I have powersuplly BN44-00438B It works but The big cap 450v has only 165v
when on. please help.
http://www.amazon.com/Samsung-BN44-0.../dp/B008DIUKOC
when on. please help.
http://www.amazon.com/Samsung-BN44-0.../dp/B008DIUKOC
-
-
Re: power supply board BN44-00438B repair
I suspect the PFC circuit isn't working. I would check the FETs and diodes around the big cap, as well as the PFC driver IC underneath. -
Re: power supply board BN44-00438B repair
Thanks Glitcher.
I see IC gmo465r (faichild) I do not what is this ic.Can not find datasheet.Comment
-
Re: power supply board BN44-00438B repair
How sure are you about that part #?Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Re: power supply board BN44-00438B repair
I am not sure. I see a small ic Fan7930B may be this ic is used for FPC.
Without main cable to power board It has 13v but big cap has only 165v instead
380v.
May be gmo465r is for 13v and 5v run voltageLast edited by hienton2; 04-13-2014, 05:57 PM.Comment
-
Re: power supply board BN44-00438B repair
That is PFC controller; have you checked Vcc voltage?Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Re: power supply board BN44-00438B repair
Yes I have 15v at pin8 of ic pfc.
pin 1 of this ic has 1v.Last edited by hienton2; 04-13-2014, 06:38 PM.Comment
-
Re: power supply board BN44-00438B repair
Is PFC diode (usually on heatsink) not shorted? Are current sense resistor(s) (<1 ohm usually) both OK?Last edited by tom66; 04-13-2014, 06:37 PM.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Re: power supply board BN44-00438B repair
I see white 5W resistor connect to fet of PFC .It is ok,. I check all diodes . They are OK. I do not see diode for PFC ckt on heat sink.Comment
-
Re: power supply board BN44-00438B repair
Hello,
I am working the same power supply. I noticed my standby voltage is only 4V, that sounds not close enough to 5V to me. Also on the scope it appears to be oscillating. I replaced the Fan7930B, it is a PWM with integrated switching fet, same 4V on the standby output. Is the big electrolytic supposed to be at 380V? Mine os only 155 to 160V.Comment
-
Re: power supply board BN44-00438B repair
can i just ask what the mains voltage is in your country?Comment
-
Re: power supply board BN44-00438B repair
That is fine then but it should rise once the TV turns on. Rise to about 390V.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Re: power supply board BN44-00438B repair
The TV wont turn on. I only have a strange 5V standby, nothing else.
Need to go and look at the output of the PFC converter and see if it is a mess or not. Any idea what the output voltage of the PFC is?
Thanks!Comment
-
Re: power supply board BN44-00438B repair
390V or so with a tolerance of about ±15V.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Re: power supply board BN44-00438B repair
Thanks for that, so it appears in my case the PFC converter is not running.
There is no VCC at the VCC pin of the PFN controller PWM. So now i am digging through the traces to see what powers the chip. Just from a cursory look at looks like it runs through a few optos before it gets to the PWM.
Another question on the subject, I ordered the service manual for this set because i could not find it online. $15 later, i get a file with troubleshooting tips the tend to end in statements like 'Replace Main Board" LOL Is it standard these days for service manuals not to include the schematic?
I have not ever seen one that did not.Comment
-
Re: power supply board BN44-00438B repair
Hey guys,
Sorry about all the nube questions.
After re-reading the comments above, I have a few more questions.
Someone said that the PFC voltage would rise once the TV is turned on.
So i guess my understanding of the sequence of events is all wrong.
It appears that the PFC is kind of Or'ed with the main diode bridge. And the converter that generates the 5V and 13V are driven by that Or'ed voltage.
So if the PFC is not always running, can the 5V/13V converter generate enough start up power to get the set on before the PFC kicks in?
What I wouldn't give for a schematic! LOLComment
-
Re: power supply board BN44-00438B repair
Yes, the 5V/13V will usually run without the PFC under light load (i.e. standby only.) This will provide enough Vcc (from an auxillary winding) to the PFC IC to run.
The PFC power is mostly used for main output for driving the bulbs/LEDs. There will also usually be an "undervoltage lockout" which prevents the main output from starting if the PFC is N.G.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Re: power supply board BN44-00438B repair
OK great info thanks!
Also, since my 5VA is only 4V, is that enough V for the logic to run on the main board? (it stays 4V with or without that main board connected)Comment
-
Re: power supply board BN44-00438B repair
Hmm, is the 4V steady or unstable? 4V is probably not enough.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
-
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow
This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board
After all of... -
Hi everyone,
I am trying to fix a samsung washinmachine power supply main board.
I already replaced it with another one to fix the machine but i want to try understand the issue with the old board.
Therefore i hope to be able to get some help to explain what to check in order to troubleshoot.
The power supply board reference is the following: DC41-00189a
I have followed one thread (https://www.badcaps.net/forum/troubl...ingmachine-rel... -
I was working on this CNC machine today found no keyboard functioning no control relay powering on
The screen powered on and was giving an operation error but the manual was not very clear about what the error exactly was but with a little bit of troubleshooting and finding out that the control relays not powering on and no keyboard functions we narrowed down to this one switching power supply which of course does not have any indicator LED light they are on the keyboard interface/relay controller board
Found shorted diodes on main controller relays there are 3 of them that... -
I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time...
Comment