Identify Transformers for Surround Sound System
Identify Transformers for Surround Sound System
(OP)
I have a Philips surround sound system that now needs new transformers as I attempted a capacitor fix that went south. The transformers have the following markings: R7249T 6HC (and the C is underlined)
These are 4 pin transformers on the AC inlet. Anyone know a manufacturer I should be looking at? If you google search that part number you'll just find my post on Fixya...
I don't have the input ratings handy but can post them later if it helps. Thanks for any help/advice. <tg>
These are 4 pin transformers on the AC inlet. Anyone know a manufacturer I should be looking at? If you google search that part number you'll just find my post on Fixya...
I don't have the input ratings handy but can post them later if it helps. Thanks for any help/advice. <tg>





RE: Identify Transformers for Surround Sound System
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If we learn from our mistakes I'm getting a great education!
RE: Identify Transformers for Surround Sound System
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RE: Identify Transformers for Surround Sound System
Bought on Craigslist for $100. Ran for a while just fine with a long warmup cycle and buzz when powering up. Once it came on the sound system worked great. Finally stopped getting beyond the buzz phase so I searched and found the do-it-yourself solution was to replace some undersized capacitors ($3 at RadioShack). Unfortunately I replaced the wrong ones. When I applied power I was immediately made aware of my error. Thought I'd spend another few bucks to fix it, else I'll be buying a new system.
RE: Identify Transformers for Surround Sound System
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RE: Identify Transformers for Surround Sound System
RE: Identify Transformers for Surround Sound System
The parts I know I fried are at the top left. Looking at the board I now see the ref des are L101 & L102 (indicating they may be some kind of inductors rather than transformers?).
In any event, for $26 I'm just replacing the board to avoid having to chase other issues. Thanks again for the help.
RE: Identify Transformers for Surround Sound System
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If we learn from our mistakes I'm getting a great education!
RE: Identify Transformers for Surround Sound System
Remove the parts, measure the diameter of the wire to get the wire gauge, cut the wires off the bobbin with a xacto knife and count the 'loops' to get the turns-count, then start re-winding.
Now, I'm assuming that since they are marked as "L" that they are single inductors, but they might use "L" as a designation for common mode chokes or differential mode chokes, in which case you will have two windings as if they were transformers. The picture does show two sections on the bobbin, so they may be chokes. In that case you will have to determine the direction of each winding when you rewind to get the filtering right, and determine which pin went to which coil since there will be a coil on each power input line for a total of two coils and four connecting pins.
RE: Identify Transformers for Surround Sound System
Thanks all,
<tg>