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#1
01-06-2023, 12:28 AM
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Bought another JVC HR-D470U..
Bought another JVC HR-D470U side loader. Bought it as dead / won't power on. Got into it and found a shorted cap and open resistor in the power supply. Replaced those and it's alive! I didn't think it would actually play without at least cleaning or replacing the belts and maybe lubing the mechanism. It actually plays pretty well. It doesn't struggle at all loading / unloading or changing modes. The VFD has some problems. Some segments are not lit up. I will have to look at that later on.
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#3
01-07-2023, 05:42 PM
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I have the Zenith version of this (or one of the Zenith versions) the VR-2300 and it had VFD issues as well. It was dim, and the VU meters only displayed when the clock was flashing 12:00, between the flashes, on dim mode.
One mine there's a regulator board that provides -30v to the VFD, and two capacitors were bad - a 22uf and 47uf. I'm assuming things in the D470 will be slightly different, but probably a similar issue.
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#5
01-08-2023, 09:18 AM
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Those old side loading VCRs are pretty neat. Got the lowest end Zenith version which is 4 head mono but on my Sony Trinitron from 85 it's fine as it's only mono seat. If I was you I would do probnot said and check for bad caps on the board for the VFD before you buy a kit as you caps are way cheaper especially if it's one or two that are bad.
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#10
01-08-2023, 10:44 PM
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Quote:
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#11
01-08-2023, 10:47 PM
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I looked at the faulty display hoping to find a high ESR cap or something obvious. I checked about 4 caps for ESR and they were OK. There is another PCB that 2 ribbon cables attach to. It also has 7 plugs going to it. It's a small PCB that also has the memory backup cap. Only the memory cap checked bad.
I had another same model VCR that has a very nice display but has no picture. I swapped the front display PCB and it was nice and bright but still missing the same segments as the original display. I went ahead and swapped the small PCB and guess what. It all works now! Still need a memory backup cap but the whole thing works! I hate troubleshooting like this but I was stuck. Now I need to go over the original PCB with a fine tooth comb. Ill bet it will be obvious when I find the problem.
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#12
01-08-2023, 10:59 PM
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Since you can't record of air anymore I would not replace the super cap as. I removed the super cap from my Zenith as they can leak and since I don't care if I have to reset the clock I left it out as doesn't hurt anything to leave it out. Also probnot made a video on his Zenith and he removed two super caps from his and left both of them out and one of them caps had started to leak.
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#14
01-08-2023, 11:42 PM
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The plot thickens...
I was looking at the failed circuit board. I noticed a diode (I think) that has been encased in a plastic insulator and soldered to the bottom side of the PCB. It runs from pin 5 of connector CN308 to pin 4 of connector CN302. It appears to have been hand soldered on. The schematic shows these 2 points connected. The original PCB trace has been cut. This looks like a factory modification. There is no continuity on diode test on my meter between the two points. I looked at the board that is working and there is no diode and it has continuity between those 2 points. I wish I had access to all service literature. I have the service manual, but I wonder of there are any service bulletins.
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#15
01-09-2023, 12:22 AM
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Quote:
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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