Akai CT-T25PA3A - value of R2050

Sorry group. I forgot to mention that I could find no cause for the resistor burning up. Can anyone suggest what might have caused it to happen.

Russell Griffiths

Hi,

From experience, use 10R resistor. Original is 100R and it goes. I think, slight aging of the tube causes current increase and 100R gets cooked. 10R seem to survive for longer.

Just in case, check soldering on the RGB amplifiers and electrolitic capacitor in 130V line, but resistor should be the only fault.

Rudolf

Thanks for the reply Rudolf. Would I be right in thinking it should be a fuseable 10ohm resistor?

Thanks, Russell.

I do not think it really matters. If something in RGB amps circuitry dies, even non-fusable will blow, although it would take longer and will be some smoke.

I am pretty sure original was not fusable anyway.

Rudolf

I put in a 10ohm 1/4watt, and it started to smell straight away. After 2 hours use, the tv is still working but the resistor is a little bit dark.

I have ordered a 10ohm 1/2watt fuseable resistor.

Russell.

On 27 Mar 2007 01:51:55 -0700, "Griff" put finger to keyboard and composed:

If a 10 ohm resistor is dissipating more than 1/4W, then the current must be more than 160mA. This means that the 130V supply must be delivering more than 20W of power to the CRT neck. Does this make sense? Furthermore, since the beam current is never (?) more than about 1mA, this suggests to me that something is seriously wrong.

- Franc Zabkar

Thanks for the contribution Frank. I have put in the 1/2 10ohm fuseable resistor and tested the tv for 18 hours. So far everything seems fine.

I don't know what else I can do.

Russell.

On 5 Apr 2007 00:06:19 -0700, "Griff" put finger to keyboard and composed:

Try a bright white test pattern at max contrast. That should be a worst case scenario.

Measure the voltage across the resistor? Check whether any of the RGB amps run hotter than the others?

- Franc Zabkar

I did not go too deep into it. Friend does warranty work for AKAI and says that changing value of resistor fixes the TVs and they do not come back.

Rudolf