Repairing NEC nlt-32xt2 lcd tv - diode id

[abaddonxi]

Hi all, new to the forum and looking for some help.

I'm repairing the power supply on my flatscreen and can't identify the offending diode. I'm only up to the skill level of working out which component looks burnt and replacing it, and this one has me stumped.

The diode is marked d508 on the board and has the letters, RUIP EADA ,written on it. I've done a fair bit of looking but can't find anything that might match with my limited skills.

The lozenge cap in the larger pic is also toasted - 474J 400v

Thanks
Simon

Pics-

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[leal]

If I recall this could be a avalanch diode (Zener diode,about 150v), it is used to protect the circuit in event of exsess voltage. Usually it will be parralel to the circuit and some times it will open up or short.

If it was a reg diode it will perhaps have a .001uf paralel with it for sw noise.

 

[tunedwolf]

The diode you are looking at is an Ultra Fast Recovery Rectifier rated between 600 and 1000V made by Sanken and Rhom amongst others.
It is actually marked as RU 1P, although that might not be so obvious from the stamping.
Diodes really only fail in smps when there is a critical over current, your problem will not be limited to this one diode only. Pay particular attention to the chopper FET, smps driver chip, all associated resistors and diodes and replace all of the small electrolytic capacitors in the power supply before you apply power again.

rgds

 

[abaddonxi]

Thanks for that.

I tested the diode with a MM and had one-way current, so put it back together, cleaned up the solder joints and powers up.

Works fine on external source, TV tuner has vertical ghost lines and not looking too crisp, so I guess I'll be looking further.