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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 AV32730
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JVC AV32730
On Wed, 24 Mar 2004 22:04:52 -0500, "john"
wrote: Change the 1000mfd next to big diode to left of reg heatsink. kip Ding. Now I remember, This model didn't ring a bell but I know the location: C926, usually 1000uF 35V but sometimes I see 25V. Very, very common in that type of chassis. Use hi-freq 105C caps. The ones JVC used was 85C and way SMPS was designed (STRF-6626) put huge stress on 13V diode, cooking the cap next to it. BTW, that diode isn't that big, more like medium like between small and large. Also change small capacitor that filtering power for the horizontal driver transformer. It's between two hot resistors. While at it, resolder LA7832 vertical IC. Get the JVC fixed well, it is nice TV. Cheers, Wizard -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message |
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JVC AV32730
C926 if the regulator IC is running, otherwise you had better get the manual
and be very thorough on the primary of the PS and feedback circuits. Leonard "john" wrote in message .. . Change the 1000mfd next to big diode to left of reg heatsink. kip -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message .. . Set is dead, no relay click or anything. Have 168 vdc from the rectifier to the switcher transformer, Dont have a schematic, Could not find standby volts . Can anyone give me some check points to look at( Where to look for the standby volts) Thanks Charlie |
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JVC AV32730
Also I don't know if it applies to this particular model, but some JVCs have 2
diodes in series off the horiz output collector to ground. If one of these shorts it draws down the 130v supply and shuts off all power. For some reason the horiz output does not short, like other sets that use this design when the diode shorts. |
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JVC AV32730
Change the 1000mfd next to big diode
to left of reg heatsink. kip -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message .. . Set is dead, no relay click or anything. Have 168 vdc from the rectifier to the switcher transformer, Dont have a schematic, Could not find standby volts . Can anyone give me some check points to look at( Where to look for the standby volts) Thanks Charlie |
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JVC AV32730
Checked all the caps, replaced a couple that were high esr but still no
help, I think at this point I need the schematic Charlie "john" wrote in message .. . Did you ESR all the filter caps in PS ? kip -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message news  The reg IC STRS5708 is not running. I have 168VDC on the input and nothing else.. Also there is no large switching transistor in the area of the P/S, Is the switcher contained in the reg IC? Anyone have a schematic of the P/S on this model? I sure would appreciate a copy. Sams does not list this model Thanks Charlie "Leonard Caillouet" wrote in message news:nj78c.1025$pM1.804@lakeread06... C926 if the regulator IC is running, otherwise you had better get the manual and be very thorough on the primary of the PS and feedback circuits. Leonard "john" wrote in message .. . Change the 1000mfd next to big diode to left of reg heatsink. kip -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message .. . Set is dead, no relay click or anything. Have 168 vdc from the rectifier to the switcher transformer, Dont have a schematic, Could not find standby volts . Can anyone give me some check points to look at( Where to look for the standby volts) Thanks Charlie |
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JVC AV32730
On Thu, 25 Mar 2004 21:41:41 -0600, "Charlie East"
wrote: Checked all the caps, replaced a couple that were high esr but still no help, I think at this point I need the schematic Charlie Did you keep meter on voltage outputs of this SMPS and watched it while plugging in? This kind of SMPS using switching STR stuff voltages tend to spike then fade away if there's a problem ahead of outputs. STR IC needs two items, good feedback and supply voltage to start up and stay running within regulation. Check the resistors, optisolator and caps are good. I assume this chassis uses same SMPS for standby and run power. Cheers, Wizard |
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#9
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JVC AV32730
Did you ESR all the filter caps in PS ?
kip -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message news The reg IC STRS5708 is not running. I have 168VDC on the input and nothing else.. Also there is no large switching transistor in the area of the P/S, Is the switcher contained in the reg IC? Anyone have a schematic of the P/S on this model? I sure would appreciate a copy. Sams does not list this model Thanks Charlie "Leonard Caillouet" wrote in message news:nj78c.1025$pM1.804@lakeread06... C926 if the regulator IC is running, otherwise you had better get the manual and be very thorough on the primary of the PS and feedback circuits. Leonard "john" wrote in message .. . Change the 1000mfd next to big diode to left of reg heatsink. kip -- "Watch the return E-Mail addy its false" "Charlie East" wrote in message .. . Set is dead, no relay click or anything. Have 168 vdc from the rectifier to the switcher transformer, Dont have a schematic, Could not find standby volts . Can anyone give me some check points to look at( Where to look for the standby volts) Thanks Charlie |
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