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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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JVC TV No red Color
Hi
I have JVC TV model AV-27D303.Green and Blue is Ok no Red color.I was checked Video amps transistors on CRT board.It looks good.Voltage on Rk goes 240V instead 160V as on Gk and Bk. Suspected IC 201 TOSHIBA 8812CSDNG3U68 which was replaced but problem still exist. Any suggestions? Thanks |
#2
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JVC TV No red Color
Compare the bias volts to the tube elements between all the colour
channels. If these are very close, then check that there is video drive at proper specs going from the outputs of the video amps to the CRT. If all this complies, then you have a bad CRT. Jerry Greenberg http://www.zoom-one.com -- "max" wrote in message ... Hi I have JVC TV model AV-27D303.Green and Blue is Ok no Red color.I was checked Video amps transistors on CRT board.It looks good.Voltage on Rk goes 240V instead 160V as on Gk and Bk. Suspected IC 201 TOSHIBA 8812CSDNG3U68 which was replaced but problem still exist. Any suggestions? Thanks |
#4
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JVC TV No red Color
I have seen two of these also. A 150 ohm resistor feeding signal from the
jungle IC to the base of the red output transistor, and a 270 ohm from the emitter to ground. If only one checks bad, replace the other also as it's likely to go soon after. -Woodie "Jason D." wrote in message ... On 3 Apr 2004 15:16:29 -0800, (Jerry Greenberg) wrote: Compare the bias volts to the tube elements between all the colour channels. If these are very close, then check that there is video drive at proper specs going from the outputs of the video amps to the CRT. If all this complies, then you have a bad CRT. Jerry Greenberg http://www.zoom-one.com Whoa! This fooled me, went far as changed a CRT on those JVC newer chassis even changed that super jungle! The problem was in the CRT board SMD resistors. Some had bad solder connection or one bad resistor. Check those! With meter and do a resoldering on those if you can't see anything look bad solder. The bias voltage will looks close but is still wrong. So far I seen about 4 of this after this initial incident, recent one was last week. :-O Summary: Check the CRT board for any bad part, duff resistor or bad solder joint (redo solder just the affected color). Cheers, Wizard |
#5
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JVC TV No red Color
thats what I suspected too I replaced one resistor for 15 Om some resistors
not installed by manufacture.Today I will check resistor between 270 Om and emitter.Thanks for suggestions guys. "Woodie Morris" wrote in message news I have seen two of these also. A 150 ohm resistor feeding signal from the jungle IC to the base of the red output transistor, and a 270 ohm from the emitter to ground. If only one checks bad, replace the other also as it's likely to go soon after. -Woodie "Jason D." wrote in message ... On 3 Apr 2004 15:16:29 -0800, (Jerry Greenberg) wrote: Compare the bias volts to the tube elements between all the colour channels. If these are very close, then check that there is video drive at proper specs going from the outputs of the video amps to the CRT. If all this complies, then you have a bad CRT. Jerry Greenberg http://www.zoom-one.com Whoa! This fooled me, went far as changed a CRT on those JVC newer chassis even changed that super jungle! The problem was in the CRT board SMD resistors. Some had bad solder connection or one bad resistor. Check those! With meter and do a resoldering on those if you can't see anything look bad solder. The bias voltage will looks close but is still wrong. So far I seen about 4 of this after this initial incident, recent one was last week. :-O Summary: Check the CRT board for any bad part, duff resistor or bad solder joint (redo solder just the affected color). Cheers, Wizard |
#6
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JVC TV No red Color
thats what I suspected too I replaced one resistor for 15 Om some resistors
not installed by manufacture.Today I will check resistor between 270 Om and emitter.Thanks for suggestions guys. "Woodie Morris" wrote in message news I have seen two of these also. A 150 ohm resistor feeding signal from the jungle IC to the base of the red output transistor, and a 270 ohm from the emitter to ground. If only one checks bad, replace the other also as it's likely to go soon after. -Woodie "Jason D." wrote in message ... On 3 Apr 2004 15:16:29 -0800, (Jerry Greenberg) wrote: Compare the bias volts to the tube elements between all the colour channels. If these are very close, then check that there is video drive at proper specs going from the outputs of the video amps to the CRT. If all this complies, then you have a bad CRT. Jerry Greenberg http://www.zoom-one.com Whoa! This fooled me, went far as changed a CRT on those JVC newer chassis even changed that super jungle! The problem was in the CRT board SMD resistors. Some had bad solder connection or one bad resistor. Check those! With meter and do a resoldering on those if you can't see anything look bad solder. The bias voltage will looks close but is still wrong. So far I seen about 4 of this after this initial incident, recent one was last week. :-O Summary: Check the CRT board for any bad part, duff resistor or bad solder joint (redo solder just the affected color). Cheers, Wizard |
#7
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JVC TV No red Color
Thanks guys for your help.Resistor between emitter and ground was bad.27 Om
on meter shows me 3.2kOm.Replace it back on 27Om return the red color back. "max" wrote in message ... thats what I suspected too I replaced one resistor for 15 Om some resistors not installed by manufacture.Today I will check resistor between 270 Om and emitter.Thanks for suggestions guys. "Woodie Morris" wrote in message news I have seen two of these also. A 150 ohm resistor feeding signal from the jungle IC to the base of the red output transistor, and a 270 ohm from the emitter to ground. If only one checks bad, replace the other also as it's likely to go soon after. -Woodie "Jason D." wrote in message ... On 3 Apr 2004 15:16:29 -0800, (Jerry Greenberg) wrote: Compare the bias volts to the tube elements between all the colour channels. If these are very close, then check that there is video drive at proper specs going from the outputs of the video amps to the CRT. If all this complies, then you have a bad CRT. Jerry Greenberg http://www.zoom-one.com Whoa! This fooled me, went far as changed a CRT on those JVC newer chassis even changed that super jungle! The problem was in the CRT board SMD resistors. Some had bad solder connection or one bad resistor. Check those! With meter and do a resoldering on those if you can't see anything look bad solder. The bias voltage will looks close but is still wrong. So far I seen about 4 of this after this initial incident, recent one was last week. :-O Summary: Check the CRT board for any bad part, duff resistor or bad solder joint (redo solder just the affected color). Cheers, Wizard |
#8
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JVC TV No red Color
Thanks guys for your help.Resistor between emitter and ground was bad.27 Om
on meter shows me 3.2kOm.Replace it back on 27Om return the red color back. "max" wrote in message ... thats what I suspected too I replaced one resistor for 15 Om some resistors not installed by manufacture.Today I will check resistor between 270 Om and emitter.Thanks for suggestions guys. "Woodie Morris" wrote in message news I have seen two of these also. A 150 ohm resistor feeding signal from the jungle IC to the base of the red output transistor, and a 270 ohm from the emitter to ground. If only one checks bad, replace the other also as it's likely to go soon after. -Woodie "Jason D." wrote in message ... On 3 Apr 2004 15:16:29 -0800, (Jerry Greenberg) wrote: Compare the bias volts to the tube elements between all the colour channels. If these are very close, then check that there is video drive at proper specs going from the outputs of the video amps to the CRT. If all this complies, then you have a bad CRT. Jerry Greenberg http://www.zoom-one.com Whoa! This fooled me, went far as changed a CRT on those JVC newer chassis even changed that super jungle! The problem was in the CRT board SMD resistors. Some had bad solder connection or one bad resistor. Check those! With meter and do a resoldering on those if you can't see anything look bad solder. The bias voltage will looks close but is still wrong. So far I seen about 4 of this after this initial incident, recent one was last week. :-O Summary: Check the CRT board for any bad part, duff resistor or bad solder joint (redo solder just the affected color). Cheers, Wizard |
#9
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JVC TV No red Color
On Sun, 4 Apr 2004 20:18:50 -0700, "max" wrote:
Thanks guys for your help.Resistor between emitter and ground was bad.27 Om on meter shows me 3.2kOm.Replace it back on 27Om return the red color back. Max, You're welcome! Jerry gave good advices but I sometimes have hard time reading what he's implying at. Cheers, Wizard |
#10
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JVC TV No red Color
On Sun, 4 Apr 2004 20:18:50 -0700, "max" wrote:
Thanks guys for your help.Resistor between emitter and ground was bad.27 Om on meter shows me 3.2kOm.Replace it back on 27Om return the red color back. Max, You're welcome! Jerry gave good advices but I sometimes have hard time reading what he's implying at. Cheers, Wizard |
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