Hitachi 42HDS52 When powers off has to unplug to power on

[R_J]

Re: Hitachi 42HDS52 When powers off has to unplug to power on

Test Tv is Hitachi 55HDT52
I tried the test procedure on my power supply (power supply removed from tv), the Vs & Va come up for 3-4 seconds then start to drop off, I guess without a load they will not stay on.
I connected a 110 v 60w lamp to the Vs and ground and the power supply stays on, with 88 volts across the lamp, voltage on Vs without load was around 93 volts
So a load is required on the Vs line to keep the power supply Vs & Va on

[jason123]

Re: Hitachi 42HDS52 When powers off has to unplug to power on

Thanks for verifying the Vs / Va functionality.
Just a quick update - I took the metal shrouds covering the main board and logic board, and you're right R_J, it must have been a loose connection, or massive amounts of dust under the RF Shields.. once I vacuumed and put back together, it fired right up and several times after that. I learned a lot from you and Thank you for sharing and educating me.

I found, that the label on my panel is calling for lower voltages than the power supply is pumping out on Vs and Va, by about 1.5-1.8 Volts.. I adjusted those down to match the panel sticker. Hope that's not messing things up in the near future. Manual has the procedure for adjusting the voltages, but calls for "Pre-Heat Run" and burn-in screen which I didn't know how to get to

[R_J]

Re: Hitachi 42HDS52 When powers off has to unplug to power on

Just adjust the Vs & Va after the set has been on for 1/2 -1 hr they won't change that much. and they really arn't that critical. You could unplug & plug in the cables just to make sure they are seated properly and also by doing that it kind of cleans the contacts a bit. Hope it stays running

[jason123]

Re: Hitachi 42HDS52 When powers off has to unplug to power on

So far so good R_J.. Thanks for the help!