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Stu jaxon <stankowalski02@gmail.com>: Dec 02 04:33PM -0800 Hi Group, I have an RCA led32c45rq not turning on, no pic, no sound. light on, 5v on stby power supply.. what board do i test next???

"ohg...@gmail.com" <ohger1s@gmail.com>: Dec 03 04:44AM -0800 On Wednesday, December 2, 2020 at 7:33:43 PM UTC-5, Stu jaxon wrote: > Hi Group, I have an RCA led32c45rq not turning on, no pic, no sound. light on, 5v on stby power supply.. what board do i test next???   Model number means nothing on these "RCAs". Post the board numbers.

Stu jaxon <stankowalski02@gmail.com>: Dec 03 06:02AM -0800 > On Wednesday, December 2, 2020 at 7:33:43 PM UTC-5, Stu jaxon wrote: > > Hi Group, I have an RCA led32c45rq not turning on, no pic, no sound. light on, 5v on stby power supply.. what board do i test next??? > Model number means nothing on these "RCAs". Post the board numbers.     rca fre01m3393lna35-a2 main board.. power supply re46hq0602-20141105

"ohg...@gmail.com" <ohger1s@gmail.com>: Dec 03 07:17AM -0800 On Thursday, December 3, 2020 at 9:02:39 AM UTC-5, Stu jaxon wrote: > > > Hi Group, I have an RCA led32c45rq not turning on, no pic, no sound. light on, 5v on stby power supply.. what board do i test next??? > > Model number means nothing on these "RCAs". Post the board numbers. > rca fre01m3393lna35-a2 main board.. power supply re46hq0602-20141105     Most of that series has a corrupt UL2 eeprom. I have the .bin file if you have a programmer.

Jezebels_couz <jbc3@three.net>: Dec 02 12:44PM -0500 On 12/2/20 2:47 AM, Johann Klammer wrote: >> In the process of finishing a 0-12 VDC @ 0-10 A switching power supply. Fairly new at this and wanted to ask about the shunt resistor. It will be in the ground line. Plans mentioned two options: either a custom shunt made from constantan wire or similar, or simply two 5W 0.1 ohm power resistors in parallel. Since I wanted to keep costs down, I am going with the power resistors, but I have a concern: I will be running 12 gauge wire for the output lines, but when the ground wire reaches the shunt, even the two resistors in parallel combined are far less than 12 gauge. Should I be concerned, or is the tiny resistor/ 12 gauge wire distance (basically just for the 12 ga wire to resistor wire connection) irrelevant to heating and losses? > If it's not too long, the heat might dissipate through the adjoining traces. > (if they didn't lie about the resistor wattage, that is)   Here's a diagram of what I was trying to explain. I wasn't sure I was very clear, so hopefully the diagram will better relate:   https://i.imgur.com/pYSRxiX.jpg

Jezebels_couz <jbc3@three.net>: Dec 02 12:45PM -0500 On 12/2/20 8:10 AM, Bob Engelhardt wrote:   > 12ga wire is 1.6R per 1000 feet*.  If your connection is 6", its > resistance is .0008R - <2% of your shunt & negligible.   > * - https://www.engineeringtoolbox.com/copper-wire-d_1429.html   Here's a diagram of what I was trying to explain. I wasn't sure I was very clear, so hopefully the diagram will better relate:   https://i.imgur.com/pYSRxiX.jpg

Jezebels_couz <jbc3@three.net>: Dec 02 12:45PM -0500 On 12/2/20 9:50 AM, Ralph Mowery wrote: >> irrelevant to heating and losses?   > The small wire of the resistors should handle it just fine. The main > reason for # 12 wire on the circuit is for the voltage drop.   Here's a diagram of what I was trying to explain. I wasn't sure I was very clear, so hopefully the diagram will better relate:   https://i.imgur.com/pYSRxiX.jpg

Ralph Mowery <rmowery28146@earthlink.net>: Dec 02 02:47PM -0500 In article <rq8jsg$ne0$3@dont-email.me>, jbc3@three.net says...   > Here's a diagram of what I was trying to explain. I wasn't sure I was > very clear, so hopefully the diagram will better relate:   > https://i.imgur.com/pYSRxiX.jpg   I understand what you are going to do.   To put your mind at ease Astron that makes power supplies has a 20 amp one that has two pass transistors. That means that each one would be good for 10 amps. They use only one .1 ohm 10 watt per transistor.   I have larger ones that do the same thing and they have worked for years with no problems.   Each of your resistors will need to be less than 3 watts at a 10 amp current if a quick calculation is correct.

Jezebels_couz <jbc3@three.net>: Dec 02 02:57PM -0500 On 12/2/20 2:47 PM, Ralph Mowery wrote: > with no problems.   > Each of your resistors will need to be less than 3 watts at a 10 amp > current if a quick calculation is correct.   Ok, just wanted to be sure as high current would still have to squeeze through those small areas and I wanted to minimize heating and loss. In my mind, it sort of defeated the purpose of using 12 gauge wire everywhere else to have a bottleneck at the end, but if all is well then no longer concerned. There will be two 5W resistors in parallel, so good to go on wattage. Thanks again.

Hilda Winkler <hildawinkler77@gmail.com>: Dec 02 09:35AM -0800 Hi Group, can someone help please? workin on a Vizio E480-B2 no pic, patient said, tv has sound no pic, i experienced neither. when testing psb, i got 5v stby, and 3.3 pwr_on 12v on 3 other pins,.. when test F1 301 no fuse on main board, i get 5v one side of fuse zero volts on other.. any suggestions on this matter will be taken seriously.

"ohg...@gmail.com" <ohger1s@gmail.com>: Dec 02 10:49AM -0800 > Hi Group, can someone help please? workin on a Vizio E480-B2 no pic, patient said, tv has sound no pic, i experienced neither. when testing psb, i got 5v stby, and 3.3 pwr_on 12v on 3 other pins,.. when test F1 301 no fuse on main board, i get 5v one side of fuse zero volts on other.. any suggestions on this matter will be taken seriously.   If you have an open fuse, 99% of the time a fuse isn't going to fix it, unless it's one of those square white ceramic fuses with the metal end caps (those will fail for no good reason). Since there's no schematic for the main board, you're going to need to trace out the circuit by hand. Unfortunately, you may find no direct short off the fuse, but a secondary short on the far side of a buck converter that the fuse feeds, which is harder to trace out. It might also ultimately lead to a shorted BGA chip. You can find a main board that model pretty cheap.   If you have a current limited supply, you can feed a current into the load side of the fuse (maybe 1 amp) and watch what gets hot. If a regulator IC gets hot, the short is probably on the output side of the regulator.

Michael Terrell <terrell.michael.a@gmail.com>: Dec 02 09:52AM -0800 On Tuesday, December 1, 2020 at 12:31:31 PM UTC-5, John Robertson wrote:   > for any period of time and it melts at lowish temps, it would probably > be of no use to the OP for his application. > John :-#)#   Hard waxes generally contain acids.

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