Need help with resistor value please

[budm]

Re: Need help with resistor value please

Well, Standby power supply needs troubleshooting to find out what went out this time, that means I have to spend more time looking at the pictures of the board to come up with test points for you to test and I am really busy helping other people here as well (I have been staying up til 1 ~ 2 AM my time help troubleshooting and I am very tire) so you just have to wait or some one, I.E. RJ, DICK_BARTON, etc. may jump in and help you out.

[JunkmanJimbo]

Re: Need help with resistor value please

Well, Standby power supply needs troubleshooting to find out what went out this time, that means I have to spend more time looking at the pictures of the board to come up with test points for you to test and I am really busy helping other people here as well (I have been staying up til 1 ~ 2 AM my time help troubleshooting and I am very tire) so you just have to wait or some one, I.E. RJ, DICK_BARTON, etc. may jump in and help you out.

I understand completely. Just when you get time. Get some rest most of all. Thanks for everything and I'll wait for you. Thanks again.

[R_J]

Re: Need help with resistor value please

In your first post you indicated that R9101 was open, If this resistor (Q9101 source resistor) was indeed open, it is likely 99% that IC9101 is blown. When R9101 goes open, as soon as Q9101 is turned on, over 300vdc is applied to ic9101's CS pin via R9104 (330Ω)

[JunkmanJimbo]

Re: Need help with resistor value please

Hey guys, hope you've had a great weekend!
I found a replacement power supply for this TV and now I seem to have a new problem. When I installed the power supply for the first time the TV came on and went into a boot loop. After rebooting several times the TV came on on the 8th boot. When it comes on it works fine, even if I disconnect the power and reconnect it. I also tried disconnecting the power, holding down the power button for 1 minute and it still boots right up without any issues. It appears that when the TV is left unplugged for several days or a week or so, the TV starts by going into the boot loop and starts working again on the 8th boot. Any ideas? Thanks in advance.

[JunkmanJimbo]

Re: Need help with resistor value please

In your first post you indicated that R9101 was open, If this resistor (Q9101 source resistor) was indeed open, it is likely 99% that IC9101 is blown. When R9101 goes open, as soon as Q9101 is turned on, over 300vdc is applied to ic9101's CS pin via R9104 (330Ω)

R_J, sorry for the long delay. Since I got the replacement power supply I checked the resistor on that board and it checked the same on both boards. Please read my post from late yesterday to see if you can help. Thanks in advance.

[JunkmanJimbo]

Re: Need help with resistor value please

Hey guys, hope you've had a great weekend!
I found a replacement power supply for this TV and now I seem to have a new problem. When I installed the power supply for the first time the TV came on and went into a boot loop. After rebooting several times the TV came on on the 8th boot. When it comes on it works fine, even if I disconnect the power and reconnect it. I also tried disconnecting the power, holding down the power button for 1 minute and it still boots right up without any issues. It appears that when the TV is left unplugged for several days or a week or so, the TV starts by going into the boot loop and starts working again on the 8th boot. Any ideas? Thanks in advance.

I checked the TV again this morning and apparently if the TV sits overnight unplugged it does it. This time it booted on the 9th boot. Please help if you can. Thanks in advance.

[JunkmanJimbo]

Re: Need help with resistor value please

I checked the TV again this morning and apparently if the TV sits overnight unplugged it does it. This time it booted on the 9th boot. Please help if you can. Thanks in advance.

Something to add......I turned off the TV but left it plugged in and left it that way for a few hours. When I turned the TV back on it started the boot loop again. So it doesn't seem to matter if it's plugged in or unplugged. I need to determine the problem as soon as possible because the power supply board is still under warranty, so if that's the problem I can exchange it or get a refund. Please help. Thanks!

[budm]

Re: Need help with resistor value please

Si when it is in the boot loop, did you check the standby Voltage to see if it is steady?
It sounds like the main board problem if you can unplug the power for a long time then it works OK again.

[JunkmanJimbo]

Re: Need help with resistor value please

Si when it is in the boot loop, did you check the standby Voltage to see if it is steady?
It sounds like the main board problem if you can unplug the power for a long time then it works OK again.

Thanks Budm. Please read my post #84, #86 and #87. There are a few different scenarios here. It seems to do it whether the tv is plugged in or not. Once I get it to boot, I can turn it off, and then immediately turn it back on and it turns back on normally. I haven't checked any voltages yet.

[JunkmanJimbo]

Re: Need help with resistor value please

Thanks Budm. Please read my post #84, #86 and #87. There are a few different scenarios here. It seems to do it whether the tv is plugged in or not. Once I get it to boot, I can turn it off, and then immediately turn it back on and it turns back on normally. I haven't checked any voltages yet.

And, once it's on it will play for hours without any problems. Does this sound like a power supply issue or a main board issue? My warranty period is running out on this power supply board. Please help.

[budm]

Re: Need help with resistor value please

The key point is to find out if the main board is sending all the control signals to the power supply board or not when the TV is not working.

[JunkmanJimbo]

Re: Need help with resistor value please

The key point is to find out if the main board is sending all the control signals to the power supply board or not when the TV is not working.

I just checked the voltages at standby and on/off pins. Standby stays stable at 5.18 volts when the tv is off and when the tv is in boot loop. On/off while in boot loop shows 3.18 volts but changes just before the Vizio logo comes up and the voltage is varying between .08 to .14 volts but after the logo comes up it goes back to 3.18 volts. Is this the voltages you wanted me to check? Thanks.

[budm]

Re: Need help with resistor value please

I just checked the voltages at standby and on/off pins. Standby stays stable at 5.18 volts when the tv is off and when the tv is in boot loop. On/off while in boot loop shows 3.18 volts but changes just before the Vizio logo comes up and the voltage is varying between .08 to .14 volts but after the logo comes up it goes back to 3.18 volts. Is this the voltages you wanted me to check? Thanks.

So the Standby power supply is steady at 5.18V but the ON/OFF (Backlights ON/OFF) control is not steady.
How about the PS-ON (Power supply ON/OFF)? Is it steady?

[JunkmanJimbo]

Re: Need help with resistor value please

So the Standby power supply is steady at 5.18V but the ON/OFF (Backlights ON/OFF) control is not steady.
How about the PS-ON (Power supply ON/OFF)? Is it steady?

PS-ON is 3.71 volts but drops to .06 volts just before the Vizio logo comes up and then it goes back to 3.71 volts.

[budm]

Re: Need help with resistor value please

PS-ON is 3.71 volts but drops to .06 volts just before the Vizio logo comes up and then it goes back to 3.71 volts.

The main board is getting steady Standby Voltage to run but the main board is not steady and sending out fluctuating control Voltages when it is not working right..

You may have EEPROM problem on the main board or bad BGA connections.

You may want to read these threads:
https://www.badcaps.net/forum/search...rchid=19191296

https://www.badcaps.net/forum/showth...t=Vizio+M65-C1

[JunkmanJimbo]

Re: Need help with resistor value please

The main board is getting steady Standby Voltage to run but the main board is not steady and sending out fluctuating control Voltages when it is not working right..

You may have EEPROM problem on the main board or bad BGA connections.

You may want to read these threads:
https://www.badcaps.net/forum/search...rchid=19191296

https://www.badcaps.net/forum/showth...t=Vizio+M65-C1

Thanks budm! I ordered a pre-programmed EEPROM last night. I will update when I get it installed.

[JunkmanJimbo]

Re: Need help with resistor value please

I received and installed the pre-programmed EEPROM today and it's still doing the same thing....boot loop. So, you believe there are bad BGA connections. So, that means the problem is definitely in the main board and not the power supply, correct? So, I guess the next step is to replace the main board, correct? Or, is there a way to fix the BGA connections without reballing? Thanks again, budm, for all your help. It is very much appreciated.

[Diah]

Re: Need help with resistor value please

MAN MAN MAN... my post

Dear....

i don't wish any conflict with any member over here .. especially budm who spend allot of his over time here.. but if some one missed looking on parts will miss whole set. and here we are.. no one talked or wrote on the Freq signal.. no one used tool to track the logic signal.. where we could start now ... ?? just buy and test ?? this never being repair..

[JunkmanJimbo]

Re: Need help with resistor value please

I sent the main board to be repaired on Ebay but it came back doing the same exact thing. He said he tested it before he sent it back and it was working fine but when I got it the boot loop still remains. My question is.....can the power supply or any other board on the tv cause a boot loop issue or is the main board the only board that can cause this? I am arguing back and forth with the guy that said he repaired it trying to get my money back....$89.86 but I wanted to be sure the issue would most likely be with the main board. Sorry for the long post and I appreciate any help you can offer.

[budm]

Re: Need help with resistor value please

I sent the main board to be repaired on Ebay but it came back doing the same exact thing. He said he tested it before he sent it back and it was working fine but when I got it the boot loop still remains. My question is.....can the power supply or any other board on the tv cause a boot loop issue or is the main board the only board that can cause this? I am arguing back and forth with the guy that said he repaired it trying to get my money back....$89.86 but I wanted to be sure the issue would most likely be with the main board. Sorry for the long post and I appreciate any help you can offer.

So what exactly did he repair, what part did he replace?
Does he actually install the board top verify that it actually work?