Beko Z1.194-06 PSU

[sydmichel]

I have been given an OKI LCD TV that is faulty the guy was going to throw it away because someone told him it needed a new power supply. I have powered it up and right enough it does not seem to come on and the power led on the front panel remains red. However, after a few minutes the tv displays "P 50" in the top right of the screen. not sure what that means? Page 50 of the manual perhaps or maybe an error code. At least it proves that the screen and video processor are working I suppose.

I have removed the back and inside the main board is a BEKO Z1J19or-08 and the PSU is a Beko Z1.194-06 PSU. Measuring the voltages The 24V output is steady on 24V and initially before pressing any buttons the 12V output is at 11.96V (standby power I think). On bringing the set out of standby by pressing P+ or P- on the side, The 24V remains steady, but the 12V jumps to 15V! My question is, does anyone know if the 12V rail is supposed to jump to 15V and if not, would this prevent the set from functioning correctly.

I have also noticed 3 bulging capacitors on the Main board C465, C467 and C507 these are all 220uF 25 volt caps. I tried removing these caps for test but there is quite a lot of heat dissipation in the main board and my soldering iron is not up to it.

[Pentium4]

Re: Beko Z1.194-06 PSU

Bulging caps wreak all kinds of havoc in any circuit, so I would fix that main board before you suspect the PSU is bad too

[sydmichel]

Re: Beko Z1.194-06 PSU

Yes thanks for that but I am more concerned about the PSU first because it is putting out 15V where as far as I can tell it should be 12V. This over voltage may be the cause of the failed caps. So far I have tested all the "passives": electrolytics, resistors and diodes on the PSU all seemingly good.

[ben7]

Re: Beko Z1.194-06 PSU

Yes thanks for that but I am more concerned about the PSU first because it is putting out 15V where as far as I can tell it should be 12V. This over voltage may be the cause of the failed caps. So far I have tested all the "passives": electrolytics, resistors and diodes on the PSU all seemingly good.

The 12v rail might be unregulated. When another rail needs more power, the controller does so, but it also causes the 12v rail to rise.

What brands of capacitors are in the psu?

[sydmichel]

Re: Beko Z1.194-06 PSU

The 12v rail might be unregulated. When another rail needs more power, the controller does so, but it also causes the 12v rail to rise.

What brands of capacitors are in the psu?

Sorry for delay

I see, so perhaps a partial short or a breakdown in resistance on the main board could be causing the 12V rail to increase to 15V to maintain the subsequent rise in current.

The PSU capacitor brand is G-LUXON