#1
|
|||
|
|||
1958 Silvertone no picture help?
Hi. I have have a 1958 Silvertone suburbanite. All working tubes and everything hooked up right. Has a full glowing screen but will show no picture. Does anyone have any idea why? I’ve ordered the schematics for this set they should be here In a few days. Any ideas please let me know.
|
#2
|
||||
|
||||
Have you replaced the electrolytic and paper dielectric capacitors?...That is a must on tube gear as the originals have failed or will fail and when they do they can take out other parts that are much MUCH harder to find.
If it has been recaped do you have a proper analog RF NTSC signal source and have you confirmed it works on a newer (80s to present) working TV? If those things are good have you cleaned the contacts in the tuner or tested tubes in the tuner IF and video stages? If that is good wiggle tubes in the order of video output, video amp (if there is one between the detector and output), highest number video IF down to lowest, then tuner....when you wiggle (you may need to pull from socket and reinsert) a tube you should get disturbance to what sounds like a blank raster. The area between the last tube to cause disturbance and the first one not to is the trouble spot. Another possibility is if the AGC pot is set too low....too low and you get no signal as you increase you get more signal till the sync separator overloads and sync is lost audio buzz and negative picture sometimes accompany that. Correct AGC adjustment is turn up till it starts to overload then back down just a bit below the overload point...If you touch the AGC, mark it's current position first so you can go back to it if needed. I can expand on any of these topics if you want/need.
__________________
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 |
#3
|
|||
|
|||
I have yet to put in new capacitors. I will not power tv back up as I do not want to damage parts. I have a schematic on its way here. Everywhere I read it seems very complicated. I’m sure I can figure it out but the risk of shock is frightening. What does one do to clear the power out of a television set? I can’t find this kind of repair man around Boston so I’m all I have. But yes capacitors are top on the list of first things to do. All tubes are working and in fine order.
|
#4
|
||||
|
||||
B+ is dangerous but it usually dissapates within a minute or two of unplugging the set. HV to the CRT is around 20KV with usually less than 1mA max...A static shock from shuffling on carpet and touching a door knob can be as much as 35KV and similar current/charge.... I've taken both multiple times and am fine...the worst part is what your reflexes cause you to smash into. If you take care to work with the set off and short any Electrolytic capacitors and the CRT HV line (place a 1M resistor in series to prevent dielectric charge bounce back) to ground you won't get zapped.
When working with the set powered avoid touching wires.connected to the flyback, yoke, and HV, work with one hand in your pocket and rubber soled shoes and avoid touching grounded objects with anything but your one hand not in your pocket. Voltage is not dangerous (though higher voltage facilitates current flow) current is dangerous 30mA=0.03A across your chest is enough to kill.... avoid current flow through your chest. AC is more dangerous than DC...DC will reset heart beat when you touch it but you will continue to move and have a heart beat while holding it assuming non leathal current flow. AC will will prevent your heart and muscles from functioning normally...the transformer, if it uses a power transformer,or power cord end B+ rectifier and anything connected to the power cord (series string tubes?) Is the most dangerous area. Most servicing especially the recap can be done with the set powered off... Just to be clear a tube lighting does not mean it is good... just that it is not dead in an obvious way. A tube can light but have no cathode emission or have inter-element shorts that make it non-functional in circuit. You should test your tubes in a purpose built emission or better yet mutual conductance type tube tester (they made cheap heater only tube testers but those are as unreliable as eyeballing for heater glow).
__________________
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 |
#5
|
||||
|
||||
Is your set the 21 inch model 8114?
I have one given to me by another one of my remote (none are local) TV repair colleagues without its CRT and I just found a donor set
__________________
"When resistors increase in value, they're worthless" -Dave G |
Audiokarma |
#6
|
||||
|
||||
Quote:
Remember also that today's TV signals are all digital, so connecting an antenna directly to your set absolutely will not work unless there are still one or more analog TV stations in your area (very unlikely in this day and age although some cities, such as Chicago, still have at least one analog VHF station currently on the air). Once you get your Silvertone console TV working, it will probably keep going for years to come, with a cable box or DTV converter. BTW, when you mentioned the year, manufacturer and model name of your TV, it immediately rang a bell in my head. I had a neighbor, now long since deceased, in my home town who owned a late-'50s Silvertone b&w console TV, possibly very similar to yours. She replaced it years later with a color set, so the old one gave her many years of good service. Those old TVs, unlike today's flat screens, were built to last 15-20 years or even longer; unfortunately, we will never see the likes of those days again.
__________________
Jeff, WB8NHV Collecting, restoring and enjoying vintage Zenith radios since 2002 Zenith. Gone, but not forgotten. Last edited by Jeffhs; 07-11-2020 at 03:42 PM. |
|
|