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#1 |
Member
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
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![]() Hi
I'm trying to repair an internal power supply in a Hitachi DV-PF4E video/dvd combi player. I've narrowed the fault down to Q1001 a N channel mosfet (2SK3566) which seems to be shorted, when powering the power suppy this takes out resistor R1043. I don't have any of these mosfets but do have some FDPF5N50UT's would this be a suitable replacement? I've attached the schematic for the DV-PF4E the power supply section being on page 88, I've also attached the datasheets for the mosfets. |
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#2 |
Member
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
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![]() I've replaced the mosfet Q1001 with the same part as was installed originally, but resistor R1043 keeps failing going open circuit.
Does anyone know what other component could be causing this? |
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#3 |
Badcaps Veteran
Join Date: Jan 2016
City & State: Sochi
My Country: Russia
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![]() Rather, Q1001 struck again, since you did not check the entire strapping of it, if Q1001 pierces, then it carries off the strapping, check these components.
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#4 |
Member
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
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![]() I found that the transistor Q1003 was shorted between base and emitter so I replaced that and changed Q1001 again, but I'm getting a loud buzzing I think from T0011 the power transformer and still getting no output.
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#5 |
Member
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
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![]() I do now seem to have output, the only voltage that seems low is the AL-30 all the others seem fine.
The buzzing is worse when the power supply is connected to the main board. This text is from the service manual When buzz sound can be heard in the vicinity of power circuit. Check if there is short circuit on the rectifying diode and the circuit in each rectifying circuit of secondary side and service it if defective. (D013, D014, D016, D018, D019, D1008, D1016, D1030, IC1002, IC1003, Q051, Q053, Q055, Q056, Q058, Q1052, Q1053, Q1055) Check if there is short circuit on the rectifying diode Does this mean the rectifying diode's on the primary side? |
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