Toshiba 26AV52R power on problem

[alexanna]

A question about this Toshiba television, # 26AV52R I could not locate a chassis number. I was unable to get any information from Elektro Tanya.
As long as the power plug is not removed from the wall outlet it will power on immediately and work fine.
If the plug is removed from the wall outlet for around 5minuets or so when its plugged back into the outlet when the power button is pushed the Power LED will light for about 1 second and then go out and of course the set will not turn on . After multiple times of pushing the power button the set will turn on and work. As long as the plug is not removed from the wall I am able to power on and off and it works as it should.
The set was built in 2007 and has Rubycon XYF and UC KZE Capacitors They are not bulged.
I have replaced the 6 small Rubycon on the power supply with a mixture of Panasonic FM an UC KZE series capacitors. I am beginning to wonder if there may be a problem with one of the two large capacitors on the power supply.
I will post some photos in the AM when there is some good light.
Does anyone have any ideas?

[alexanna]

Re: Toshiba 26AV52R power on problem

After powering the set off with the power button last night, and still plugged into the wall outlet the set powered on and worked.
I measured voltage to the two large 320V caps and in reference to the picture the lower cap showed 329V, and the 320V cap just above it reads 164V.
I had 5V stand by voltage, and a Pin marked “ower” read 4.2 V as the power button was pushed, and the set powered on. The 24V, and 12v voltages were good.
I removed the plug from the wall outlet and could slowly watch the voltage bleed down on the 320V caps.
After plugging the power cord into the wall socket the large caps voltage rose, to 322.6V and 161.4V
The standby voltage reads 5.046V, But as the power button is pushed the pin marked “ower” only reaches 3.625 This voltage is lower than when the set will power on.
And of course I get no 12V or 24V at any of the pins.
At this point are there any sugestions what i should check next?

[Dgtech]

Re: Toshiba 26AV52R power on problem

This sounds to me like a capacitor problem. It may be hard to find without measuring the capacitors. I try to tell people how to check caps on a fluke meter but most dont have flukes or a stand alone cap meter.

[steve2]

Re: Toshiba 26AV52R power on problem

Those look like they say 200v @330Uf. If you are reading 329v, I would think the cap would blow. That's measured right on the pins of the big caps? The 161.4 at the upper cap seems right for most rectifiers output. The 329 at the lower one doesn't seem right.

[alexanna]

Re: Toshiba 26AV52R power on problem

Those look like they say 200v @330Uf. If you are reading 329v, I would think the cap would blow. That's measured right on the pins of the big caps? The 161.4 at the upper cap seems right for most rectifiers output. The 329 at the lower one doesn't seem right.

Thankyou for calling that to my attention,I didn't look at things closley enough this morning.
I had refrenced the ground from just one of the capacitors,I did not want to have 164V wake me up this morning . When I refrence the ground to each capicator I do read 164V on both of them.

[alexanna]

Re: Toshiba 26AV52R power on problem

I really have no problem replacing capacitors; I most likely have all I need to do the job. The meter I have is able to measure the UF of the capacitors but I do not own an ESR meter.
I am really just trying to make heads or tails of want has to happen for this set to start.
And I understand it may be difficult to do without some type of service manual

I am going to include a picture of what I think may be the IC to start the 24V, or maybe the 12V ? IT is a 16 Pin IC and it looks like it may be some type of amplifier?
AS324AM http://pdf1.alldatasheet.com/datashe...S324AM-E1.html
On the bottom of the board the top 16 Pin connector, The third pin from the left is the “ower” pin I can trace that pin to a resistor R707 which is 5.1K Ohms to a zener diode D605 and to pin #4 of the AS324AM.
Because the set will work when the power pin has 4.2V on it and not when 3.652V, I wonder if there is a way to tell if the signal board is not providing enough voltage or if the ASM 324AM may be causing the voltage to be low?
On D605 the zener diode there is a making T4---and a W3 on it.
Also on the bottom of the board there is a TEA1610 this is on the secondary side.
http://pdf1.alldatasheet.com/datashe.../TEA1610T.html

[alexanna]

Re: Toshiba 26AV52R power on problem

there was ia mistake made in the above post the TEA16120 is on the primary side

[littlegrey]

Re: Toshiba 26AV52R power on problem

Goto wallyworld and in the computer section get a big can of blow off duster spray, take it home and turn the can upside down when u use it and u will have instant freeze spray to like 160 degrees below zero lol its much cheaper than freeze spray and is same thing but u just have to turn the can upside down lol
Anyway if u got a bad cap then that will most likely tell u cause when u hit the bad one the startup voltage will most likely increase to where it should be and the set will come right on,it may take a few mins to find it if thats the problem which it sounds like it is, and if that dont work do it backwards, use the tip of ur soldering iron to heat the caps up and try it that way, however make sure the soldering station is not grounded by a ground plug or use it hooked to a isolation transformer or just bend the ground pin of the soldering station away so its not grounded and just a hint, its prolly a vey small 4.7 at 16volt cap and rarely one of the big ones

[alexanna]

Re: Toshiba 26AV52R power on problem

I hope I am not too premature on this, But I think it might be fixed.
I will leave it unplugged for a while and if it is, I will share

[cadillacman]

Re: Toshiba 26AV52R power on problem

sweet!!

[alexanna]

Re: Toshiba 26AV52R power on problem

I am going to say this is fixed, it sat unplugged all night and when I plugged it into the wall outlet it powers on and stays on.
I replaced on cap on [for lack of better name] the signal board it was a 10V 470UF cap, and 4 470UF ranging from 10V to 35V on the power supply.
So it really turned out to be an easy repair, all of the capacitors were within their UF specs.
I guess one thing I did learn is there are some voltages on the power supply that can really do some serious damage to you, and you have to be really careful there is a possibility you could buy the farm!

[bevis034]

Re: Toshiba 26AV52R power on problem

I am looking for the value of the diode at position TV51 on the board HP-n1331r2 from a Toshiba 26av52r. Mine is burnt.

Thanks, Jeff

[selldoor]

Re: Toshiba 26AV52R power on problem

Do you mean TVS1 ?? can you post a pic of where it is on the board.
It it blown apart if not try cleaning it with isopropyl alcohol.
Please can you update your profile with country and mains voltage