Re: Toshiba sdp7000 no sound
After reading that post, I figure you have decided the amp chips are fried. That would pretty much write it off in my mind so I decided to try something on my own. once we eliminated c118\115 from the circuit, that left ic100/101 and r127 being the possible paths to ground. I removed r127 raising the resistance to over 100K to ground. When I re-applied power still no sound, but now I got 4.99 volts at pin 4 of ic100/101.
It's 2AM here, I'm going to bed, and maybe think about it more tomorrow. I'm starting to think the amp...
efilnikufecin
Member
Last Activity: 12-17-2012, 07:55 PM
Joined: 11-08-2012
Location: Mattoon IL
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Re: Toshiba sdp7000 no sound
1900 ohms at pin 4 with the 2 caps removed.Leave a comment:
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Re: Toshiba sdp7000 no sound
I checked knowing they would be, and sure enough they are.Leave a comment:
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Re: Toshiba sdp7000 no sound
1854 ohmsLeave a comment:
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Re: Toshiba sdp7000 no sound
Using the line level output of a cd player, R channel connected to an input jack for ground left channel connected to the negative pin of c112 and it's equivalent c111 for the opposite channel gave no output.Leave a comment:
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Re: Toshiba sdp7000 no sound
pulled q100, didn't damage the traces, but it came off in 2 pieces. Still no sound, and voltage at pin 4 of IC100/101 is still at 1.82v I cannot seem to find R106,107, or 126 on the board. I was wanting to check the +5v input to see if it was weak.Leave a comment:
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Re: Toshiba sdp7000 no sound
Went to the link, same data sheet as I already had. Breaking out the soldering iron now to pull Q100.Leave a comment:
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Re: Toshiba sdp7000 no sound
After looking at the parts list Page 31 in the service manual it shows:
IC100 AF500060 0IMCRMZ002A "IC,MICRO CONTROLLER" MP7720 MONOLITHIC POWER SYST
IC101 AF500060 0IMCRMZ002A "IC,MICRO CONTROLLER" MP7720 MONOLITHIC POWER SYST
The schematic diagram shows mps7720 and with a magnifying glass the chip shows mps7720. So the parts list says I have the right data sheet, but the diagram and chip differ. This is where my confusion comes in as to whether or not I have the right one.Leave a comment:
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Re: Toshiba sdp7000 no sound
Q100 is a very tiny surface mount transistor. Would it be a major issue if I removed the whole thing? I don't think I can lift just the collector pin.Leave a comment:
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Re: Toshiba sdp7000 no sound
Pin 4 of IC 100 and 101 is at 1.82v both with mute on, and mute off.
In answer to the first question, I have checked, and I have had others go through the menus and check to see if they could find a setting that would disable sound.
Edit: btw that is not a stupid question, I have solved that very problem on a few RCA TVs with just a few button presses on a remote control.Last edited by efilnikufecin; 11-08-2012, 11:10 PM.Leave a comment:
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Toshiba sdp7000 no sound
I have a Toshiba SDP7000 TV/DVD combo that has no sound when used like one would normally use a television. When I hook it up to my high power stereo system via the headphone jack and turn the volume all the way up I can hear it through my stereo, but with a hum.
I downloaded a repair manual for this set, and began diagnosis:
1 Check input source: Pass
2 Check input/output IC1: I was unable to determine the input pin. The output pins gave the same hum when the volume was turned to a high level on my stereo.
3 Check input/output ic100,101: These are mps7720 audio...
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