![]() |
|
|
Thread Tools | Display Modes |
![]() |
#1 |
New Member
Join Date: Dec 2014
City & State: Sydney, NSW
My Country: Australia
I'm a: Knowledge Seeker
Posts: 3
|
![]() Hi There
I have a short circuit in my BN44-00264A PSU. The FS801S blows immediately when powered up. There are no smells or visibly obvious suspect components. I've been reading through related forum posts and I think I have narrowed down the problem. I removed components QI820 and QI821 based on a forum thread I was following (but I think this may have been unnecessary in my case). I tried the lamp across the fuse terminals. In my case I have electrician test lamps and these glowed brightly. A few days later I discovered ~zero resistance across the +/- terminals of BD801S while it was still in circuit. I removed BD801S and still measured the same resistance across BD801S. Yesterday, I noticed ~zero resistance across the Gate and Drain and the Drain and Source of QP801S. I removed this component and I'm now measuring an open circuit. Does QP801S sound like the faulty component. Should I replace all the components I have removed or just the QP801S. Also, I'm in Australia. What is a good place to source components? I have found rs.online.com which have the QI820 & QI821 components. They have a STF11NM60ND. What does the D on the end mean? Is this the same component as STF11NM60N. http://au.rs-online.com/web/p/mosfet...stors/7612745/ They don't have the Bridge Rectifier TS6B05G, they have a KBU605G http://au.rs-online.com/web/p/bridge...fiers/6875894/ Has anyone tried alibaba.com or aliexpress.com for components? Thanks Mark |
![]() |
![]() |
![]() |
#2 |
Badcaps Veteran
Join Date: Feb 2011
City & State: Perdido Beach, Alabama
My Country: USA
Line Voltage: 120v AC 60Hz
I'm a: Knowledge Seeker
Posts: 267
|
![]() Comparing the datasheets looks like KBU605G will work in place of TS6B05G.
If your fairly sure you did not overheat the components removed, and they test good you can reuse them. Extra letters on P/N's are usually for inventory control or designate if on tape or loose. I have had some luck sourcing IC's on ebay. |
![]() |
![]() |
![]() |
#3 |
Badcaps Veteran
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,206
|
![]() "A few days later I discovered ~zero resistance across the +/- terminals of BD801S while it was still in circuit. I removed BD801S and still measured the same resistance across BD801S" Where is this BD801S? I cannot find in in the diagram.
"Yesterday, I noticed ~zero resistance across the Gate and Drain and the Drain and Source of QP801S. I removed this component and I'm now measuring an open circuit. Does QP801S sound like the faulty component." That means the PFC IC UP801S and the resistor/diode network connected to the Gate of the MOSFET may be damaged also. I would not replaced the PFC MOSFET QP801S, 802S without replacing the IC at the same time or you will take a big chance blowing the new MOSFETs. BTW, TOM66 website has the diagram for your board
__________________
Never stop learning Basic LCD TV and Monitor troubleshooting guides. http://www.badcaps.net/forum/showthr...956#post305956 Voltage Regulator (LDO) testing: http://www.badcaps.net/forum/showthr...999#post300999 Inverter testing using old CFL: http://www.badcaps.net/forum/showthr...er+testing+cfl Tear down pictures : Hit the ">" Show Albums and stories" on the left side http://s807.photobucket.com/user/budm/library/ TV Factory reset codes listing: http://www.badcaps.net/forum/showthread.php?t=24809 Last edited by budm; 01-27-2015 at 12:33 AM.. |
![]() |
![]() |
![]() |
#4 |
Slow Learner
Join Date: Dec 2010
City & State: Lancashire UK
Posts: 7,853
|
![]() In this SJ picture it is top right corner near the 2 red/orange film caps
http://www.shopjimmy.com/media/catal...264a-top_7.jpg The OP really needs to post pictures of his own boards
__________________
Please upload pictures using attachment function when ask for help on the repair http://www.badcaps.net/forum/showthread.php?t=39740 |
![]() |
![]() |
![]() |
#5 | |
Badcaps Veteran
Join Date: Oct 2011
City & State: QLD
My Country: Australia
Line Voltage: 240VAC
I'm a: Forum Junkie
Posts: 6,369
|
![]() Quote:
KBU605G is KBU 7.1 mm thick, pin spacings are 2mm narrower between the legs you can get a visual idea here http://www.taiwansemi.com/upload/fil...ine/BRIDGE.pdf looks like an oddball , found RS1005M which also seems hard to find locally. UTSOURCE takes 3 weeks though from china, some on ebay but expensive way to go. The prices are USD so with the $ sinking keep that in mind. Also watch out for those on backorder parts at RS, sometimes they are automated and keep refreshing. They had some parts i was after and they were endlessly on backorder and never came in even after 12 months, suspect they became obsolete or discontinued Last edited by tw2005; 01-27-2015 at 07:03 AM.. |
|
![]() |
![]() |
![]() |
#6 |
Badcaps Veteran
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,206
|
![]() Here is the diagram.
|
![]() |
![]() |
![]() |
#7 | |
Badcaps Veteran
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,206
|
![]() Quote:
|
|
![]() |
![]() |
![]() |
#8 |
New Member
Join Date: Dec 2014
City & State: Sydney, NSW
My Country: Australia
I'm a: Knowledge Seeker
Posts: 3
|
![]() Hi There
Thanks for all the replies and sorry for not posting photos of my board or the schematic diagram. I've taken on board everyone's advice and comments. I've place an order with Utsource.net for the MOSFETs, Rectifier and the PFC chip as well as the diodes feeding into QP801S, QP802S. I'll update when I receive the parts and solder them in. |
![]() |
![]() |
![]() |
#9 |
New Member
Join Date: Jan 2015
City & State: London
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 1
|
![]() LG TV 42px5d-eb power not switching on
|
![]() |
![]() |
![]() |
#10 |
New Member
Join Date: Sep 2017
City & State: Catalunya
My Country: España
I'm a: Knowledge Seeker
Posts: 5
|
![]() |
![]() |
![]() |
![]() |
#11 |
New Member
Join Date: Mar 2021
City & State: Karlsruhe
My Country: Germany
I'm a: Knowledge Seeker
Posts: 3
|
![]() Too bad @Langfo never posted the solution
![]() I have pretty much the same problem, FS801S blown and zero resistance across +- (or -+) on BD801S while still in circuit, which for my take only leaves four components that might be short - the rectifier BD801S itself, one of the capacitors CP801S and CP802S or the transformer/transducer LP801S (least likely for my take). On my board the QP801S and QP802S have ~300Ohms measured with a digital multimeter on GS or GD (or SG or DG for that matter), and 0 Ohms for DS or SD - to me that sounds fine, right? So my next step will be to take the board into work on Monday, more professional tools there, and take out BD801S, and the capacitors CP801S and CP802S to measure them out of circuit. I hope that just one of them blew and nothing else... - Philip |
![]() |
![]() |
![]() |
#12 |
Badcaps Veteran
Join Date: Jun 2012
City & State: ☻
My Country: Canada
I'm a: Professional Tech
Posts: 8,155
|
![]() If you can unsolder pin 6 of LP801s then you can isolate the bridge rectifier from the mosfet circuit.
|
![]() |
![]() |
![]() |
#13 |
Badcaps Veteran
Join Date: Aug 2015
City & State: Cardiff
My Country: Wales
Line Voltage: 230V AC, 50Hz
I'm a: Hobbyist Tech
Posts: 6,544
|
![]() I would suspect either one or both mosfets are shorted so I would take them out to check.
__________________
Willing to help but I'm no expert. |
![]() |
![]() |
![]() |
#14 | |
New Member
Join Date: Mar 2021
City & State: Karlsruhe
My Country: Germany
I'm a: Knowledge Seeker
Posts: 3
|
![]() Quote:
It was all a bit a b*tch to desolder because there are rivets in some of the PCB holes. So I have to replace the mosfets and will also replace the UP801S (FAN7530), since that quite often seems to be the cause for the mosfets to blow. Now, what's a good source of components in europe? Mouser and Digikey both have the components but charge €20 for shipping to Germany. Nikko Electronics sells from the UK on ebay... anybody know if that's a trustworthy source? - Philip |
|
![]() |
![]() |
![]() |
#15 | |
Badcaps Veteran
Join Date: Jan 2015
City & State: worcester
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 3,276
|
![]() Quote:
|
|
![]() |
![]() |
![]() |
#16 |
Badcaps Veteran
Join Date: Aug 2015
City & State: Cardiff
My Country: Wales
Line Voltage: 230V AC, 50Hz
I'm a: Hobbyist Tech
Posts: 6,544
|
![]() I would imagine there are plenty of ebay suppliers since most commercial companies do have a minimum purchase cost before postage is free.
You could look at cpc.co.uk or Farnell and see if they have what you want and their delivery charges. |
![]() |
![]() |
![]() |
#17 |
ivtec
Join Date: Dec 2008
City & State: Fall River, Mas,
My Country: USA
Line Voltage: 120-60hz
I'm a: Hobbyist Tech
Posts: 1,689
|
![]() |
![]() |
![]() |
![]() |
#18 |
New Member
Join Date: Mar 2021
City & State: Karlsruhe
My Country: Germany
I'm a: Knowledge Seeker
Posts: 3
|
![]() OK, so I got the FAN7530 and the STF11NM60N off ebay from nikkoelec, an UK-based vendor to avoid the shipping times from China on the one hand and the shipping cost of vendors like mouser or digikey on the other hand.
They shipped TO-220 housing (with metal tab) instead of TO-220FP (isolated) ![]() A good thing I could get hold of two heat condcutive TO-220 pads and fitting plastic screws to mount them. Now the TV's been running for 90mins without problems, smells or smoke. ![]() Thanks everybody for the help, - Philip |
![]() |
![]() |
![]() |
#19 |
New Member
Join Date: May 2022
City & State: Solingen
My Country: Deutschland
I'm a: Knowledge Seeker
Posts: 1
|
![]() Hallo Philip,
Wars das mit der Reparatur und läuft der TV noch immer ? Stehe derzeit vor dem gleichen Problem. 6.3AT Sicherung ist durch und an den Mosfets und dem Gleichrichter messe ich einen Schluss... Gruß Thomas |
![]() |
![]() |
![]() |
Thread Tools | |
Display Modes | |
|
|