Toshiba 42rv530u wont power on

[budm]

Re: Toshiba 42rv530u wont power on

It should be in thousands of Ohms if it is good.
Boosted Voltage of 400VDC divided by 16 Ohms = 25A! or 10A when it is in standby mode.

[bleed4me]

Re: Toshiba 42rv530u wont power on

Ok same page now...thanks
Time to order a new one...
Maybe ...Digikey cant seem to find it and cant help...

[vinceroger69]

Re: Toshiba 42rv530u wont power on

http://www.ebay.co.uk/itm/PE0546-PE0...-/111096248347

[bleed4me]

Re: Toshiba 42rv530u wont power on

Thanks vinceroger69 for the link. Just curious what do the last 4 numbers mean on the IC and do they have to match? Ebay has a bunch of STR-Z2589 but none match the last 4 digits of mine.

[vinceroger69]

Re: Toshiba 42rv530u wont power on

I guess it could be a date code etc? im not sure yes i did see the ones fron china on ebay but i wasnt sure if these was brand new items or ones pulled and cleaned up etc.

[bleed4me]

Re: Toshiba 42rv530u wont power on

New part is in and just wanted to let everyone know that it was a success! TV is up and running and looking great. Just want to say thank you everyone for your valuable input on this, it is much appreciated.

[dick_barton]

Re: Toshiba 42rv530u wont power on

Well done. Thanks for the feedback.

[budm]

Re: Toshiba 42rv530u wont power on

Thanks for the follow-up on the repair.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

Good evening, I am testing my Toshiba power supply board also. The TV will not turn on or give me a red light for standby volts. It reads 115 Volts on the power cord when plugged in. Both fuses are good and the bridge rectifier gives me 400-700 ohms when I test it. The only thing I think it could be at this point is the large cap in the middle, it is a nichicon 220uf at 450v. It is slightly bulged but hard to tell honestly because of its size.

There are also two other caps that have what to appear to be either brown dots or marks made with a marker on them. One is at the C876 position and one is at the C878 position.

Any help would be appreciated. I admit I am inexperienced, and I may have overlooked something. However, this situation has me scratching my head.

[nomoresonys]

Re: Toshiba 42rv530u wont power on

Any bulge at all replace it, it will either be absolutely flat or bulged, a lot of people replace all the caps while they are in there so as not to have to replace more shortly.

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

Ok, I was having trouble finding a suitable replacement. Where is a good source? I believe the link below is compatible with the 220 uf 450v cap. There is also a white resistor at R850 that will not give me a reading when I check continuity. It simply displays one on my millimeter.

Thanks

https://rover.ebay.com/rover/0/0/0?m...2F391687478404

[nomoresonys]

Re: Toshiba 42rv530u wont power on

Well I shop ebay too, it's always a risk, digikey is a go to site, as a rule if a resister measures funny in circuit, unsolder one leg and test it out of circuit.

[R_J]

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

[nomoresonys]

Re: Toshiba 42rv530u wont power on

You want to check resister in ohm setting. video tute here. https://www.youtube.com/watch?v=v8psOCkN-OQ

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

Hmm, I've added up everything and it would cost me about 20-30$ for all the capacitors and flux. There's a used board for $40, and I'm honestly very inexperienced. It may be a good learning experience though. I'm just going to have trouble finding the time to actually do it. Hmm, if I could get it to fire up with the $10 caps, I guess I could justify spending a little more to fix a few other things. It's kind of a gamble either way.

[Heavyarms92]

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

I believe I will have to desolder R850 I can't get a reading. What should SR81 read? I am getting about 270 on conductivity for SR81

[Heavyarms92]

Re: Toshiba 42rv530u wont power on

You want to check resister in ohm setting. video tute here. https://www.youtube.com/watch?v=v8psOCkN-OQ

Yes, this makes sense no wonder I can't get a reading.

[Heavyarms92]

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

[R_J]

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.

[Heavyarms92]

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.