Mulja tv repair portal
Equipment Repairs => CRT TV forum => Topic started by: Restorer79 on March 14, 2012,09:11:31
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Hi All: Just wondering if anyone might know where I can get the Schematics or Service Manual for a Silvercrest CT2116 (UK) Television.
Thanks : Andy
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Hi,
Do you know what chassis it is?
Keith
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Hi Keith: Thank you for the reply, much appreciated. I've just been told that it's probably the Vestel 11AK30 chassis, so will try & locate a manual for this chassis & see what i can do from there.
Regards: Andy
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Vestel 11AK30
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Jordan: Thank you very much, that's excellent. Just an update to this: The set was Dead apart from the standby light being lit (Red) & a chirping noise from the PSU, anyway i've now opened it up & checked it over properly. I found that D805 (FR103) showed some strange readings both in and out of circuit so I replaced this with a listed equivalent a1N4007 (The 11AK30 Diagram shows a BY299 in this position) & continued to check the set. I found that there was a Dead short across the B+ line & traced this to Q602 the BU808DFI Line output transistor which was S/C from collector to emitter. I checked to make sure there were no other shorts then powered the set up with Q602 removed, as expected the set comes on in standby only but this time without the chirping noise.
Have ordered some BU808DFI's & will hopefully complete the repair when they arrive & put a smile back on the wife's face when she gets her bedroom TV back :13:
Anyway: Thanks for the help guys, much appreciated.
Regards: Andy
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Hi Andy,
You've prob sussed it but attach my 11AK30 file - Chris
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:c017: Chris, much obliged all info on this is handy. It's the other halfs set & she likes it. Noticed in your notes that it says about a special version of BU808DFI for this set, have you ever had problems fitting a standard replacement ?
Andy
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Ahhh the AK30! Nothing special about the BU808DFI, repaired 100's of these for hotels when I was working in Greece.
Replace the BU808, the main cause of the failure is C613 (line drive coupling), also worth changing C810, C848,C826, C623. Check for dry joints on the line drive transistor and associated components. Some models of the AK30 seemed to have a badly moulded rear case that pressed on the LOPTX pins, so check for dry joints on the LOPTX too and cut the pins a little shorter.
I got bored fixing these! But I was on commission, so when 10 arrived at once I knew cool beer would be waiting for me at the Jolly Roger.
Discharge the main smoothing block before working on it, they bite!
Keith
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Hi Keith: Thanks again for the reply, appreciate it. Yep smoothing cans can certainly bite the unwary, my Daughter saw me clipping a 100k across the can yesterday & wanted to know why. She's nearly finished her 1st year in College learning Industrial Electronics & Robotics, but when they've been taught about SMPS faults, nobody appears to have told them about Discharging the caps. I always clip a 100k across even if there is already a bleed resistor fitted, always change the line drive coupling caps when i've got a blown output transistor (Once bitten twice shy) & will change the others as well to be on the safe side. Your right about the LOPTx being dry jointed by the way it certainly was, also the chopper transformer was pretty bad.
Will check the other things you mention as well, when it's back up on the bench.
Gotta be fair working on this re-inforced why I hate working on modern equipment, everything is just so flimsy. Give me a dozen Vintage set repairs over 1 of these anyday.
Cheers: Andy