Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting Power Supplies and Power Supply Design
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 10-10-2021, 05:17 AM   #1
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
Default DV-PF4E(UK) Power suppy repair

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.
Attached Files
File Type: pdf hitachi_dv-pf4e.pdf (7.95 MB, 7 views)
File Type: pdf 2SK3566_datasheet_en_20131101.pdf (216.0 KB, 4 views)
File Type: pdf FDPF5N50UT-D.pdf (686.9 KB, 3 views)
pintglass is offline   Reply With Quote
Old 10-15-2021, 01:35 AM   #2
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
Default Re: DV-PF4E(UK) Power suppy repair

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?
pintglass is offline   Reply With Quote
Old 10-15-2021, 12:45 PM   #3
lotas
Badcaps Veteran
 
Join Date: Jan 2016
City & State: Sochi
My Country: Russia
I'm a: Knowledge Seeker
Posts: 1,703
Default Re: DV-PF4E(UK) Power suppy repair

Quote:
Originally Posted by pintglass View Post
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?
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.
Attached Images
File Type: png DV-PF4E.PNG (55.5 KB, 11 views)
lotas is offline   Reply With Quote
Old 10-16-2021, 10:03 AM   #4
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
Default Re: DV-PF4E(UK) Power suppy repair

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.
pintglass is offline   Reply With Quote
Old 10-17-2021, 07:25 AM   #5
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 79
Default Re: DV-PF4E(UK) Power suppy repair

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?
pintglass is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums © 2003 - 2023
Powered by vBulletin ®
Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 01:54 AM.
Did you find this forum helpful?