Toshibia 40rv525u Blinking Power light

[tom66]

Re: Toshibia 40rv525u Blinking Power light

Well I see lots of bad Rubycon caps from my experience also.
Even MAC computers failed due to bad Rybycon caps.

I've seen bad Rubycons too, just like I have seen bad Panasonic, bad Nichicon and bad Chemicon. The failures have only occurred (in my experience) on motherboards, which are brutal places for capacitors to operate, especially with the high ripple current and high temperatures. In general, in a power supply, they are excellent caps, with very good reliability.

[budm]

Re: Toshibia 40rv525u Blinking Power light

I will never rule out any brand of caps, if it is made by human, it can fail.
At this point he needs to put dummy load on the 5V line to see if it can even handle 1/2A load.

[tom66]

Re: Toshibia 40rv525u Blinking Power light

I will never rule out any brand of caps, if it is made by human, it can fail.
At this point he needs to put dummy load on the 5V line to see if it can even handle 1/2A load.

Most caps are machine made now. But I would generally look elsewhere before suggesting cap failure with good caps. The dummy load is a good idea. Three (1.5V) torch bulbs in series provides approx 300mA load for reference.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

I tested the power board with a long string of leds. The power supply turned on and supplied good stable 5v, 12v and 24v without voltage dropping.

Could the problem be a 8-pin soic power mosfet right near the connector on the video board?

[budm]

Re: Toshibia 40rv525u Blinking Power light

LED's will only draw about 0.02A (or 20mA), very very low current.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Would a 10ohm 2 watt resistor suffice? Don't have any bulbs that work
On that little of a voltage.

[budm]

Re: Toshibia 40rv525u Blinking Power light

Yes, try 10 Ohms first (this will draw 0.5A, power will be 2.5Watt), just long enough to see if 5V will stay at 5V.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

Hooked up a 4.75v .5A flashlight bulb between pwr and 5v. Board is supplying steady 5v,12v, and 24 output from all connectors.

[budm]

Re: Toshibia 40rv525u Blinking Power light

It looks like your 5v is OK, but how did you get the 12V/24V reading without having the main board hook up to get the PS_ON signal from the main board to turn on the 12/24V power supply section.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

not sure, thought it used the pwr pin?

[budm]

Re: Toshibia 40rv525u Blinking Power light

So If you hook every thing back together, will the 5V go low again? If it does, then the main board must be drawing too much current than the 5V power supply can handle, that is the only reason I can think of.

[knoxrebel]

Re: Toshibia 40rv525u Blinking Power light

How can we determine where the short is on the video board?

[tom66]

Re: Toshibia 40rv525u Blinking Power light

http://www.youtube.com/watch?v=_1pxf4faLAY
and/or
http://www.youtube.com/watch?v=XhqwC3BFBug