the reason why i cant determine the fuse vale is because the tip of the fuse is burnt so bad i cant read the vale... and i know the IC are fine because i cheeked them. Why would i pots a thread on this forum if i know what the value if the fuse was. i can read... and i am a technician.
To the "Anonymous" person that was so rude … next time put your name on the board.
Scoring disabled. You must be logged in to score posts.
The pcb board is usually labeled with the fuse rating right next to the fuse.There is no such thing as a "horizontal IC" so I also believe your not a tech.
Also I think everyone who posts should post their name and not anonymous.
Sidney
Dartmouth,Nova Scotia
Canada
Scoring disabled. You must be logged in to score posts.
Yes pcb board is usually labeled with the fuse rating right next to the fuse, but the fuse holder and the surroundings of it even the pcb board is burnt. I can’t read any values on the fuse or the board. The tv is not mine fixing it for someone else, don’t know if the tv had a power surge through it since the flyback ,fuseholder and surroundings are burnt. And also I call it the “horizontal ic” it should be call the horizontal output transistor or “HOT”. And yes I am a tech, if not I wouldn’t be stupid enough to open a tv and play around with it. And Sidney, thanks for your input, you have help me in the past before.
Scoring disabled. You must be logged in to score posts.
if the board is burn't as bad as you say, then it sounds like somebody has put in a high amp fuse in it and has caused a lot more problems. the correct amperage fuse will blow instantly when ever a short is detected, and not cause further damage such as burning the board. usually most tv's take a 3-6 amp fuse. i would check the bridge rect, and any mov's, & diodes, for shorts, and then try a 5 amp fuse to see what happens. i assume this fuse is located in the primary side. good luck
Scoring disabled. You must be logged in to score posts.
Typically it is a 5 amp GMA style if it is the line fuse. You probably have something shorted in the primary side of the SMPS. Take a 100 watt lightbulb and connect it across the fuse holder. If it lights bright, you have a short. Check the rectifiers and the switching transistors.
Dave
Scoring disabled. You must be logged in to score posts.
i dont agree. A fuse has very low resistance so does not run hot. The only way the board is charred around the fuse is if the fuse holder was dry jointed or slack. I often think that common sense and a bit of thought answers a question without the need for some degree in physics, who on this planet has seen a good fuse run hot or does no one remember ohms law V=IR or the triangle with v on top and IR below, put your finger over 1 symbol giving you what it equals.
Scoring disabled. You must be logged in to score posts.
Rob, are you disagreeing with me? You are correct that a fuse should not run hot because of zero resistance. But I use the lightbulb trick in the customer's home all the time. It is quite the useful tool for the field electronics technician when interpreted properly. Dave
Scoring disabled. You must be logged in to score posts.
Yes I do disagree, to charr the board takes time, the fuse had to be hot for that time, where is there rocket science in that.
Sure as it flashed and banged other things may fail but the origin of this fault was a bad fuse holder.
Scoring disabled. You must be logged in to score posts.
My experience with the CTC169 chassis is the 3 electrolytic caps (C4108,C4102 & C4104) in the SMPS power supply fail and take out the controller IC (U4101V) which destroys the chopper transistor (Q4101) then the 5 amp line fuse blows (F4005),so read below for complete details:
From my repair experience on this CTC169 chassis which I hate here are common replacement failure parts:
Note:when it comes to Sony & RCA ALWAYS USE OEM #'s or the exact generic #'s when it comes to semiconductors but for electrolytic caps you can use any replacements.
Sydney is correct on this post. When I worked for Montgomery Ward Service, I carried those parts on the truck. The cap (C4102 I think) would fail and cause a cascade failure of the controller IC, the chopper xstr, the 3 watt zener and then FINALLY the line fuse would blow! It is quite a fond service memory. We rebuilt quite a lot of those 169 chassis.
Scoring disabled. You must be logged in to score posts.
You do not answer the question of why the fuse burnt to a state that it charred the panel. Sure the set may have issues but did these issues just blow the fuse or did the fuse go into simmer mode for several days. I have fixed TVs since the days of spot wabblers, heptodes pentodes and the like. I have yet to see an issue cause a fuse to char the panel that was other than the fuse or the holder. If your science is better than mine, please explain your theory. You can though accept ohms law that if R =0 then volts drop is zero as such there is zero energy expelled and zero heat. As everything has resistance at room temperature, then this will be incorrect by a fraction of a degree.
This surely is basic stuff, we are not into issues of string theory or the time differential in a black hole. I await replies
Scoring disabled. You must be logged in to score posts.
Since you are a tech, is this your own TV or did a customer bring it to you this way?
I've seen some customers install an automotive style 30amp fuse in where a standard low value fuse should go...heck, I've even seen aluminum foil wrapped around a bad fuse and then reinstalled.
Or another scenario, the original fuse blows, the customer removes the bad fuse and installs an over-rated fuse and then experiences a catastrophic event. Then the customer pulls out the over-rated fuse and reinstalls the original defective fuse and drops it off at your shop...claiming ignorance of course!
Scoring disabled. You must be logged in to score posts.
Why will no one answer the question, I dont care if someone fitted fence wire my question was what caused the board to char. What is writen as the reason for the failure does not comply with the origional, now he gives it as a bad AC socket which arcs. The back emf will kill the fuse but not char the panel, so my frustration grows, seemingly no one can get facts correct.
Scoring disabled. You must be logged in to score posts.
Sorry for getting back so late but I just got back from vacation, the problem was with the ac power socket. Since the power cord is not hotwired into the circuit (just a plug in like a computer monitor) there was a lose connection in the ac power socket. With the case off I jiggled the cord and I saw blue sparks in between the two points of the fuse connectors. Once I did that the fuse blew, after I replaced the fuse I did it again but this time I didn’t jiggle it so much. The fuse did not blow this time but blue sparks were still there so I replace the ac power socket and not it’s fine. The fuse was a 5a 125v fuse.
Scoring disabled. You must be logged in to score posts.
May I have your attention please?
May I have your attention please?
Will the real Ganges Man please stand up?
I repeat, will the real Ganges Man please stand up?
We're gonna have a problem here..
I'm the Ganges Man, yes I'm the real Ganges
All you other Ganges are just imitating
So won't the real Ganges Man please stand up,
please stand up, please stand up?
Scoring disabled. You must be logged in to score posts.
You are not a man !
How old are you ? Grow up & stop wasting a valuable website resource for mature adults such as myself who are fully capable of repairing our own electronic equipment. You obviously cannot !
Scoring disabled. You must be logged in to score posts.
