#1  
05-25-2011, 09:40 AM
Matt Fisher Matt Fisher is offline
Free Member
 
Join Date: May 2011
Posts: 1
Thanked 0 Times in 0 Posts
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
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Ads / Sponsors
 
Join Date: ∞
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
05-25-2011, 08:22 PM
admin's Avatar
admin admin is offline
Site Staff | Web Development
 
Join Date: Jul 2003
Posts: 4,310
Thanked 654 Times in 457 Posts
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.

- Did this site help you? Then upgrade to Premium Member and show your support!
- Also: Like Us on Facebook for special DVD/Blu-ray news and deals!
Reply With Quote
  #3  
11-13-2016, 05:39 PM
pishta pishta is offline
Free Member
 
Join Date: Nov 2016
Posts: 4
Thanked 0 Times in 0 Posts
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.
Reply With Quote
  #4  
11-16-2016, 12:04 AM
Tock13 Tock13 is offline
Free Member
 
Join Date: Nov 2016
Posts: 1
Thanked 0 Times in 0 Posts
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?
Reply With Quote
  #5  
11-18-2016, 03:24 PM
pishta pishta is offline
Free Member
 
Join Date: Nov 2016
Posts: 4
Thanked 0 Times in 0 Posts
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.
Reply With Quote
  #6  
03-20-2023, 09:58 AM
themaster1 themaster1 is offline
Free Member
 
Join Date: Feb 2011
Location: France
Posts: 497
Thanked 99 Times in 83 Posts
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 )
Reply With Quote
  #7  
03-20-2023, 01:26 PM
Eric-Jan Eric-Jan is offline
Free Member
 
Join Date: Aug 2018
Location: Netherlands,
Posts: 421
Thanked 56 Times in 51 Posts
Those fluorisent displays loose maybe also their vacuum ? or metal particles get vapourized
Reply With Quote
  #8  
03-20-2023, 04:33 PM
pishta pishta is offline
Free Member
 
Join Date: Nov 2016
Posts: 4
Thanked 0 Times in 0 Posts
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.


Last edited by pishta; 03-20-2023 at 04:53 PM.
Reply With Quote
  #9  
02-09-2024, 08:19 PM
npbrown82 npbrown82 is offline
Free Member
 
Join Date: Jan 2023
Posts: 3
Thanked 3 Times in 2 Posts
Though this forum post may be old, I'd like to contribute some insights for future readers encountering similar issues. First, I highly recommend watching an excellent video on repairing dim or dead vacuum fluorescent displays, like "Pioneer D-07 DAT dead vacuum fluorescent display repair." Although it focuses on DAT machines, there's significant overlap with VCRs. It's REALLY good!

Specifically, I work with JVC VCRs, but the knowledge can apply to various makes and models. Here are my recommendations:
  • Invest in Adobe Acrobat Pro for scanning and making text searchable, which is invaluable for troubleshooting.
  • Obtain the service manual for your device, make sure it has schematics (e.g. "Switching Regulator Main Schematic"), which you can find through online searches. Some of these service manuals out there don't have schematics, but luckily many do.
  • Utilize Adobe Acrobat Pro's "Poster" option to print out large-format schematics for easy reference. It's really easy with this to see how things flow, and what a culprit to. If you want to save trees, no problem, it just helped me to write notes and highlight elements of the schematic as I followed the path.
  • Pay attention to voltages; vacuum fluorescent displays typically require higher voltages (e.g., -29V some JVCs, look for large-ish negative -27, -29 and -31 numbers specifically). Once you find this start following the path these negative numbers follow, identifty diodes, resistors and capacitors in the parth that may be the culprit. In my case, it was a bad resistor - which meant zero display. But a bad capacitor may mean a dim display.
  • Watch the recommended video for effective troubleshooting techniques using the schematic. He explains it well and get it DAT machine running like a champ.

Hope this is helpful for future readers. Happy fixng!
Reply With Quote
The following users thank npbrown82 for this useful post: lordsmurf (02-14-2024)
  #10  
02-10-2024, 09:12 AM
pishta pishta is offline
Free Member
 
Join Date: Nov 2016
Posts: 4
Thanked 0 Times in 0 Posts
My display is just dim. Flashing 12:00 AM for 30 years for the PO probably did it in!
Reply With Quote
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
JVC HR-S8000U S-VHS VCR (looking for it's JVC original accessories) Tasuke Capture, Record, Transfer 49 07-10-2016 02:34 PM
Unable to get Flash vid to display in transparemt mode vidweb Encode, Convert for streaming 5 03-04-2011 04:56 PM
Fixing VHS tearing during capture; JVC D-VHS vs. JVC S-VHS VCR? lucgallant Capture, Record, Transfer 10 05-09-2010 07:15 PM
Fixing audio that comes out of one speaker Superstar Restore, Filter, Improve Quality 3 03-01-2010 12:13 AM
Interlacing display Question admin Videography: Cameras, TVs and Players 0 01-22-2009 07:47 PM

Thread Tools



 
All times are GMT -5. The time now is 06:33 AM