Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
Sharp TV 1984 model 20J81C - fuse blown.
SAMS Photofact should have a cross reference for your 20 year old Sharp TV.
The burning smell you refer to may be from the LOPT, Yoke, or other device within the set. Suspect possible problems within the deflection and power supply circuits. Main situation you may encounter is the availability of components for a set this old, especially from Sharp. IMHO. "derek" wrote in message om... The main power supply fuse has blown and I'd like to fix this myself if I can find the components at fault. It had a burning smell at the time it blew, however apart from the fuse itself I can find no signs of burned caps, diodes or resistors etc. I have tried to find a schematic in the library RCA guides but can only get one for model 20D74C, however this power supply schematic does not seem to be quite the same as my set. Does anyone know which guide number would contain my model(20J81C)? I have some electronics tech experience but am not a TV technician and lack any equipment such as a scope or variac supply; I do however have an isolation transformer - only 250VA, would this suffice? So far I have used the series light bulb technique; at first the lamp is bright but after a minute or so it dims and then starts on and off, about once a second with a clicking sound coming from either the main filter cap C706 (470micF) or the neighbouring HOT (T602). At this time the voltage across C706 rises from 40V to 80V - with the lamp still in series. Can anyone suggest likely components to test, and how exactly with only a VOM? In the meantime I'm off to buy a new set but still want to crack this! Reply only to the NG please. Thanks, Derek |
#2
|
|||
|
|||
Sharp TV 1984 model 20J81C - fuse blown.
The Sharps of this vintage had a big problem with high voltage transformers
going bad. My guess is the transformer is bad, shorting the horiz output transistor then blowing the fuse. Rom |
#3
|
|||
|
|||
Sharp TV 1984 model 20J81C - fuse blown.
derek said:
Thanks guys; regretfully I think you are right about the probable fault(s) and the impracticality of repair. It relates to that other post about the future of TV repair doesn't it - very sad. I hate this throw away society! Oh well - I'm not going to waste money on any rapidly obsolescing high-end product when I rarely watch TV. Thinking of a cheap Sanyo,Sylvania or something called Prima (Chinese I guess?) Derek Get a TV from a known brand like Sony, Philips... You will get more TV for what you spend. []s -- © Chaos Master. |"These wounds won't seem to heal Posting from Brazil. | This pain is just too real http://marreka.no-ip.com | There's just too much that time can't erase" (most often offline... ) | -- Evanescence, "My Immortal" |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
WARNING. DeWALT And Black and Decker Tools causing serious Injury and Death. | Woodworking | |||
Dewalt Recalls? | Metalworking | |||
Shopsmith bandsaw tires, no replacements for 1984 model. | Woodworking | |||
Micrwave oven - M8A fuse? | Electronics Repair | |||
Sharp TV model 27NS100 | Electronics Repair |