Toshiba 42rv530u wont power on

[budm]

Re: Toshiba 42rv530u wont power on

Ok, so if I am understanding everything correctly. SR81 seems to be the main suspect here. I will check all 4 pins next.

Also, everytime I check R850 all I get is 0 ohms. I know I should get 1.8 though. I will more than likely unsolder it and check it to be sure. If that's wrong correct me, there may be a trick that I haven't learned yet, or just poor technique on my part.

What Ohm scale were you using? What does your meter show when you touch the two meter probes together, that will be the lowest resistance you should see unless your meter has ability to ZERO out the meter probe to get the meter to show 0 Ohm.

[nomoresonys]

Re: Toshiba 42rv530u wont power on

It is not going to be the lagre cap, many times they look bulged but it is just the plastic top that is bulged a bit, if you can press it flat the cap is very likely ok.
If R850 is open it is caused by bad contacts on relay SR81 in standby low current flows through the resistor, when the tv is turned on the relay shorts the resistor so the higher current bypasses the resistor, If the relay contacts are bad, as in open, ALL the current flows through the resistor, it heats up and opens its internal fuse.

This is a very common problem

Ok, looks like he needs to replace SR81.

[nomoresonys]

Re: Toshiba 42rv530u wont power on

Just for curiousity would the board below be compatible? It is for my television but not the same board number. I don't think it would fit but it might. Safety is my primary concern though.

https://rover.ebay.com/rover/0/0/0?m...2F273236805950

Yes that is a match, you could try replacing SR81, that won't cost more than a few bucks.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

You don't need to unsolder R850, if it is good it would read close to a short (1.8Ω) , the relay should be replaced or taken apart and at least clean the contacts (this cant be checked with your ohm meter)
SR81 has 4 pins, two are for the coil and 2 are the contacts, the 230Ω is likely the coil resistance.

I believe the coil is consistently giving me 267 ohms, and the contacts are at 0 when checking capacitance. Am I doing anything wrong? I've checked on AC and DC.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

What Ohm scale were you using? What does your meter show when you touch the two meter probes together, that will be the lowest resistance you should see unless your meter has ability to ZERO out the meter probe to get the meter to show 0 Ohm.

I'm using an older Simpson 467E, and it measures 0 when I touch the two leads together on AC and DC for capacitance. The leads on my little read harbor freight multimeters ripped themselves off of their respective wires when I picked up the unit on 2 different occasions. I'm not sure how to crimp them back on...

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

Yes that is a match, you could try replacing SR81, that won't cost more than a few bucks.

I will try that. If it pops will that mean I need to go back to the bridge rectifier? It checks out per the TampaTech video that I've watched regarding Toshiba Tvs. It measures between 400-600 ohms consistently when checking capacitance.

[R_J]

Re: Toshiba 42rv530u wont power on

I believe the coil is consistently giving me 267 ohms, and the contacts are at 0 when checking capacitance. Am I doing anything wrong? I've checked on AC and DC.

It a RELAY not a capacitor! A relay is basically just a switch activated by a coil.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

Yes that is a match, you could try replacing SR81, that won't cost more than a few bucks.

The components at this position appears to be a switching relay. The component reads GEC C183 TYPE DG1U 12VDC III coil 12 volt 8A 250V 8A 30V. I have tried to google a replacement but I have had no luck.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

It a RELAY not a capacitor! A relay is basically just a switch activated by a coil.

Ok, so should I be checking Voltage and not Ohms? Sounds like it should be 12 Volts, but it's not plugged in.

[R_J]

Re: Toshiba 42rv530u wont power on

To check the resistor you put your meter in ohms, in the lowest range and place the probes across R850. It should produce the same reading as if you connected the probes together. The reading should be near 0 (actually 1.8Ω)

If the resistor R850 is open it is because the relay contacts are bad. The contacts are burnt. The problem is not with the relay's coil
Because the resistor is open you will not have any standby voltage.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

To check the resistor you put your meter in ohms, in the lowest range and place the probes across R850. It should produce the same reading as if you connected the probes together. The reading should be near 0 (actually 1.8Ω)

If the resistor R850 is open it is because the relay contacts are bad. The contacts are burnt. The problem is not with the relay's coil
Because the resistor is open you will not have any standby voltage.

Ok, so if I unsolder it and resolder it you think it will go? When I tested it earlier it was 0 ohms, would that mean it was open? I need to get some flux then, I think I am out unfortunately.

[budm]

Re: Toshiba 42rv530u wont power on

0 Ohm = Resistor has NOT gone open circuit.
What kind of spare parts do you have? Do you have any resistors?

[budm]

Re: Toshiba 42rv530u wont power on

Meter user manual: https://cdn.badcaps-static.com/pdfs/...6d86336230.pdf

[budm]

Re: Toshiba 42rv530u wont power on

BTW, I would like to suggest you to plug the TV into GFCI outlet to protect yourself, and do not touch anything on the power supply board while the TV is plugged into the AC outlet.

[budm]

Re: Toshiba 42rv530u wont power on

SR81 12VDC RELAY: see post #15
https://www.badcaps.net/forum/showth...highlight=SR81

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

0 Ohm = Resistor has NOT gone open circuit.
What kind of spare parts do you have? Do you have any resistors?

Honestly none, I will have to order some, I was just trying to figure out what I needed and where to start. I have done some electrical work but not much with pcbs. This is a new frontier for me.

I do have a 12v power supply though. I have no idea how to use it but I have seen guys testing things with them.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

BTW, I would like to suggest you to plug the TV into GFCI outlet to protect yourself, and do not touch anything on the power supply board while the TV is plugged into the AC outlet.

I will make sure to use one of these, I don't like the idea of getting shocked.

[R_J]

Re: Toshiba 42rv530u wont power on

So now the resistor R850 is NOT open? If it measure 0Ω then your fault is somwhere else
with power OFF, check the rsistance of the fuses F820 & F840.
If you feel comfortable working on this with power applied...
Measure the DC voltage accross C820 (220uf/450v) If there IS voltage is it 160v or closer to 400v?
Keeping your negative probe on the (-) of C820, check the voltage on both sides of the fuses, F820 & F840. IS there voltage on both sides of these fuses

[nomoresonys]

Re: Toshiba 42rv530u wont power on

Ok, so whats the status of the filter cap, bulged or flat?

[nomoresonys]

Re: Toshiba 42rv530u wont power on

Did you test the bridge rectifier and voltage regulator?