It's not the cables. Lol. The audio and LED meter for the right channel from both decks shows no signal. Can someone please tell me what to check first? I went ahead an reflowed the solder on most of the IC's. No change. Thanks!!!!
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Both right channels dead on dual deck JVC KD-W110 cassette player
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Both right channels dead on dual deck JVC KD-W110 cassette player
Last edited by JimBanville; 02-28-2021, 12:46 PM.Tags: None
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Is there a schematic/service manual for it? Can you cross-record, that is from R ch on one deck to the other? Just to see if there is internal R ch activity, compared to Line Out.
No R ch in both decks likely means the REC-PLAY switch circuitry or further downstream is the problem. If it's only one channel in one deck, easier to track down.
I would go to the tape head preamps IC801, IC802 and confirm there is signal output there.
Wild guess is after those tape-head pre-amp IC's is the electronic switching CD4066B's IC803, IC804 which I would suspect.
Write down DCV measured at their 14-pins. It's easy to see the R and L circuits, take comparison readings between channels, to see if a mux shorted in the IC.
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Originally posted by redwire View PostIs there a schematic/service manual for it? Can you cross-record, that is from R ch on one deck to the other? Just to see if there is internal R ch activity, compared to Line Out.
No R ch in both decks likely means the REC-PLAY switch circuitry or further downstream is the problem. If it's only one channel in one deck, easier to track down.
I would go to the tape head preamps IC801, IC802 and confirm there is signal output there.
Wild guess is after those tape-head pre-amp IC's is the electronic switching CD4066B's IC803, IC804 which I would suspect.
Write down DCV measured at their 14-pins. It's easy to see the R and L circuits, take comparison readings between channels, to see if a mux shorted in the IC.
Sorry but I don't have the schematic. Do I need to have a tape playing to test those IC's? Thanks!
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Originally posted by redwire View PostIs there a schematic/service manual for it? Can you cross-record, that is from R ch on one deck to the other? Just to see if there is internal R ch activity, compared to Line Out.
No R ch in both decks likely means the REC-PLAY switch circuitry or further downstream is the problem. If it's only one channel in one deck, easier to track down.
I would go to the tape head preamps IC801, IC802 and confirm there is signal output there.
Wild guess is after those tape-head pre-amp IC's is the electronic switching CD4066B's IC803, IC804 which I would suspect.
Write down DCV measured at their 14-pins. It's easy to see the R and L circuits, take comparison readings between channels, to see if a mux shorted in the IC.
I don't know how I could cross-record from one transport to the other. I suppose I could de-solder the L/R record head wires and reverse them on one transport?
I just connected a source to the L/R inputs and pressed record without a tape inserted. Both LED meters moved and I got audio from both L/R outputs, if that means anything.
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Originally posted by redwire View PostIs there a schematic/service manual for it? Can you cross-record, that is from R ch on one deck to the other? Just to see if there is internal R ch activity, compared to Line Out.
No R ch in both decks likely means the REC-PLAY switch circuitry or further downstream is the problem. If it's only one channel in one deck, easier to track down.
I would go to the tape head preamps IC801, IC802 and confirm there is signal output there.
Wild guess is after those tape-head pre-amp IC's is the electronic switching CD4066B's IC803, IC804 which I would suspect.
Write down DCV measured at their 14-pins. It's easy to see the R and L circuits, take comparison readings between channels, to see if a mux shorted in the IC.
1.3 & 1.3
.8 & .7
5.3 & 5.5
13.6 & 14.3
0 & 0
4.5 & 5.4
.7 & .7
1.3 & 1.3
Comment
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Originally posted by redwire View PostIs there a schematic/service manual for it? Can you cross-record, that is from R ch on one deck to the other? Just to see if there is internal R ch activity, compared to Line Out.
No R ch in both decks likely means the REC-PLAY switch circuitry or further downstream is the problem. If it's only one channel in one deck, easier to track down.
I would go to the tape head preamps IC801, IC802 and confirm there is signal output there.
Wild guess is after those tape-head pre-amp IC's is the electronic switching CD4066B's IC803, IC804 which I would suspect.
Write down DCV measured at their 14-pins. It's easy to see the R and L circuits, take comparison readings between channels, to see if a mux shorted in the IC.
9.7/9.7/9.7/9.7/.4/.4/0
13.2/12.7/12.7/9.7/9.7/9.7/9.7
9.7/9.7/9.7/9.7/12.7/12.7/0
13.2/.4/.4/9.7/9.7/9.7/9.7
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Originally posted by JimBanville View PostHere are the results of IC 804 and 803...
9.7/9.7/9.7/9.7/.4/.4/0
13.2/12.7/12.7/9.7/9.7/9.7/9.7
9.7/9.7/9.7/9.7/12.7/12.7/0
13.2/.4/.4/9.7/9.7/9.7/9.7
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Re: Both right channels dead on dual deck JVC KD-W110 cassette player
Still a little confusing on the pin numbers, I take it to be:
Code:CD4066 IC804 IC803 Pin 1 9.7 9.7 Pin 2 9.7 9.7 Pin 3 9.7 9.7 Pin 4 9.7 9.7 Pin 5 0.4 12.7 Pin 6 0.4 12.7 Pin 7 GND 0 0 Pin 8 9.7 9.7 Pin 9 9.7 9.7 Pin 10 9.7 9.7 Pin 11 9.7 9.7 Pin 12 12.7 0.4 Pin 13 12.7 0.4 Pin 14 +VDD 13.2 13.2
The DC voltages look OK. If you have a scope or signal tracer, going through the audio path will be the fastest way to troubleshoot. What do you have?
You can try Record as well, see if the R ch makes it to tape.
What is the part # on the head preamps IC801, IC802? Although the voltages look pretty matched between channels.Last edited by redwire; 03-02-2021, 03:27 PM.
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