Acer B326HUL power supply dead

[fred41]

Re: Acer B326HUL power supply dead

Hi, I finally gave up and payed a repairmen to repair it...

[the.norbulus]

Re: Acer B326HUL power supply dead

Thanks for the reply You're back up and running now which is the main thing. I hope it didn't cost you too much.

[fjaffre]

Re: Acer B326HUL power supply dead

It's very difficult to read anything in here but it seems like the PFC/quasi-resonant flyback controller is NXP, possibly TEA1751T. According to the datasheet, the startup voltage is 21-23 V so when it's at 18-19.6 that's too low.

The path goes from the auxiliary winding on primary side through inductor to an SMD diode, capacitor and than there is "K415 C200" TO-92 bipolar transistor. The 15V feed leads to its collector, the oscillating 18-19.6V output is on its emitter. Collector and base has 1002 SMD resistor in between and base is also connected through an SMD zener to return.

So it seems like some amplifier with zener feedback? And this is to feed the Vcc of the controller.

Bonjour à tous, je recherche de l'aide pour réparer mon écran ACER B326HUL. Le problème semble venir de l'alimentation, aucunes tensions en sortie.

J'ai contrôlé les tensions sur le transistor K434 C200. Sur la base et le collecteur j'ai 11v et l'émetteur 17v. Vous dites que le circuit TEA1751T démarre à partir de 21-23v.

Je ne parviens pas à comprendre d'où vient le 11 volt et donc de trouver pourquoi j'ai si peu. J'ai mis la photo sur casimage pour avoir une meilleur définition : https://nsm09.casimages.com/img/202...20717115189.jpg

Si quelqu'un peut m'aider, je le remercie d'avance.

Hello everyone, I am looking for help to repair my ACER B326HUL screen. The problem seems to come from the power supply, no output voltages.

I checked the voltages on the K434 C200 transistor. On the base and the collector I have 11v and the transmitter 17v. You say the TEA1751T circuit starts from 21-23v.

I cannot understand where the 11 volt comes from and therefore to find out why I have so little. I put the photo on casimage to have a better definition: https://nsm09.casimages.com/img/202...20717115189.jpg

If anyone can help me, I thank them in advance.

[fjaffre]

Re: Acer B326HUL power supply dead

Bonjour à tous, je recherche de l'aide pour réparer mon écran ACER B326HUL. Le problème semble venir de l'alimentation, aucunes tensions en sortie.

J'ai contrôlé les tensions sur le transistor K434 C200. Sur la base et le collecteur j'ai 11v et l'émetteur 17v. Vous dites que le circuit TEA1751T démarre à partir de 21-23v.

Je ne parviens pas à comprendre d'où vient le 11 volt et donc de trouver pourquoi j'ai si peu. J'ai mis la photo sur casimage pour avoir une meilleur définition : https://nsm09.casimages.com/img/202...20717115189.jpg

Si quelqu'un peut m'aider, je le remercie d'avance.

Hello everyone, I am looking for help to repair my ACER B326HUL screen. The problem seems to come from the power supply, no output voltages.

I checked the voltages on the K434 C200 transistor. On the base and the collector I have 11v and the transmitter 17v. You say the TEA1751T circuit starts from 21-23v.

I cannot understand where the 11 volt comes from and therefore to find out why I have so little. I put the photo on casimage to have a better definition: https://nsm09.casimages.com/img/202...20717115189.jpg

If anyone can help me, I thank them in advance.