Re: Should a transformer live/neutral pins have continuity?
Yea one side has been cut off
Yea one side has been cut off
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Re: Should a transformer live/neutral pins have continuity?
Lots of bad solder joints with crack ring on the solder around the components'legs.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Should a transformer live/neutral pins have continuity?
That is pretty shocking soldering, whwere do you see the ring fracture?Comment
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Re: Should a transformer live/neutral pins have continuity?
If you look at STK-XXX IC legs, you will probably see some there too.
When I work on these I always look through all the boards and redo the joints, and make sure all the board mounting screws are tight because the boards are GND to the chassis with mounting screws.Attached FilesNever stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Should a transformer live/neutral pins have continuity?
measured the two rubycons. One is measuring 48uF and the other 98uF so one deffo dead
Found one joint on the speaker terminals completely removed from pad taking pad with it
looks to be either a grounding or just a support pin perhaps.
Not impressed with the assembly of the unit, way too much flex in the board and nothing really secure.Comment
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Re: Should a transformer live/neutral pins have continuity?
i cant imagine cutting the side off a relay like that just to save a few coins!
some people are too cheap for their own good!Comment
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Re: Should a transformer live/neutral pins have continuity?
Alright changed the capacitors and that relay but still no luck.
Although I am getting some playback through the headphones but is very low volume and crackly.
Also when a speaker is wired in to the unit and I plug in the mains power cable the speakers makes a popping noise. Which is more than it was doing before.
Where should I explore next?Comment
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Re: Should a transformer live/neutral pins have continuity?
I'd start with the power amp finals circuit, check caps, resistors and fuses there.
Audio boards in general aren't made that well in my experience. Crappy solder joints and weak bond between traces and board are pretty common. Too easy to lift pads and traces with a little too much heat. They often aren't laminated and multi-layered like computer boards are so they flex more too.Comment
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Re: Should a transformer live/neutral pins have continuity?
Re-solder all of those joints budm pointed to, and possibly any others you find suspect. Generally, that would be all of the larger components or components mounted on a heatsink.
And wow! Who worked on that unit?! Did they by any chance use a hot chisel or something along those lines to solder? Amusingly terrible job at best!Last edited by momaka; 10-07-2015, 07:50 PM.Comment
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Re: Should a transformer live/neutral pins have continuity?
For testing, don't use speakers that you care a lot about. Normally a quiet amp will have near zero DC voltage output. A malfunction can cause it to output a significant amount of DC, which can destroy a speaker by heating up the voice coil.Comment
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Re: Should a transformer live/neutral pins have continuity?
Found 5 dead caps so far at the rear of the unit by the terminals
FRONT LEFT
jamicon 1 - 100v4.7uf @ 5.25uf
jamicon 2 - 100v4.7uf @ 5.33uf
nichicon 1 - 50v10uf @ 11.3uf
elna 1 - 50v0.47uf @ 468nf
rubycon 1 - 10v100uf @ 116uf
rubycon 2 - 10v100uf @ 113uf
jamicon 3 - 50v2.2uf @ 2.5uf
MID BOARD
elna 10v47uf @ 30uf
jamicon 10v47uf @ 15.5uf
nichicon 50v4.7uf @ 4.8uh
nichicon 50v4.7uf @ 4.9uf
rubycon 10v100uf @ 96uf
EXPANSION BOARD
not checked yet
REAR
jamicon 4 - 25v330uf @ 281.3nf
jamicon 5 - 16v470uf @ 23nf
rubycon 3 - 10v100uf @ 113uf
rubycon 4 - 10v220uf @ ...nf
rubycon 5 - 50v1uf@ 1uf
rubycon 6 - 50v10uf@ 11uf
jamicon 16v100uf @ 113uf
nichicon 50v47uf @ 53uf
rubycon 50v4.7uf @ 4.9uf
making some headway. Ive tried photographing where everything was and have kept caps separate in sections they were removed from but a bit worried I may misplace them when putting them back in. Does the service manual tell you locations of caps just in case?Attached FilesLast edited by mikay786; 10-12-2015, 04:48 PM.Comment
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Re: Should a transformer live/neutral pins have continuity?
So in total found a further 5 dead caps (along with 1 earlier), the rest seem ok. I'm using my multimeter which has capacitance tester built in so wont be the most accurate but should be fine to determine if bad or not. 2 in mid board and 3 at rear of board.
jamicon 25v330uf - Panasonic FR Series 330uF 25V - http://uk.farnell.com/webapp/wcs/sto...&storeId=10151
jamicon 16v470uf - Panasonic FR Series 470uF 16V - http://uk.farnell.com/webapp/wcs/sto...&storeId=10151
rubycon 10v220uf - Panasonic FR Series 220uF 10V - http://uk.farnell.com/webapp/wcs/sto...&storeId=10151
elna 10v47uf - RUBYCON ML Series 47uF 10V - http://uk.farnell.com/webapp/wcs/sto...&storeId=10151
jamicon 10v47uf - RUBYCON ML Series 47uF 10V - http://uk.farnell.com/webapp/wcs/sto...&storeId=10151
Are these replacements ok, chose Panasonic FR where I could but they didn't have much selection for the 10v47uf so had to choose rubycon ML Series. Will these do?Last edited by mikay786; 10-13-2015, 09:01 AM.Comment
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Re: Should a transformer live/neutral pins have continuity?
Usually general purpose caps are used for audio but those should all be fine.
When changing multiple caps I write down the circuit designation (ex. c1, c2, c3, etc.) which is printed on the board and the value and voltage of each cap as a guide.Comment
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Re: Should a transformer live/neutral pins have continuity?
use 16v 47uf then
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Re: Should a transformer live/neutral pins have continuity?
They (Farnel) having no FR FC FM in 16v either. They have 1 FC but not in stockComment
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Re: Should a transformer live/neutral pins have continuity?
so use 25v
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Re: Should a transformer live/neutral pins have continuity?
Didn't realise you could go that high
so is it safe to go as high as you want on V?
Anyhow replacement caps turned up nice and early, wish me luckComment
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Re: Should a transformer live/neutral pins have continuity?
I give up, still no joy. That's about as much time and money I want to spend on this thing.Comment
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Bear with me as this is getting interesting.
Not a lot as the saying goes but it may help someone to decide on throwing it in the landfill or rescuing it.
Symptom no go.
*******
WARNING THIS STUFF CAN BE FATAL IF WORKED ON LIVE. PLEASE DO NOT WORK ON THIS LIVE UNLESS YOU KNOW WHAT YOU ARE DOING
YOU NEED A GOOD VARIAC AND AN ISOLATING TRANSFORMER AND SKILLS. IF YOU DO NOT HAVE DONT TOUCH.
A LOT OF THIS CAN BE FAULT TRACED USING CONTINUITY METER ONLY.USE A 12V CAR BATTERY FOR THE MOTOR TEST WITH AN IN LINE FUSE. 10A.
I'LL RUN THROUGH THE CONTROL BOARD TEST... -
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Everything else was tested in circuit with a multimeter.
In circuit tests
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