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screech in speaker when turning off set
So the Avante is acting up a little upon power off. Sometimes it makes a very short screech sound from the speaker when turned off and sometimes it's a bit longer. I'm not sure where to look on this one. It definitely is coming from the speaker.
Any thoughts? Thanks
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#2
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Check inside for owls...
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Let me live in the house beside the road and be a friend to man. |
#3
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Beats me.
See if it still does it with the volume down all the way. Also see if you hear anything amiss between words in a show. . That may narrow it down. If its a remote it could be coming from there also. BTW is this the set that had afterglow ?? If it is the two things may be related. That concerns me ( HV)........ 73 Zeno LFOD ! |
#4
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Quote:
As luck would have it, it's not screeching anymore, or at least for the moment. The set is cold now, so it might need warming up. I'll run it for a bit and check it again.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#5
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A weak/bad filter cap can cause this. It was pretty common on early RCA XL100's but can happen on others. Could be the source of your jail bars as well.
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Audiokarma |
#6
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Replaced all electrolytic caps on the chassis, but probably not on the sound board. I'll have to pull it and check.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#7
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The Crosley was still making that sound, IIRC, when we relegated it to the basement (where it stayed from the '60s until the early '70s). It never occurred to me that filter caps could have been causing the noise, although I was just starting out in electronics at the time and knew very little about underchassis repairs (most if not alll of my "repairs" in those days on the old TVs I would rescue from the trash were done by replacing tubes).
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Jeff, WB8NHV Collecting, restoring and enjoying vintage Zenith radios since 2002 Zenith. Gone, but not forgotten. Last edited by Jeffhs; 09-01-2018 at 12:57 PM. Reason: Spelling correction |
#8
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Well I found the cause of the screech. It's the darn volume pot. I have cleaned it so many times, but it never helped. There seem to be dead spots and other issues internally. I have to go back and forth several times to get the sound just right. So scratchy and dropouts as I turn it. I found the perfect position and all has been well, but I guess that spot wasn't meant to last for ever. It started getting muffled, so I tweaked it again and now it is clear and the screech is gone.
I've searched for over 5 years for a replacement pot (63-10263), but can't find one. Some day I will find one. Thanks for all the input, and if anyone knows where a volume pot can be found, let me know.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#9
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Quote:
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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 |
#10
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Quote:
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
Audiokarma |
#11
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If you find one with the right resistance and taps, I think it would be possible to swap out the shaft.
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#12
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Like Jeff said about his parent's Crosley, I have a '65 Sylvania BW set that does this too, as the raster shrinks to a small square and disappears. It always did and still does last time I checked.
Show a pic of that pot, I may have one. I scrapped a few similar chassis.
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"When resistors increase in value, they're worthless" -Dave G |
#13
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Shafts can be swapped on the same brand of pots, its easy.
Mounting style does matter. Twist tab, nut, plastic etc. Almost any VC from a flat chassis or hybrid should be the same ohms. The uprights may be also. Remotes may use a different value. Finding an NOS OEM pot is probably impossible. They were almost never changed, cleaning worked for years. Only exception is if it has an on/off switch. They were usually changed with OEM part due to switch failure. Last thing is be sure all the ground straps are well tightened. They should run from main chassis to CRT, convergence, tuners, secondary & primary controls etc. They are the heavy flat straps covered in yellow plastic. 73 Zeno LFOD ! |
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