Need help with resistor value please

[budm]

Re: Need help with resistor value please

Or just read this thread.
https://www.badcaps.net/forum/showthread.php?t=78439

[Diah]

Re: Need help with resistor value please

[QUOTE=budm;980613] answer OP why you want Ohm test when Diode Test was OK to him,

OP: could you please show us yours DM which you do test with... thanks.

[budm]

Re: Need help with resistor value please

Oh look, I edit post in this thread here too! After I found more info about the unit.
https://www.badcaps.net/forum/showpo...18&postcount=6

[budm]

Re: Need help with resistor value please

[QUOTE=Diah;980619]

answer OP why you want Ohm test when Diode Test was OK to him,

OP: could you please show us yours DM which you do test with... thanks.

To Diah if you want to know, read below:
if you would like to have lesson for electronic mathematics to analysis and print good design... ask with respectful i will show you and teach you... other wise keep swim with yours fool of unknown how we calculated the Freq before the print...

[budm]

Re: Need help with resistor value please

Please see attached pictures of IC9801 and IC9201.

IC9801 PFC IC UCC28063: Check resistance between VCC pin 12 and GND pin 6.

IC9201 SMPS IC SSC9522: Check the resistance between VCC pin 2 and GND pin 4.

[JunkmanJimbo]

Re: Need help with resistor value please

IC9801 PFC IC UCC28063: Check resistance between VCC pin 12 and GND pin 6. With my ohm meter set to 20k I get a reading of 2.72 between pin 12 and pin 6.

IC9201 SMPS IC SSC9522: Check the resistance between VCC pin 2 and GND pin 4.

With my ohm meter set to 20k I get a reading of 2.72 between pin 2 and pin 4.

[budm]

Re: Need help with resistor value please

So both IC's show exact same reading, 2.72K?

[JunkmanJimbo]

Re: Need help with resistor value please

So both IC's show exact same reading, 2.72K?

That is correct. Both show the same reading.

[budm]

Re: Need help with resistor value please

That is correct. Both show the same reading.

OK, let me look at the board layout.

[budm]

Re: Need help with resistor value please

Check the resistance between the two legs of cap C9211, C9146.

[JunkmanJimbo]

Re: Need help with resistor value please

Check the resistance between the two legs of cap C9211, C9146.

They both actually show the same numbers 2.72.

[budm]

Re: Need help with resistor value please

They both actually show the same numbers 2.72.

OK.
Lift up one end of the jumper wire J928 or J930 of the board, this will disconnect the switched VCC from the 12V/24V SMPS IC.

Put in the new R9114 SMD resistor.
You will power up the power board by itself first to make sure the R9114 will not blow up, then you will connected a 220 ~ 470 Ohms (what ever value you have in that range) resistor between PS-ON and 5V/3.3V pin to force on the power supply and see if you do have 380 ~ 400VDC on the main 450VDC main filter cap or if R9114 will blow up again.
BTW, do you know what wattage of the replacement of R9114 is? Is it the same physical size as original one?
This power supply and mainboard also known for bad solder joints on the connector that goes to the main board.

[JunkmanJimbo]

Re: Need help with resistor value please

OK.
Lift up one end of the jumper wire J928 or J930 of the board, this will disconnect the switched VCC from the 12V/24V SMPS IC.

Put in the new R9114 SMD resistor.
You will power up the power board by itself first to make sure the R9114 will not blow up, then you will connected a 220 ~ 470 Ohms (what ever value you have in that range) resistor between PS-ON and 5V/3.3V pin to force on the power supply and see if you do have 380 ~ 400VDC on the main 450VDC main filter cap or if R9114 will blow up again.
BTW, do you know what wattage of the replacement of R9114 is? Is it the same physical size as original one?
This power supply and mainboard also known for bad solder joints on the connector that goes to the main board.

I can do part of this but I don't have any resistors to perform that task between PS-ON and 5V/3.3V pin. Is there any other way to do this? The SMD R9114 resistor is the resistor I got from the youtube video posted earlier. Sorry, I don't have everything I need to do this. If there is another way please let me know. I appreciate your patience, understanding and all of your help.

[budm]

Re: Need help with resistor value please

I can do part of this but I don't have any resistors to perform that task between PS-ON and 5V/3.3V pin. Is there any other way to do this? The SMD R9114 resistor is the resistor I got from the youtube video posted earlier. Sorry, I don't have everything I need to do this. If there is another way please let me know. I appreciate your patience, understanding and all of your help.

You can do the force on test without the resistor, I suggest to use resistor in case you make wrong connection that can cause damage to the circuit, so if you perform the connection correctly for sure then you can do without using resistor, so inspect real well on how you have the PS-ON and 5V/3.3 pins connected together, I would solder one wire to each pin then you can connect the end of the wires together after powering up then wait about 5 seconds before connecting the two ends of the wire together to simulate power on condition.

[JunkmanJimbo]

Re: Need help with resistor value please

You can do the force on test without the resistor, I suggest to use resistor in case you make wrong connection that can cause damage to the circuit, so if you perform the connection correctly for sure then you can do without using resistor, so inspect real well on how you have the PS-ON and 5V/3.3 pins connected together, I would solder one wire to each pin then you can connect the end of the wires together after powering up then wait about 5 seconds before connecting the two ends of the wire together to simulate power on condition.

Thank you budm. I will try to get this done tomorrow and I will definitely let you know the outcome. Thanks again for everything. It is very much appreciated.

[budm]

Re: Need help with resistor value please

Right now we are trying to find out which circuit is drawing so much current to flow through R9114 that cause it to burn up.
If it works, you should see about 380 ~ 400VDC on the main filter cap when you touch the PS-On wire and the 5V/3.3V together.
There will be no 12V/24V since we lift up one end of the jumper wire that feed switched VCC to the 12V/24V SMPS IC.

[JunkmanJimbo]

Re: Need help with resistor value please

Right now we are trying to find out which circuit is drawing so much current to flow through R9114 that cause it to burn up.
If it works, you should see about 380 ~ 400VDC on the main filter cap when you touch the PS-On wire and the 5V/3.3V together.
There will be no 12V/24V since we lift up one end of the jumper wire that feed switched VCC to the 12V/24V SMPS IC.

Please explain main filter cap and if possible the location. Thanks

[budm]

Re: Need help with resistor value please

Please explain main filter cap and if possible the location. Thanks

There are 3 of them, they are 82uF 450VDC C9804, C9805, C9823.
You can check the Voltage on the two legs of any one of the 3 caps since they are connected in parallel.
You must be real careful since you are working on the HOT deadly side so not touch anything with your hands or body, do not let the test probes slip either.

[Topcat]

Re: Need help with resistor value please

[QUOTE=Diah;980619]

answer OP why you want Ohm test when Diode Test was OK to him,

OP: could you please show us yours DM which you do test with... thanks.

You need to cool your act down a little....

[JunkmanJimbo]

Re: Need help with resistor value please

There are 3 of them, they are 82uF 450VDC C9804, C9805, C9823.
You can check the Voltage on the two legs of any one of the 3 caps since they are connected in parallel.
You must be real careful since you are working on the HOT deadly side so not touch anything with your hands or body, do not let the test probes slip either.

Hey budm, sorry I didn't get a chance to do this yesterday. I just now followed your procedure and the resistor blew as soon as I plugged in the power cord. I didn't even get the chance to power on the board. The first time it didn't blow until I turned the TV on. This makes no sense. I did use a small clamp with rubber ends to clamp the board to the table to hold it in place. I clamped it over the power connector where the power cord plugs in. I don't know why that would have made a difference.