RCA AP52X standby power flicker - Videokarma.org TV - Video

MIPS · #1 03-04-2015, 10:11 AM

So for another project I gutted out what remained of what I assume was once an RCA rear projection set. Best I can find is the model AP52X/AP5X stamped in various places. Anything in the cabinet or on the boards that might or given me a solid idea of the make and model was too damaged by the weather to recover. It must of been out there for at least six months.

Anyways, after a good cleaning and time to dry it was reassembled and seems to be functioning fine aside from one thing. When the set is in standby mode the high voltage chirps and all the voltage status LED's flicker like the set powers up for a split second, then turns off. Even the Power LED does this. The moment you power the set on however it goes away and the set never slips up. Once you put it back to standby however it goes right back to doing it.
Seeing how it can come out of standby with no issues I'm assuming the standby power is fine however something keeps making it kick on and then remember it should be off or something. I got no ideas at the moment. You guys got any? Also, if anyone knows where I MIGHT find some form of service documents listing what that giant array of adjustments do, I'd love to see it.

Edited: Nope, it's a Hitachi set. See below.

Findm-Keepm · #2 03-04-2015, 11:19 AM

You have a Hitachi 50EX14BV pictured, AP52 Chassis. PM me for a manual. Dunno what the problem is, I just have the manual.

Cheers,

MIPS · #3 03-04-2015, 11:50 AM

I should of clued in to Hitachi when I saw who made the tubes.

Okay, I'll send you a PM.

rca2000 · #4 03-04-2015, 01:27 PM

Some Hit projo sets DO "chirp" the HV at power up...for a few seconds. As long as the HV does NOT stay on--likely ok. Those status indicators show your standby voltages. they may be "somewhat dim" compared to run--this is because the power supply is placed in a "low tide mode" in standby--to reduce power draw. When powered on--ALL of green the status LED's should come to full brightness--along with the HV.

MIPS · #5 03-04-2015, 09:38 PM

So then why is it chirping over and over again? It sure doesn't feel like it left the drawing board like this.

rca2000 · #6 03-04-2015, 10:09 PM

Not sure what you mean by that. If you mean "it continues to chirp" in standby--that is NOT correct. It should do so ONE time--and then go silent--til powered on. Almost sounds like some sort of over voltage/current limiting ckt being tripped.

MIPS · #7 03-06-2015, 11:52 PM

Yeah, it just chirps over and over, making all the voltage rail LEDs to flicker.
I also assumed it was a safety circuit engaging the first time I plugged it in because I had never tested it before but as observed, power is well enough that the set can be turned on and it never kicks out for any reason.