V-Synth randomly won't turn on straight away

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JDBoy
Posts: 45
Joined: 08:02, 8 April 2016

V-Synth randomly won't turn on straight away

Post by JDBoy »

Anyone ever experience this? it seems the longer it's left alone the longer it takes to turn on.

Original V2 V-Synth. Have tried reuploading V2 firmware, factory reset, new patches etc... nothing has fixed it thus far so not a software error.

For example if I turn it on and off (when it's been on OK) it works fine. If I leave it for a few hours when I turn it on there is a delay (no lights, no screen light) 10 seconds or more then it fires up, it doesn't appear to be a boot up problem more like a power problem. If left overnight it can take a long time to come on or many on/off switch cycles to get it to come on.

Any techies know if this sounds like a failing PSU (caps, regulators etc)? Any idea what to check. I know my way around synths having fixed quite a few in my time (lots of old analog) and have been inside a V-Synth before to fit all new tact switches (not this V-Synth this is a 'new' unit to me).

Also the LFO dpth 1 knob doesn't work (dead) but turning the formant 1 knob turns both that and the lfo parameter/knob icon on screen, is this simply a dead pot that when replaced would get operation as normal, maybe a logic IC fitted on the control board nearby (LN chips usually) or does it sound more serious? anyone heard of this on a V-Synth? I'm thinking it just needs a new pot, and that being dead it's confusing the scanning of the panel.

Thanks for any advice.
JDBoy
Posts: 45
Joined: 08:02, 8 April 2016

Re: V-Synth randomly won't turn on straight away

Post by JDBoy »

Ok, further testing shows that when the screen comes on finally - say after 8 seconds, the loading of the samples (project) is around half way through, so clearly it IS getting power at switch and booting up. So it appears it's a screen issue, the screen is taking a long time to power on/light up even though the synth is powered up ok. And if it's just switched off then on it's fine (immediate screen light up) but when left for some hours the screen takes longer.

So I guess the new question is, is that a sign of a failing screen or LCD invertor? surely someone has had a failed screen and knows the symptoms when one is on the way out? (I also assume they are hard to find and expensive to replace)

thanks

edit for future readers I found a thread about this very issue: viewtopic.php?f=17&t=13928 but no answers!
oldgearguy
Posts: 9
Joined: 11:16, 30 March 2016

Re: V-Synth randomly won't turn on straight away

Post by oldgearguy »

JDBoy wrote:Anyone ever experience this? it seems the longer it's left alone the longer it takes to turn on.

Original V2 V-Synth. Have tried reuploading V2 firmware, factory reset, new patches etc... nothing has fixed it thus far so not a software error.

For example if I turn it on and off (when it's been on OK) it works fine. If I leave it for a few hours when I turn it on there is a delay (no lights, no screen light) 10 seconds or more then it fires up, it doesn't appear to be a boot up problem more like a power problem. If left overnight it can take a long time to come on or many on/off switch cycles to get it to come on.

Any techies know if this sounds like a failing PSU (caps, regulators etc)? Any idea what to check. I know my way around synths having fixed quite a few in my time (lots of old analog) and have been inside a V-Synth before to fit all new tact switches (not this V-Synth this is a 'new' unit to me).

Also the LFO dpth 1 knob doesn't work (dead) but turning the formant 1 knob turns both that and the lfo parameter/knob icon on screen, is this simply a dead pot that when replaced would get operation as normal, maybe a logic IC fitted on the control board nearby (LN chips usually) or does it sound more serious? anyone heard of this on a V-Synth? I'm thinking it just needs a new pot, and that being dead it's confusing the scanning of the panel.

Thanks for any advice.
One suggestion (already mentioned this over on GS...) - go into diagnostics (hold Oct +, -, and #8 key on power up) and jump to the A/D tests. If you see any of the controls moving on the screen without you touching them, there's an issue on that circuit board. One possible problem is that something was dropped on the panel (or the synth took a beating during shipping) and the circuit board has a crack in it. When the power or ground to the pots is flaky, the OS thinks someone is moving the pot. In my case, the C1/C2/arp rate knobs were misbehaving and because the synth was constantly dealing with what it thought was a lot of pot turning, other things didn't function exactly correct (after touch was dead for example).

Similar pots are available from Mouser, but the shaft is too long and will need to be cut down (if the pot is actually bad).
JDBoy
Posts: 45
Joined: 08:02, 8 April 2016

Re: V-Synth randomly won't turn on straight away

Post by JDBoy »

oldgearguy wrote:
JDBoy wrote:Anyone ever experience this? it seems the longer it's left alone the longer it takes to turn on.

Original V2 V-Synth. Have tried reuploading V2 firmware, factory reset, new patches etc... nothing has fixed it thus far so not a software error.

For example if I turn it on and off (when it's been on OK) it works fine. If I leave it for a few hours when I turn it on there is a delay (no lights, no screen light) 10 seconds or more then it fires up, it doesn't appear to be a boot up problem more like a power problem. If left overnight it can take a long time to come on or many on/off switch cycles to get it to come on.

Any techies know if this sounds like a failing PSU (caps, regulators etc)? Any idea what to check. I know my way around synths having fixed quite a few in my time (lots of old analog) and have been inside a V-Synth before to fit all new tact switches (not this V-Synth this is a 'new' unit to me).

Also the LFO dpth 1 knob doesn't work (dead) but turning the formant 1 knob turns both that and the lfo parameter/knob icon on screen, is this simply a dead pot that when replaced would get operation as normal, maybe a logic IC fitted on the control board nearby (LN chips usually) or does it sound more serious? anyone heard of this on a V-Synth? I'm thinking it just needs a new pot, and that being dead it's confusing the scanning of the panel.

Thanks for any advice.
One suggestion (already mentioned this over on GS...) - go into diagnostics (hold Oct +, -, and #8 key on power up) and jump to the A/D tests. If you see any of the controls moving on the screen without you touching them, there's an issue on that circuit board. One possible problem is that something was dropped on the panel (or the synth took a beating during shipping) and the circuit board has a crack in it. When the power or ground to the pots is flaky, the OS thinks someone is moving the pot. In my case, the C1/C2/arp rate knobs were misbehaving and because the synth was constantly dealing with what it thought was a lot of pot turning, other things didn't function exactly correct (after touch was dead for example).

Similar pots are available from Mouser, but the shaft is too long and will need to be cut down (if the pot is actually bad).
Not had chance to reply over on GS yet, but thanks for your advice it was spot on!
Based on that and my gut instinct (and general good condition of the synth) I figured it would be a small break if anything so went ahead and opened it up, it was all good inside, zero damage, even checking the trace by eye it looked ok, but with the multimeter I confirmed it has super high resistance and no continuity. I used a small bit of wire to jump the points and it all worked 100%

And already tested them in the hidden service menu hence knowing that some other pots were affecting it slightly, after the fix, they are all working 100% no erroneous fluctuations or weird stuff.

As a side note, the screen problem is possibly just a common roland flaw based on Temperature, so until a time it becomes impossible I'll live with it. I mean it turns on fine MOST times and definitely seems worse if I've moved it to a colder room.

Anyway, thanks again, without that tip-off I may have put off looking (thinking I'd need to source a pot or chip) so, cheers!
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