everything is functional then it's probably just fuses in which case you can order some.

But I wouldn't use it for longer than 2 minutes with the fuses bypassed. It could torch something more critical like some chip that would be really hard to identify or replace.

Personally I wouldn't even try bypassing the fuses at all if you really care about the unit. But I have lot's of 20mm fuses. A 1A fuse would probably be fine. Maybe some other old piece of gear has some you could commandeer?

radardoug

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #9 on: September 14, 2017, 01:34:39 AM »
Do you have any 20mm fuses (higher current or otherwise)?

Those look like standard 20mm fuses. Get 20mm 0.8A fuses from your local electronics supply like mouser or farnell depending on where you are. I would say chances are good the fuses are the problem.

If you just want to sanity check to see if there's some other problem (that caused the fuses to blow) you could move the two good ones to where the bad ones are (they're all the same 0.8A) and use the bad ones to wedge a piece of buss wire where the good ones were. Meaning bypass the fuses. The rational is that if the good ones didn't blow, the circuits it supplies are probably ok and you might get away with jumping the fuses temporarily. Then power on and see what happens. If the same fuses blow again you have bigger problems. If they work and everything is functional then it's probably just fuses in which case you can order some.

But I wouldn't use it for longer than 2 minutes with the fuses bypassed. It could torch something more critical like some chip that would be really hard to identify or replace.

Personally I wouldn't even try bypassing the fuses at all if you really care about the unit. But I have lot's of 20mm fuses. A 1A fuse would probably be fine. Maybe some other old piece of gear has some you could commandeer?
Thats bad advice! Just buy a bunch of the right fuses, its not like they are expensive. If you have a multimeter, check across the filter cap for shorts.


squarewave

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #10 on: September 14, 2017, 04:15:26 PM »
Thats bad advice! Just buy a bunch of the right fuses, its not like they are expensive.
As I said I wouldn't bypass the fuses. But in this particular scenario, because all of the fuses are the same, you could remove the good fuses and put them where the bad fuses are and see if they blow again. I suppose it really boils down to how important this particular piece of gear is to you. If it's beat up and you got it for $50 on Ebay maybe it's worth the risk before ordering fuses on some website.

Actually, one thing that they could do is just use the 2 good fuses where the 2 blew (and not have any fuses where they didn't). So there will be no bypassing and thus no danger. The unit will not completely power up of course but if you see the display come on then that's a strong indication that new fuses will fix the problem.

radardoug

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #11 on: September 14, 2017, 04:38:38 PM »
As I said I wouldn't bypass the fuses. But in this particular scenario, because all of the fuses are the same, you could remove the good fuses and put them where the bad fuses are and see if they blow again. I suppose it really boils down to how important this particular piece of gear is to you. If it's beat up and you got it for $50 on Ebay maybe it's worth the risk before ordering fuses on some website.

Actually, one thing that they could do is just use the 2 good fuses where the 2 blew (and not have any fuses where they didn't). So there will be no bypassing and thus no danger. The unit will not completely power up of course but if you see the display come on then that's a strong indication that new fuses will fix the problem.
No thats not a good idea. How much are fuses? 50 c each? You want all of the device going. If the microprocessor is on the supply you pull the fuses on, then the display will never light up.

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #12 on: September 17, 2017, 06:20:53 PM »
No thats not a good idea. How much are fuses? 50 c each? You want all of the device going. If the microprocessor is on the supply you pull the fuses on, then the display will never light up.

I just ordered a pack of 20mm 800mA fuses, and I'll report back with my findings!

nuts

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #13 on: November 20, 2017, 08:53:08 AM »
 Hi, so what did you finded jcdenton825 ?

Mine also have the VFD that goes wrong after some time, and the audio cuts at the same time, i may start another thread.

mrclunk

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #14 on: November 20, 2017, 10:39:13 AM »
Check the continuity of the ground bus bars [the copper strips] to each circuit section on the pcb.
Any cracked solder joints?

nuts

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #15 on: June 13, 2018, 05:56:21 AM »
Check the continuity of the ground bus bars [the copper strips] to each circuit section on the pcb.
Any cracked solder joints?

Thanks mrclunk, didn't came here for  a long time, sorry. I have time for bench stuff again and  I will do that.
Although I had already heated  them (PSU) again,  I examined the PCB and could not determine dry solder joints. Will do a second check asap, and may I reflew them all, after all ? I hope its not a burned IC or something.

Capacitors look good but may be one is dying slowly hence the audio and VFD going south when the unit is hot ?
Should I recap the whole unit maybe ? It is a quite expensive job, and i could not afford until now honestly. Better if i start with PSU recap only maybe.. don't know what to to.

I want my unit back on track so bad.  :)

mrclunk

Re: Ibanez SDR-1000+ (Sony MU-R201) VFD display?
« Reply #16 on: June 13, 2018, 09:26:14 AM »
It is a quite expensive job, and i could not afford until now honestly. Better if i start with PSU recap only maybe..

Don't bother recapping the whole thing until you've worked out what's wrong.
But if the psu is dodgy, and u don't have an esr meter, replace the physically small caps that are close to a heat source to start. They'll dry up first.

BUT, check the bus bar joint's first!
I fixed another one recently, same fault...