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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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#1
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JVC TV repair help
I am trying to fix my JVC AV27BP4 TV. The TV has no HV, the HOT
appears good but it has no startup drive. The startup drive is driven by another transistor which appears good, and that just hooks to a big JVC IC through a single resistor, the VC2024Z. I'm not really sure where to go from here... I can't find any service info on the tv, or a datasheet for the VC2024Z(yeah right!). Is it likely that this IC could be bad? Or should I start checking all the discretes around it... Any tips would be greatly appreciated! |
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#2
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JVC TV repair help
Is standby B+ getting to the micro? When power is turned on does the
jungle chip provide startup H-pulses to the H driver circuitry that feeds the HOT? Is the power supply coming on and regulating properly to provide B+ to the flyback? These and lots of other things you can check without a schematic -- Best Regards, Daniel Sofie Electronics Supply & Repair --------------------------------- "James Peverill" wrote in message ... I am trying to fix my JVC AV27BP4 TV. The TV has no HV, the HOT appears good but it has no startup drive. The startup drive is driven by another transistor which appears good, and that just hooks to a big JVC IC through a single resistor, the VC2024Z. I'm not really sure where to go from here... I can't find any service info on the tv, or a datasheet for the VC2024Z(yeah right!). Is it likely that this IC could be bad? Or should I start checking all the discretes around it... Any tips would be greatly appreciated! |
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#3
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JVC TV repair help
Is standby B+ getting to the micro? When power is turned on does the
jungle chip provide startup H-pulses to the H driver circuitry that feeds the HOT? Is the power supply coming on and regulating properly to provide B+ to the flyback? These and lots of other things you can check without a schematic -- Best Regards, Daniel Sofie Electronics Supply & Repair --------------------------------- "James Peverill" wrote in message ... I am trying to fix my JVC AV27BP4 TV. The TV has no HV, the HOT appears good but it has no startup drive. The startup drive is driven by another transistor which appears good, and that just hooks to a big JVC IC through a single resistor, the VC2024Z. I'm not really sure where to go from here... I can't find any service info on the tv, or a datasheet for the VC2024Z(yeah right!). Is it likely that this IC could be bad? Or should I start checking all the discretes around it... Any tips would be greatly appreciated! |
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#4
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JVC TV repair help
The b+ supply seems good, as do the other voltages (power supply seems good). The JVC chip doesn't seem to be outputing anything. I noticed something interesting... I turned the set on with the high voltage leads to the yoke board disconnected (figured no high voltage doesn't matter)... and oddly enough the high voltage seemed to fire up for a half-second or so. Whould this indicate anything? Any ideas? Thanks for your help! james Sofie wrote: Is standby B+ getting to the micro? When power is turned on does the jungle chip provide startup H-pulses to the H driver circuitry that feeds the HOT? Is the power supply coming on and regulating properly to provide B+ to the flyback? These and lots of other things you can check without a schematic -- Best Regards, Daniel Sofie Electronics Supply & Repair --------------------------------- "James Peverill" wrote in message ... I am trying to fix my JVC AV27BP4 TV. The TV has no HV, the HOT appears good but it has no startup drive. The startup drive is driven by another transistor which appears good, and that just hooks to a big JVC IC through a single resistor, the VC2024Z. I'm not really sure where to go from here... I can't find any service info on the tv, or a datasheet for the VC2024Z(yeah right!). Is it likely that this IC could be bad? Or should I start checking all the discretes around it... Any tips would be greatly appreciated! |
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#5
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JVC TV repair help
The b+ supply seems good, as do the other voltages (power supply seems good). The JVC chip doesn't seem to be outputing anything. I noticed something interesting... I turned the set on with the high voltage leads to the yoke board disconnected (figured no high voltage doesn't matter)... and oddly enough the high voltage seemed to fire up for a half-second or so. Whould this indicate anything? Any ideas? Thanks for your help! james Sofie wrote: Is standby B+ getting to the micro? When power is turned on does the jungle chip provide startup H-pulses to the H driver circuitry that feeds the HOT? Is the power supply coming on and regulating properly to provide B+ to the flyback? These and lots of other things you can check without a schematic -- Best Regards, Daniel Sofie Electronics Supply & Repair --------------------------------- "James Peverill" wrote in message ... I am trying to fix my JVC AV27BP4 TV. The TV has no HV, the HOT appears good but it has no startup drive. The startup drive is driven by another transistor which appears good, and that just hooks to a big JVC IC through a single resistor, the VC2024Z. I'm not really sure where to go from here... I can't find any service info on the tv, or a datasheet for the VC2024Z(yeah right!). Is it likely that this IC could be bad? Or should I start checking all the discretes around it... Any tips would be greatly appreciated! |
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