 Posted: Sat Jun 29, 2013 9:09 am Post subject: |
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| Some time gone since that discussion, but still was very helpful to fix a broken Sony KLV S40A10. The diode d6903 had a short too. | |
| Posted: Fri Jun 11, 2010 10:14 am Post subject: |
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| ba159 will do the job, avail from chs | |
| Posted: Sun Dec 28, 2008 6:39 pm Post subject: |
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Persistence can be a good thing  Good job .... btw, I think that was one of the few Japanese built units! |
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| Posted: Sun Dec 28, 2008 9:06 am Post subject: |
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Thanks everyone for the help. Ive replaced the diode with the suggested one and the tv's been running happly for the last 7 hours. after 5 or so hours, turned it off to check the diode. It was still only warm so that was a really good sign. Hoping if someone has the same issue that they find this post on google, it might help  |
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| Posted: Sat Dec 27, 2008 1:33 pm Post subject: |
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| Hi Ray, thanks again for your valuable feedback. Hope to carry some good news tomorrow when I pick up and solder the part on. Going to go with uf-4004 as suggested. The other parts you recommend isnt easily avaliable in Nz (as far as I can tell) and so i'll try and locate the original if ordering international, will give confidence in long term use but for now I just want to get it going first to ensure thats the only issue |
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| Posted: Sat Dec 27, 2008 5:42 am Post subject: |
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| Matt, Well done in finding the diode! ; Keep in mind, when dealing with switching power supplies, all scan diodes are almost always fast switching, in this case, while the breakdown voltage & amperage between 1N4004 & 10ERB20 are similar, the recovery time is waay off, sorta like driving a sports car or...a horse and a buggy The inability of keeping up with pulses will quickly translate in to heat & eventual failure of the device. So, as you have mentioned, anything around 1A, 200v,60ns or faster recovery time (trr) usually is an acceptable substitute. update; in further looking at the specs, you'd probably be safer with a bit more headroom with UF4004 JVC calls for the following substitutes from different manufacturers on 10ERB20: AU01Z, ERA18-02, 1SR153-400, 1F4G Ray |
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| Posted: Sat Dec 27, 2008 3:39 am Post subject: |
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| This is turning more into a blog Anwyay, I'm thinking of replacing the diode with a generic UF4003 Untra Fast (50ns compared to 60ns) 200v 1A diode. Thinking if this one doesnt heat up then it'll be fixed. Does anyone think this diode is not right? Only thing I can come up with is speed = heat issues just cos none of the other protection circuits has kicked off and I saw the tv working happly for a few mins before the 1n4004 diode fell off.... ps: I'm living in New Zealand so hard to pick up original parts but will get original ordered if needed.... |
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| Posted: Sat Dec 27, 2008 12:55 am Post subject: |
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| also, to add to the top.... checked the diode that dropped off and its still good..... ummm... wonder what that mean??? | |
| Posted: Sat Dec 27, 2008 12:52 am Post subject: |
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| Update - requerst for help K, after poking around and checking all the fuses, ps etc, I attached the diodes in the power supply board. I found d6903 to be bad (shorted). Its a "10ERB20-TB3" DIODE. I have hunted for replacements but noithing locally avaliable. Instead, I have looked up the 1n4004 which is a common bridge reflector diode and the specs seemed close enough (though I dont really think I know enough to make that call). I removed the bad diode and soldered on the new one just onto the bottom side of the board (so legs were not completely in the slot as the legs on the 1n4004 is fatter then the original). put everything back together and wam, it worked..... However..... after 30 secs I could smell a burning smell. I couldnt see anything actually burning and no smoke etc. Left it on thinking lets see what happens, if the item starts to burn, atleast I can identify it... anyway, after 2 or so mins, pop, tv turned off and the diode had unsoldered itself (most likely from heat, it was originally quite secure). The good thing is that Ive seen the tv working so I dont think i'm that far away, even had time to plug in the tv arial and see a chanel work.... however, more questions  So is the 1n4004 a good enough sub for the original 10ERB20-TB3 diode? The cap smoothing the power after the diode is rated 50V so didnt think voltage would be an issue... spec wise i thought they look close enough.... maybe switching speed? also, if it is a good enough sub for the original, what would be causing the heat? too much current drain? I would have thought too much current would blow a fuse somewhere (theres so many all over the place).... so close... |
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| Posted: Fri Dec 26, 2008 12:07 am Post subject: |
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| Thanks heaps for the help and looking into teh schematics Vetch. I found the schematic to beabit crazzy, would have been nice if sony schematics were along the lines of datasheets which explain what is actually happening. Would have been even nicer (for me) if the power section was just basic regulators etc I'll keep poking around abit longer and see if anything pops out at me. In the worst case, I'll have the actual screen (fingers crossed its in good shape) incase someone else ends up smashing something through their screen and wants to sell it for cheap Again, thanks to all for who helped |
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