Hello,
I gave an old headunit a second life in my Prius, but the brightness of the display is severely lacking. I tried to read up on it and have come as far that I (think I) know it is a VFD display.
I opened the detachable front up, but cannot find much info on the chips: PD6199 and PD6200 from Pioneer. The PD6000 range supposedly is a range of VFD drivers from Logiccontrols but even if there is a link between my Pioneer chips and the Logiccontrol ones, I haven't been able to locate the specsheets from my specific chips.
I tried reading up on how the intensity/brightness is controlled and this could be DC, PWM or AC. One thread says the displays get old and there's nothing you can do, the next claims it's aging of the driving components that is mostly the issue. 😕
Some claim the filament needs a 1V voltage, but what I think it the filament connection has HIGH VOLTAGE printed besides it (to the far left of the rear-side of the PCB)
So in short: I'm in over my head. Any info will be greatly appreciated.
The headunit: DEH P835R. PCB on which the VFD is mounted: CNP4962-A.
Two ~80 pin chips: Pioneer PD6199A and PD6200A, productiondate 9833 and 9838.
Edit: here's a pic (not mine) of the display. And yes: it is a dimmable display, but I switched off the dimming and it is the brightest setting that is not nearly bright enough to read during the daytime.
I gave an old headunit a second life in my Prius, but the brightness of the display is severely lacking. I tried to read up on it and have come as far that I (think I) know it is a VFD display.
I opened the detachable front up, but cannot find much info on the chips: PD6199 and PD6200 from Pioneer. The PD6000 range supposedly is a range of VFD drivers from Logiccontrols but even if there is a link between my Pioneer chips and the Logiccontrol ones, I haven't been able to locate the specsheets from my specific chips.
I tried reading up on how the intensity/brightness is controlled and this could be DC, PWM or AC. One thread says the displays get old and there's nothing you can do, the next claims it's aging of the driving components that is mostly the issue. 😕
Some claim the filament needs a 1V voltage, but what I think it the filament connection has HIGH VOLTAGE printed besides it (to the far left of the rear-side of the PCB)
So in short: I'm in over my head. Any info will be greatly appreciated.
The headunit: DEH P835R. PCB on which the VFD is mounted: CNP4962-A.
Two ~80 pin chips: Pioneer PD6199A and PD6200A, productiondate 9833 and 9838.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Edit: here's a pic (not mine) of the display. And yes: it is a dimmable display, but I switched off the dimming and it is the brightest setting that is not nearly bright enough to read during the daytime.
An externally hosted image should be here but it was not working when we last tested it.
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If its a VFD (and I can't tell from the pic) then the filament will be the end pins (one at each end). Also the display will be warm (the filaments) and you can often see the filaments glowing in the dark.
VFD's of the type I'm used (displays in DVD's VCR's etc) do age and deteriorate.
To be honest yours does not look like this and seems more of an "electroluminescent display" type, a different technology.
Experience says the chips won't be at fault (unless there is a recognised stock problem) and that the problem will be either the display or the voltages it needs and being an electroluminescent would explain the high voltage markings as these panels do need a couple of hundered volts.
http://www.planarembedded.com/elect...el/assets/Electroluminescent-Displays-FAQ.pdf
VFD's of the type I'm used (displays in DVD's VCR's etc) do age and deteriorate.
To be honest yours does not look like this and seems more of an "electroluminescent display" type, a different technology.
Experience says the chips won't be at fault (unless there is a recognised stock problem) and that the problem will be either the display or the voltages it needs and being an electroluminescent would explain the high voltage markings as these panels do need a couple of hundered volts.
http://www.planarembedded.com/elect...el/assets/Electroluminescent-Displays-FAQ.pdf
If it is, I've been reading up on the wrong technology 🙂
From your link:
That has some perspective!!! Biggest problem is measuring while it is hooked up... 🙁
Am still readiing...
Edit... you are correct: just found this: (frontpage of the service manual mentioning EL and the 200V supply it uses...)
From your link:
That has some perspective!!! Biggest problem is measuring while it is hooked up... 🙁
Am still readiing...
Edit... you are correct: just found this: (frontpage of the service manual mentioning EL and the 200V supply it uses...)
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There is a small square enclosure attached to the back of the unit. That's the inverter/power supply for the EL backlight. You should open it and see if there is any damage. In the older units, there was always thermal damage (bad solder connections, leaky caps, weak/leaky transistors).
The service manual warns that the voltage is ~200v AC so be careful when handling it.
The service manual warns that the voltage is ~200v AC so be careful when handling it.
Thanks! I have downloaded the service manual and the dimmercontrol (the output on the main processor that dims the display when your headlights are on) seems to send a signal to the high-voltage generator, leading me to think the AC voltage IS the brightness-control. (For someone familiar with the technology that might be an open door, for me it's a big step in understanding where to look).
And thanks for the warning but I (famous last words...) know what I am doing 😛
Edit: the inverterunit is a strange beast, it only has one in and one out (and two grounds) according to the schematic. That might suggest it gets either 12V or e.g. 8 volts for full brightness and dimmed brightness respectively (and the inverter acts as a dumb transformer with a fixed set of windings). Will examine that some more.
And I'll have to remove the whole radio 🙁 Which means ripping up the whole dash again... (Prius means it is screwed into a frame, not just slid into a cage to be removed with just two keys). So be it.
And thanks for the warning but I (famous last words...) know what I am doing 😛
Edit: the inverterunit is a strange beast, it only has one in and one out (and two grounds) according to the schematic. That might suggest it gets either 12V or e.g. 8 volts for full brightness and dimmed brightness respectively (and the inverter acts as a dumb transformer with a fixed set of windings). Will examine that some more.
And I'll have to remove the whole radio 🙁 Which means ripping up the whole dash again... (Prius means it is screwed into a frame, not just slid into a cage to be removed with just two keys). So be it.
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Unless you have a different manual, I couldn't find an internal schematic for the inverter so I think you're left to general troubleshooting techniques.
The dimming circuit seems like it may just send less voltage to the inverter so that it produces less output voltage. Confirm that you have the right voltages on Q803 with 12v applied and not applied to the dimmer/illumination wire.
The dimming circuit seems like it may just send less voltage to the inverter so that it produces less output voltage. Confirm that you have the right voltages on Q803 with 12v applied and not applied to the dimmer/illumination wire.
I just went up and down the manual several times, but I cannot find the inverter schematic either.
Thanks again for the input, will check this (both the inverter's parts and soldering and the bright/dim voltages). As a simple solution I could e.g. lower the 2W 100 ohm resistor (R804) but I'll look for bad parts/soldering etc. first.
But I am somewhat thrown by the values. 5.8V (bright) or 3.9V (dim) which then goes through 100 ohm before entering the inverter.
So less than 40mA. Assuming half the voltage does reach the inverter (~2V and 20mA for the dimmed light) means the light of the display is just 0.04W. Seems very low, but maybe I just don't have a feel for it...
Will update if I find a solution.
Thanks again for the input, will check this (both the inverter's parts and soldering and the bright/dim voltages). As a simple solution I could e.g. lower the 2W 100 ohm resistor (R804) but I'll look for bad parts/soldering etc. first.
But I am somewhat thrown by the values. 5.8V (bright) or 3.9V (dim) which then goes through 100 ohm before entering the inverter.
So less than 40mA. Assuming half the voltage does reach the inverter (~2V and 20mA for the dimmed light) means the light of the display is just 0.04W. Seems very low, but maybe I just don't have a feel for it...
Will update if I find a solution.
Remove the display aluminum trim and change the EL folie behind. You can get it here:
Electroluminescent foil White(L x W) 138 mm x 34 mm60 - 110 V buy now - Conrad Electronic SE Displays-backlight, framework Electronics Online Store
You might need a different size, just measure before ordering.
Worked very well on my old dex-p99r.
Electroluminescent foil White(L x W) 138 mm x 34 mm60 - 110 V buy now - Conrad Electronic SE Displays-backlight, framework Electronics Online Store
You might need a different size, just measure before ordering.
Worked very well on my old dex-p99r.
An externally hosted image should be here but it was not working when we last tested it.
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Was it a straight swap? Looks good!
Voltage seems much lower (70-110V) than mine (200V).
Currently making a relaybox for the trailerhitch first, but this is quite high on the list of things-to-do, so will update a.s.a.p.
Voltage seems much lower (70-110V) than mine (200V).
Currently making a relaybox for the trailerhitch first, but this is quite high on the list of things-to-do, so will update a.s.a.p.
Yes nearly, had to trim the edge on the EL to make it fit nicely. I do belive all the HU in this series have the same voltage.
The original EL made my display look dark green.
While you´re at it, remember to change the display ribbon cable.
To remove scratches I used the liquid from a Disc repair pro set:
XINIX Repair Refill Kit CD/DVD/Game Disc Repair Pro NEW | eBay
Just be careful as it removes the lettering also. Best I´ve tried so far.
The original EL made my display look dark green.
While you´re at it, remember to change the display ribbon cable.
To remove scratches I used the liquid from a Disc repair pro set:
XINIX Repair Refill Kit CD/DVD/Game Disc Repair Pro NEW | eBay
Just be careful as it removes the lettering also. Best I´ve tried so far.
Thanks Patrick, but how? With the new back-light-foil?
The HU will be replaced by a 2-din 7" JVC shortly, but I still intent to fix it 😀
The HU will be replaced by a 2-din 7" JVC shortly, but I still intent to fix it 😀
Was there any conclusion to this? I've had my 835 for 15 years and I love the thing. Been in 2 cars, a friends car on loan, then a MAME arcade cabinet, now a 3rd car of my own. That being an 06 civic. But something weird is going on with the screen. When I first got installed it was fine. It was at night but it was plenty bright, now the first time I drove it during the day I couldn't see the thing at all. Now it has faded down to almost nothing within a matter of days. The dimmer was working fine so far as I could tell, but only the screen and not the button backlighting.. I honestly can't remember if it was all supposed to dim or not. The only thing odd was the button backlighting would come on with the key on and radio off. I'm assuming the DRL somehow. I wired the + switched dimmer into the illumination wire like any older car would have so I don't understand what happened 🙁 Is this foil thing a miracle cure?
O well .. yesterday i was working on one similar. Can't find any where the vdf element.but digging into my old units find one jvc isn't vdf was led background lights. Have to cut the deflection screen but looks almost new. Using the same smd leds with some light blue filter between the white leds and deflector. Not too easy job but worth the effort.
@niqht:
The radio is still in the car and I haven't taken it out yet. So no conclusion whether it is simply replacing the resistor...
If I remember, I will try to see if the buttons dim too with the headlights on. The screen definitely does, but you knew that already.
The relacement with the 7"JVC didn't happen cause the wife called dibs (it's in our other car) and the other 7" JVC I have doesn't have USB (my telephone carkit does and I use its line-output into the AUX of the Pioneer right now, but that carkit is a piece of crap of which the remote isn't working 80% of the time)
I did loose my harddrive since writing the original thread, so I have lost dozens of service manuals (including for the Pioneer) and other info for projects... 🙁
The radio is still in the car and I haven't taken it out yet. So no conclusion whether it is simply replacing the resistor...
If I remember, I will try to see if the buttons dim too with the headlights on. The screen definitely does, but you knew that already.
The relacement with the 7"JVC didn't happen cause the wife called dibs (it's in our other car) and the other 7" JVC I have doesn't have USB (my telephone carkit does and I use its line-output into the AUX of the Pioneer right now, but that carkit is a piece of crap of which the remote isn't working 80% of the time)
I did loose my harddrive since writing the original thread, so I have lost dozens of service manuals (including for the Pioneer) and other info for projects... 🙁
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I just replaced the ELD from my DEQ7600 DSP as it was way faint. It's brighter than new now.
I'm using a large A3 sized panel where I cut the necessary size from and attach the corresponding adhesive ribbon connectors.
I already repaired several ELD displays this way.
A tip: as the phosphorus in the ELD panel is highly subject to humidity, I recommend covering the 4 edges with transparent scotch tape to stop it from entering. This will extend the life of the new panel.
I'm using a large A3 sized panel where I cut the necessary size from and attach the corresponding adhesive ribbon connectors.
I already repaired several ELD displays this way.
A tip: as the phosphorus in the ELD panel is highly subject to humidity, I recommend covering the 4 edges with transparent scotch tape to stop it from entering. This will extend the life of the new panel.
I know this thread is old, but I need some help and reading this article, you guys know what youre talking about.
I also have a Pioneer dehp835r, which I refuse to replace and throw it away (in my opinion, these older Pioneers HU are the most elegant, new HU seems to me simply childish, with all those lights, buttons, chrome trims etc... I like these old school Pioneers!).
Anyways, my radio works perfectly, doesnt have a single scratch on it, but the panels backlight is, as you may think, weak.
Question; what should I do? which is the correct part I should buy? Should I throw the panel away and get anotherone?
Please, any input will be welcome!!!! Let me know if you need further information!
Thanks a lot
I also have a Pioneer dehp835r, which I refuse to replace and throw it away (in my opinion, these older Pioneers HU are the most elegant, new HU seems to me simply childish, with all those lights, buttons, chrome trims etc... I like these old school Pioneers!).
Anyways, my radio works perfectly, doesnt have a single scratch on it, but the panels backlight is, as you may think, weak.
Question; what should I do? which is the correct part I should buy? Should I throw the panel away and get anotherone?
Please, any input will be welcome!!!! Let me know if you need further information!
Thanks a lot
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