Toshibia 40rv525u Green Blinking light and questions about Caps!!

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

OK I it is Pulsing at the same speed as the Lcd, Highest Pulse was 2.73v but it is just on for a brief second. Thanks!

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Can you also check the ACD pin?

Can you get hold of a 2.2k resistor? (1/4W, Carbon Film, 5% - should be available at Radio Shack.)

The clues point to a main board problem right now, as the Pwr voltage should be stable to turn the supply on.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Acd is about 2v and the pulse is Synced with the Pwr pin using both multimeters.

Does it have to be a 1/4w? Or that exact Value? I have a "ton" literally of old boards that I might be able to find this on.

Also, just two other questions,

Does the polarity Matter on film caps? And what does happen if you don't put a low esr cap in?

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

I addition to the post above, Is there a way to test just the power board? Like Jump It? Or would that be a bad idea if there is a short or something turning it off?

[retiredcaps]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Like Jump It?

I never had too, but you could hookup fresh 2 AA batteries in series to get 3V DC and connect that to the PWR pin? If the voltages come up stable (5V, 12V, 24V, etc) on the power board then you know the problem lies somewhere on the main/logic board.

Something like this

http://www.ebay.ca/itm/320562976160

or you can just make it at home with electrical tape and wire?

3V DC or higher is usually the threshold for PSON or similar type pin (PWR) from the main to the power board.

PS. I don't know the ramifications of doing this, so caveat emptor. Some power supplies may not operate properly without a load?

PPS. I have jumped a few ATX power supplies (short green to black), but they were given to me for free and I was trying to repair and troubleshoot them. So if anything went wrong, there was no real loss (I always wore safety glasses, you never know with free stuff).

[retiredcaps]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

If the voltages come up stable (5V, 12V, 24V, etc) on the power board then you know the problem lies somewhere on the main/logic board.

Actually, I could be wrong about the above statement. The power board alone without load could display the proper voltages, but fail under load (i.e. when main board is connected).

I have one lcd monitor where the power board has stable and correct voltages, but would drop everytime the logic board was connected. I haven't solved it yet. A slip of the probe shorted out some diodes on the power board and I haven't replaced them yet.

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Acd is about 2v and the pulse is Synced with the Pwr pin using both multimeters.

Okay, that might be okay. The pulse might just be interference from the rest of the supply.

Does it have to be a 1/4w? Or that exact Value? I have a "ton" literally of old boards that I might be able to find this on.

No, any value would probably do, just ideally with long leads so you can plug it into the right pins.

Also, just two other questions,

Does the polarity Matter on film caps?

Not as far as I'm aware. Electrolytics, tantalums, niobium and a few other types of capacitors are polarised, but others are nonpolar.

And what does happen if you don't put a low esr cap in?

The supply works intermittently or not at all. Or it works for a month or two, then dies. Or, the caps go really bad and kill something on the main board. (Samsung LCD TVs are notorious for corrupting the EEPROM when capacitors go bad inside them. The EEPROM stores settings so the TV gets very confused and it needs resetting.)

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Ok It's been a day or two since I worked on this anyway, I removed both boards and had a stable 5v line, No pulsing.

Should I do the jump will that even prove anything? If I do where do I connect the negative terminal of the battery?

What should I do from here?

Also, I am going to look for that resistor. Thanks!

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

^^^In addition to this post, I found a 2700k is this OK? I can look again, I literally have tons of boards to pull stuff from.

I think it is a quarter watt how do you tell that? Just the Size?

Whats the plan? I can solder a pair of jumpers on to get to the pins.

Thanks!

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

^^^In addition to this post, I found a 2700k is this OK? I can look again, I literally have tons of boards to pull stuff from.

I think it is a quarter watt how do you tell that? Just the Size?

Whats the plan? I can solder a pair of jumpers on to get to the pins.

Thanks!

You ideally need close to 2.2k - 4.7k. 2700k is 2.7 meg ohms so 1000x out of spec.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

LoL or I'm just really out of spec on typing I meant 2.7k how do you tell if its a 1/4w?

Its red violet red that is 2.7k right?

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

LoL or I'm just really out of spec on typing I meant 2.7k how do you tell if its a 1/4w?

Any old resistor would do... most likely one with leads will be at least 1/8w which is more than enough...

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Now I'm second guessing my self, red violet red that is 2.7k right?

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Now I'm second guessing my self, red violet red that is 2.7k right?

What do I do now? I soldered a couple jumpers on it.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Where should I connect the resistor? Should I try to jump the power board? If so where do I connect the Negative terminal of the 9v Battery? To Ground?

[PlainBill]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

Tom66 is rather busy with exams at this time. I would connect one end of the resistor to the standby output of the power supply (5VSB?) and the other to the PS_ON input. Then when you apply AC power, the entire power supply should start.

PlainBill

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

OK, no problem. OK I think those two pins are +5v and PWR, is that correct? DO you know what the ACD is for? Also what Boards should I leave connected if any?

Thanks!

Good luck with the exams tom66!!

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

OK, no problem. OK I think those two pins are +5v and PWR, is that correct? DO you know what the ACD is for? Also what Boards should I leave connected if any?

Thanks!

Good luck with the exams tom66!!

ACD tells the TV the power cable is still plugged in. (AC Detect.) If the power cable is unplugged (or the supply drops out), the TV gets about 50 milliseconds to save all settings to memory and perform a controlled shut down.

I expect connecting it between 5V and PWR will be sufficient. You could even solder it in place, to make it easier to test it, and remove it later.

For the initial test, disconnect all boards as it's only the output voltages we are concerned about. Then the other boards can be connected and further tests can be performed.

[ComputerGeek]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

OK, Hooked it up, and nothing all voltages were the same as before nothing except the +5v line well I didn't actually measure all of them but the main lines for the inv and main boards had nothing.

I actually have a little trick so you don't have to solder doesn't work if you have the connector on though, but if you solder the ends to some insulated wire (I used old Christmas Light Wire) and cut the other ends off clean you usually can just slip the sleeved wire over the pins the insulation of the wire will hold the copper on the pin and then you can test away!

Thanks!

Also, What else can I test at this point? I am still have a feeling that it might be the Caps, could you circle which ones you think I should try replacing, and then I'll get Numbers for those so you can recommend replacements.

[tom66]

Re: Toshibia 40rv525u Green Blinking light and questions about Caps!!

What voltage did the PWR line measure when you were using a resistor to pull it up?

Bad capacitors could cause this but the power supply uses very high quality capacitors, which rarely (but not never) fail.