Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: scooby-doo on August 06, 2011,16:44:44
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I have just screwed up, bought a repair kit for the Logik LXW32HD1 "Blowing Fuses" fitted all ok, it stopped blowing fuses but I am not getting any voltages.
In the description where I bought the kit, it did mention to test the Standby transformer(16es-x03), I decide to do this now and found it's fluffed.
What can I do? is there an alternative. please dont say rewind it, I will fluff it up.
Thanks for any help
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hi
is it t20? or t21? try ohmsupplies they stock them i believe it is the
5volt supply
dave
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Dave is right, it is a 5v stand by transformer however its not available as a separate item.
The damage to is was caused by U2 blowing, it doesn't short internally but blows the wire from one of the legs to the windings. Its simple if a bit tricky to repair but I can instruct you how,
Where did you buy the kit from?
Regards
Andy
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Cheers Andy/Dave
It is the standby 5 volt transformer T4, I can see which leg is blown as the yellow tape is burnt and so is the board by one of the pins.
Sorry Andy went to your competitor CHS :c023:
Should of bought the bits individually as it was only three parts of the kit that were blown, U2 DB1 and T4...which is not included.
I am going to have a look now to see if I can have a go at fixing the transformer if I get stuck I will give you a shout.
Thanks anyway
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Bloody hell that is a little fiddly, getting a reading from the pins now so just going to fit and see, will let you know how it goes.
Thanks again,
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i cut the tape so i can see the wire on the coil then "loop" the leg and re-attach,
there will be a shortened version of this kit released in the next week or so, kit/kt number 15something, it will have less parts and therefore cheaper, but will have an additional part or 2.
With just the board switched on and upside down (so you can see the track undernieth) put your meter on the 2 points above c55 so you can check your repair before fitting it into the set
regards
Andy
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I think I have screwed this transformer up now :oops:
The wire has snapped and I haven't got anything to solder too.
Back to the drawing board on this one.
Thanks for all your help
Will the new kit include the transformer???
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Sorry, the part is not available as an individual item as it seems to be unique to this board, stand by transformers can be quite expensive to buy individually and to have them made would need a min. order of between 3,000 and 50,000 (we enquired on one once)
If you gently cut away some insulation without cutting the core, loop round the leg, tin both ends then solder together it should be repairable. Of all the ones I’ve done I’ve never know the wire not to be retrievable,
regards
Andy
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Andy cheers, you have obviously never worked with a clumsy bafoon like me.
I have just had a result and bought a faulty PSU for a tenner. with two more cracks of the whip I should get it right. Fingers crossed
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i'd say its 1 in 20 that the tx is damaged, it depends which way the fsd blows, upwards or sideways etc.
Andy
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Hi S/D,
No-one has yet said what PS is used (Guess it's Profilo with that FSD200 that just pops for fun and our profit)
If so, might well have a 'TR 20' S/by tranny - few become O/C - Chris.
PS - if not Profilo - what is it ?
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Hi
It is the Amoi PSU. FSD200 was quite badly burnt around a couple of the legs it also took the bridge rectifier on the underside out too.
Should have the second hand board tomorrow so hopefully will be sorted.
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From.memory the tx is made by tdk. Amoi normally manufacture much smaller supplies and as far as I know,none of the transformers on this board are available new. It does the same job as tr20 and to be honest if it was physically further away from the fsd200 it would be ok.
Regards
Andy
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Hi
Finally took delivery of the board today, fitted the transformer, seems to be a problem
@Andy: What readings should I be getting from the places you mentioned.
I fitted the PSU to the TV and when you turn it on all that it does is all the control lights and the red led start flashing no sequence just repetitive flashing.
Any help appreciated
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Hi
Got the flashing lights sorted, I had put U4 in the wrong way round, all I am getting now is a standby light no power etc etc.
Thanks again for any help
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Hello,
Was there info. on the backer reminding you about the opto? do you now have 5v after the tx?
regards
Andy
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If you do have 5v, try using the remote (that looks a lot like a Panasonic, doesn't it? :) )
regards
Andy
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Hi Andy
Thanks for the reply, I did try the remote with no joy.
I also took the parts (u2, c22 & db1) and put them into the damaged board I bought from flebay, this gave exactly the same fault....Could there be a chance that I have blown FSD200 again as I initally put U4 in the wrong way round? Putting it the wrong way round gave me all the flashing control panel lights.
Thanks for any help in advance.
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Hi
I have answered my own question and put another (know to work) fsd 200 in and the tv is still the same, the standby light seems to be very dull..
Is there anyway of checking the remote is working correctly?
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Was it on the backer about the opto or can you tell me the optop type?
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Sorry to sound Dumb Andy, I do not understand what you mean.
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U4,
What type is fitted (the markings on top) and did the backer that came with the kit say anything about U4?
Andy
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Hi
Its a sharp PC817,
I have just checked some of the voltages and I am getting about 3v from the 5v pins and 1.6v from the 3.3v pins, if that helps any
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did the backer that came with the kit say anything about U4?
turn the board over with just the supply and tell me the voltage on the 2 points in between C55 and C45. just that voltage please
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Hi
I am getting 5.10v from the place you mention
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Good,
did the backer that came with the kit say anything about U4?
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No mate I cant say I remeber seeing anything about U4, I didnt change U4 from the board that I got from Flebay. Andf I am getting exactly the same fault
Just to add that if I turn the board back over and check the voltages from the 10pin connector to the right at the bottom of the board this is the readings I get
GND=0v
5VM=0v
GND=0v
5v=0v
GND=0v
12v=0v
-12v=0v
GND=0v
5vs=5.10v
STB=1.8v
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If you have 5v from the point I gave then the orignal fault of a blown 5v supply and the tx problem is solved. If the opto (information is on the backer) was the wrong way round them 15v has gone down the 5v line and onto the scaler board, it depends on what its damaged its done however it doesn't always damage the board enough to make it B.E.R. but sometimes the front button set won't work,
Did you get the board from fea-bay or the whole set?
Andy
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Hi Andy
I have the original board and the board I have from flebay.
After I screwed up the original board I removed some of the new parts and fitted them to the flebay board, this did not include changing U4 so the flebay board has still got the original U4 in it as I thought I might of blown this too by putting it in the wrong way round in the original board
Do you think I should change U4 on the flebay board, and can I interchange it with either U5, U7 off the original board.
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Getting a bit confused now,
Has a psu been in the set and switched on with the opto the wrong way round?
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Hi Andy
Yes it has been turned on with U4 the wrong way round, this is when I got the flashing control panel lights, turned it back round and now I just get the very dim standby light, since my last post I have replaced U4 and still have the same fault.
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I'd think that the scaler board is damaged from the opto, i've seen it a few times and not managed to repair the board.
regards
Andy
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Hi Andy
I know its all confussing, but the PSU I am working on is the one that HASNT been turned on with U4 upside down.
Or when these boards fail is there a chance this damage will be caused anyway, judging by the fuse in this board it was a large short.
Is there anywhere else you can direct me too with my DMM to confirm this is Fubar'd
Cheers
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Hello,
WHen the boards blow its not that common to have a problem on the scaler however the opto being in the wrong way nearly always causes problems, the symptoms are dead, all the lights on the front on permanently or if you’re lucky the front buttons not working and the remote control being the only way to get the set on. Putting a working or repaired psu in wont sort the scaler and it would have to be replaced
Regards
Andy
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Hi Andy
Right I understand now, so what you are saying is I could go out buy a gleaming new psu and the problem will persist.
What I am finding hard to understand is that if I plug the PSU just using the AC plug (like you told me to do to check between c45 & C55) if I leave all other cables out of the board and check all the terminals on the board I am not getting any voltages at all just 5.10v from 5vs and 1.8v from STB.
Wouldnt there be a voltage at 12v or 3.3v or would all the other boards need to be plug in to stabilise all the other voltages.
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Depending on the design of boards, some psu’s are switched on by the main board, others will have all the voltages present (17pw boards are the best most common example).
You can switch most boards while on the bench by adding voltage or sometimes earthing. Not only does this mean a test can be done with out the rest of the set (although the set does not run with a load) it also tells you if the fault is on another board as is the case with this set.
If you look at the general forum on this site about the diagnostika tool, this is a palm sized device that works on this principle, simply because its how power supplies work.
We did some service info. a few weeks back showing how most engineers do this on a practical level.
Regards
Andy
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Hi Andy
Cheers for all you help on this one mate, my next question is do you have a scaler board in stock?
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Sorry no,
You can get the scaler from a scapper (it the little board on the right going to the screen and the psu) but if the psu has been repaired then it might of been damaged with the opto being incorrectly fitted.
regards
Andy
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Hi,
I have also been working on one of these boards for some time now and I am not sure if I also may have unintentionally put U4 in the wrong way round. I can't easily find a photo or description of which way round it should go.
Usually the boards are marked quite clearly (with a number "1") to show where pin1 of the opto (the one with the dimple next to it) should go. However all of the other optos on this board dont seem to follow that pattern and the printed "1" is on the opposite side to teh dimple! (none of these others have been out of the boardso they are as original)
Can anyone tell me the correct way round as I dont wish to change mine and find it was correct to begin with?
regards
John
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John,
INfo. on fitting the opto and checking the transformer is on the backer that comes with the kit, failing that, you can check but fitting the opto. the same way as the other 2. (the nearest being the other side of the stand by transformer or as always with opto's, follow the line that splits 2ndary/primary
regards
Andy