Hitachi 55hdx62

[mrosenberg42]

I have a Hitachi 55hdx62 that will not power up. The power supply shuts down in about 1/2 a second after pushing the power button. I have gone through almost all components on the power supply the x sus and ysus boards. Their are only two that I am suscpicious of. One smd aluminum electrolytic cap and a much larger cap. I cannot find any data sheets on either capacitor. The markings on the small smd cap are 5J 22 JLD. I also tried to find a data sheet for the other larger capacitor. But when I do a google search I get nothing from the part number on the cap. The large capacitor measures an ESR of 32 ohms and the small looks to be 22uf capacitor has an ESR of 3.2ohms. If anybody could help me identify either capacitor that would be really appreciated. I attached the pics of the caps I'm looking for. Thanks.

[Wizard]

Re: Hitachi 55hdx62

That is poly (not polymer) cap drop. 43nF in size 1.25kV That's certainly found in the horizontal deflection circuit. Not dependent on ESR. It is special application and usually it doesn't fail very often, if it does, it burst open or burned.

The SMD cap is 22uF as you thought. Voltage is denoted as a letter, that one is 6.3V by this J.

Keep looking, this is not quite the issues.

Cheers, Wizard

[mrosenberg42]

Re: Hitachi 55hdx62

Thanks Wizard. The poly cap is actually in the early stage of the power supply. Would the power supply be fairly sensitive to esr? Also how did you know it was a 43nF cap? Is their a database to find these values? the smd cap is located on the main digital board. There is another one of the same caps that measures an esr of .42ohms while the suspect one reads 3.2ohms. Thanks for the info.

[Krankshaft]

Re: Hitachi 55hdx62

If the PSU is shutting down quickly and there are no cap problems then most likely it's a protection circuit kicking in.

Probably due to a faulty component shorted out (drawing too much current) on one of the rails.

A schematic of the power supply section would be helpful. Since it's a Hitachi and not a Chinamart brand this shouldn't be hard to obtain.

[PlainBill]

Re: Hitachi 55hdx62

Thanks Wizard. The poly cap is actually in the early stage of the power supply. Would the power supply be fairly sensitive to esr? Also how did you know it was a 43nF cap? Is their a database to find these values? the smd cap is located on the main digital board. There is another one of the same caps that measures an esr of .42ohms while the suspect one reads 3.2ohms. Thanks for the info.

Searching for 'capacitor labeling' or 'capacitor codes' will bring up may pages of information. One example:

PlainBill