Vintage Synth Repair

Anyone know if a Roland JV880 display can be repaired? The display 
is good but there is no backlighting. It makes it a little hard to 
make out. If it can't be repaired where can I find a replacement? 
I'm in the usa, Colorado to be exact.

Thanks, Synthflake

I take it you did try to go into the menus and adjust the contrast or do a
hard reset. If you aren't familiar with how to do that, go to Roland's web
site and look at the support section for that unit. If it still doesn't
work, try contacting telesisbacklighting.com They can either repair it or
sell you another one. Hope this helps.

Keith A. Niver
Certified MITA tech
Niver's Service Corp
801 Columbia St
Hudson, NY   12534
518-828-0616, Bus
518-755-6960, Cel
kaniver@...

-----Original Message-----
From: synthflake [mailto:gemjam@...] 
Sent: Saturday, March 19, 2005 11:46 PM
To: vintagesynthrepair@yahoogroups.com
Subject: [vintagesynthrepair] Roland JV880 display




Anyone know if a Roland JV880 display can be repaired? The display 
is good but there is no backlighting. It makes it a little hard to 
make out. If it can't be repaired where can I find a replacement? 
I'm in the usa, Colorado to be exact.

Thanks, Synthflake






 
Yahoo! Groups Links

Ok, a closer look at the display and the backlight is working, just 
not nearly as bright as my Korg 03R/W and Yamaha TG500. Roland told 
me the $115 LCD is now discontinued and telesisbacklighting.com says 
they can't fix those but wanted me to check to make sure I was 
driving enough current for the backlight. Looking inside the unit 
there is a 1/4watt resister (axial) right next to the header where 
the LCD ribbon cable plugs in, I'm wondering if this may be a current 
limiter for the LCD backlight? Seems logical that in a mass of SMT 
devices a single precision 1/4 watter right next to the connector... 
Does anyone have a schematic of the JV880 that might show a LCD 
backlight intensity select resistor?   

Synthflake

--- In vintagesynthrepair@yahoogroups.com, "Keith Niver" 
<kaniver@m...> wrote:
> I take it you did try to go into the menus and adjust the contrast 
or do a
> hard reset. If you aren't familiar with how to do that, go to 
Roland's web
> site and look at the support section for that unit. If it still 
doesn't
> work, try contacting telesisbacklighting.com They can either repair 
it or

> sell you another one. Hope this helps.
> 
> Keith A. Niver
> Certified MITA tech
> Niver's Service Corp
> 801 Columbia St
> Hudson, NY   12534
> 518-828-0616, Bus
> 518-755-6960, Cel
> kaniver@m...
> 
> 
> -----Original Message-----
> From: synthflake [mailto:gemjam@s...] 
> Sent: Saturday, March 19, 2005 11:46 PM
> To: vintagesynthrepair@yahoogroups.com
> Subject: [vintagesynthrepair] Roland JV880 display
> 
> 
> 
> 
> Anyone know if a Roland JV880 display can be repaired? The display 
> is good but there is no backlighting. It makes it a little hard to 
> make out. If it can't be repaired where can I find a replacement? 
> I'm in the usa, Colorado to be exact.
> 
> Thanks, Synthflake
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links

on 3/26/05 10:10 AM, synthflake at gemjamstudio@... wrote:

> 
> 
> Ok, a closer look at the display and the backlight is working, just
> not nearly as bright as my Korg 03R/W and Yamaha TG500. Roland told
> me the $115 LCD is now discontinued and telesisbacklighting.com says
> they can't fix those but wanted me to check to make sure I was
> driving enough current for the backlight. Looking inside the unit
> there is a 1/4watt resister (axial) right next to the header where
> the LCD ribbon cable plugs in, I'm wondering if this may be a current
> limiter for the LCD backlight? Seems logical that in a mass of SMT
> devices a single precision 1/4 watter right next to the connector...
> Does anyone have a schematic of the JV880 that might show a LCD
> backlight intensity select resistor?
> 
> Synthflake

Okay. I have a schematic( or as some of my customers call a sketch-0-matic)
There is a resistor designated R116, one end tied to Vcc(+5 volt dc) and
the other tied to pin15 of the ribbon cable to the LCD. The schematic does
not give the
value(thanks, Roland). Get this, neither does the parts list, "describing"
R116 on main board, ERD2FCJ8R2P. I am guessing the value to be 8.2 ohms.
So should be easy enough to measure the value of the resistor you found.
If the display has only this one 16pin ribbon cable and also not a separate
2 conductor cable , chances are good that the backlight is not a EL type
but a LED type. Given this, pin 15 is where the LED's get their current.
To positively determine this, try lifting one end of R116; if the backlight
disappears, then that's it. Now then, brother, you are on your own if
want to change the value of it. If you do change it, advise conservative
value to 7.5 or 6.8 ohms. Also keep in mind that I deconstructed(guessed)
the value based on the part's list description, better yet to determine
the value by the color code. Good Luck. Russ

Russ,

Thanks for confirming. I pulled one end of the resistor, it is an 8.2 
ohm. Leaving that disconnected upon powerup the display had graphics 
but ZERO backlight. Monday I'll pick up a couple of resistors from 
work to try, or maybe a pot so I can adjust the brightness I want. 
I'll let you know how it goes.

Thanks again, Synthflake

--- In vintagesynthrepair@yahoogroups.com, Russ Rose <russrose@m...> 
wrote:
> on 3/26/05 10:10 AM, synthflake at gemjamstudio@h... wrote:
> 
> > 
> > 
> > Ok, a closer look at the display and the backlight is working, 
just
> > not nearly as bright as my Korg 03R/W and Yamaha TG500. Roland 
told
> > me the $115 LCD is now discontinued and telesisbacklighting.com 
says
> > they can't fix those but wanted me to check to make sure I was
> > driving enough current for the backlight. Looking inside the unit
> > there is a 1/4watt resister (axial) right next to the header where
> > the LCD ribbon cable plugs in, I'm wondering if this may be a 
current
> > limiter for the LCD backlight? Seems logical that in a mass of SMT
> > devices a single precision 1/4 watter right next to the 
connector...
> > Does anyone have a schematic of the JV880 that might show a LCD
> > backlight intensity select resistor?
> > 
> > Synthflake
> 
> Okay. I have a schematic( or as some of my customers call a sketch-
0-matic)
> There is a resistor designated R116, one end tied to Vcc(+5 volt 
dc) and
> the other tied to pin15 of the ribbon cable to the LCD. The 
schematic does
> not give the
> value(thanks, Roland). Get this, neither does the parts 
list, "describing"
> R116 on main board, ERD2FCJ8R2P. I am guessing the value to be 8.2 
ohms.
> So should be easy enough to measure the value of the resistor you 
found.
> If the display has only this one 16pin ribbon cable and also not a 
separate
> 2 conductor cable , chances are good that the backlight is not a EL 
type
> but a LED type. Given this, pin 15 is where the LED's get their 
current.
> To positively determine this, try lifting one end of R116; if the 
backlight
> disappears, then that's it. Now then, brother, you are on your own 
if
> want to change the value of it. If you do change it, advise 
conservative
> value to 7.5 or 6.8 ohms. Also keep in mind that I deconstructed
(guessed)
> the value based on the part's list description, better yet to 
determine
> the value by the color code. Good Luck. Russ

The subject says it all. Anybody have any leads on where i could 
get a pair of CEM 3340 VCO's and/or a pair of CEM 3360 dual VCA's?

--t
[london, canada]

--- In vintagesynthrepair@yahoogroups.com, Tim Glasgow <rorytate@s...> wrote:
> 
>     The subject says it all. Anybody have any leads on where i could 
> get a pair of CEM 3340 VCO's and/or a pair of CEM 3360 dual VCA's?
> 
> --t
> [london, canada]

Try Synthesis Technology www.synthtech.com. Also, there is a user on eBay, 'chipforbrains' 
that often has Curtis chips for sale.

You could also try US Bid, www.usbid.com, they have a lot of obsolete components, 
unfortunately they have a $500 minimum line order...

Tom