Tips on fixing JVC HR-S8000U dim VFD display?

Matt Fisher · #1 05-25-2011, 09:40 AM

Hello,

My S8000 front panel display gets gradually dimmer as you go from right to left. I've read variously that this is a problem with dirt or leaky caps on the power supply board. Anybody have any tips on where to start? I have basic soldering skills but am not able to really read schematics. Should I just go through and replace all of the electrolytics I find on all the boards? Thanks in advance!

Matt

admin · #2 05-25-2011, 08:22 PM

The most obvious method is to simply look for bulged or leaking caps -- possibly even caps that simply look odd.
Then replace them.

It's really not any different than the methodology used to repair JVC DVD recorders.
And we've archived quite a bit of info on that topic here: http://www.digitalfaq.com/forum/home...g-jvc-dvd.html

So open it up, and see what you can see.

pishta · #3 11-13-2016, 05:39 PM

Me too, but the thing is I unsoldered and checked EVERY cap (>13) on the power supply with a capacitor meter and only found 2 small light green 22-50Vs that were out of spec (15uf and 12uf) so I replaced them with spot on 22uf AL caps and there was no change. I have all on order (<$10.00) so Ill get in there and replace them all again which is no small job but I at least have all the sockets retainer tabs pre-broken(!) for the small 24g wires that come off the P/S. They mounted them so the tabs were inboard so you cant push them in to release....I checked the display board voltage and got -30V AC coming in on the red wire only.

Tock13 · #4 11-16-2016, 12:04 AM

Hi, I just bought one of these for a good price and have the same issue with the display. I am not seeing anything obvious on the boards could it be the actual display is bad? Is that very common with these types displays?

pishta · #5 11-18-2016, 03:24 PM

Yes, I am getting the feeling the displays are just worn oit, or maybe more accurately described by another poster as oxidized and in need of a burn off by a high voltage across the filamant/cathode like the internet shows. Do a youtube search for vfd burn up and you'll find a guy that does about 6 in 10 sexonds. Trouble is I don't know what kind of power he is using as I tried a 12v 8ah ups battery across the filament and didn't get anything glowing...? You may be able to fashion a new display with another vrs display that has similar symbols but you'll be breadboarding it big time. I recapped a Sanyo vcr and it totally fixed it's display but not this time.

themaster1 · #6 03-20-2023, 09:58 AM

I know it's a late reply but take a look at this video: The VFD don't work (or very dim), the ESR testing is useless in this case. Turns out a capacitor is shorted.

https://www.youtube.com/watch?v=tcWQ...nn8iFw&index=1
(by 12voltvids, Technics STS 707 Dim display repair )

Eric-Jan · #7 03-20-2023, 01:26 PM

Those fluorisent displays loose maybe also their vacuum ? or metal particles get vapourized

pishta · #8 03-20-2023, 04:33 PM

Ill check those Caps that supply the VFD the high voltage.I checked the display board voltage and got -30V AC coming in on the red wire only. This VCR is literally wall to wall through hole components on multiple stacked boards so its gonna be a challenge to find them. Pretty far back in the load for stuff I'm looking at repairing.