Zenith HDV420 Won't Come Out of Standby

[gfgray]

If you have a Zenith HDV 420 HD STB and all you have is the red standby light which will not turn green, this is the workaround. Jumper the red wire going between the power board and the main board to the gray wire right next to it.

The limitation of this fix is that if you ever hit the power button, you will have to pull the plug and plug it back in before it will give you the green light again.

[aliasdck]

Re: Zenith HDV420 Won't Come Out of Standby

I am curious what the red and gray wires you have jumped together are labelled as on the powerboard. I can't make it out from the picture. I don't want to jump to any conclusions without understanding why this "fixes" the problem but it may not be such a good idea to override any safety features that have been designed into this tv.

[gfgray]

Re: Zenith HDV420 Won't Come Out of Standby

It is actually a set top box to be used with HDTVs that don't have an HD tuner built in. This workaround is just tying 5V or whatever into the "wakeup" wire. I don't recall what exactly they are labled. I think it has more to do with energy saving than with safety. I think this prevents the power supply from going into energy saving mode and shutting down certain power circuits.

[Wizard]

Re: Zenith HDV420 Won't Come Out of Standby

Are you certain this power supply and mainboard had capacitors replaced before trying this trick?

Cheers, Wizard

[NxB]

Re: Zenith HDV420 Won't Come Out of Standby

You're forcing the backlight on, this could end badly.

[gfgray]

Re: Zenith HDV420 Won't Come Out of Standby

No capacitors were replaced on the power board. I was going to start guessing as to which caps needed to be replaced. But then I tried this. I posted in case someone else on the internet has the same problem.

NxB, please note that a set top box tuner does not have a screen and therefore does not have a backlight. Am I the only person that knows what a set top box is? lol Anyway it has been humming along nicely for like 4 months - except when someone hits the power button.

Edit - I think I measured only a few mA flowing through my jumper in case anyone is concerned that something is seriously shorted out.

[aliasdck]

Re: Zenith HDV420 Won't Come Out of Standby

I over looked the fact that you were talking about a set top box and assumed you were talking about a tv.

[NxB]

Re: Zenith HDV420 Won't Come Out of Standby

same here.

[gfgray]

Re: Zenith HDV420 Won't Come Out of Standby

np, hopefully all the free bumps will make it easier to find for the next person who has this problem

[Scotcho]

Re: Zenith HDV420 Won't Come Out of Standby

This worked perfectly for me. My HDV420 won't turn on either and replacement boxes are expensive. I used a small resistor that I had around the house to make the jumper. Picture attached.

[gfgray]

Re: Zenith HDV420 Won't Come Out of Standby

This worked perfectly for me. My HDV420 won't turn on either and replacement boxes are expensive. I used a small resistor that I had around the house to make the jumper. Picture attached.

Thanks for the feedback Scotcho. You are smarter than me to use a current limiting resistor for safety instead of a jumper.

As an update, this trick eventually stopped working on my box after many months. I tried replacing several of the large SMT caps on the mainboard, but it did not help. So I ended up tossing mine. Too bad, because I could have loaned you my power supply board to see if the problem is with it or with the main board. When yours finally dies, hang on to it until someone else replies to this thread.

Gordon

[Scotcho]

Re: Zenith HDV420 Won't Come Out of Standby

Well, I went to use my set top box for the playoff games yesterday and no lights. It's given up the ghost. I'll keep it around for a while on the shelf to see if any other suggestions to revive it are posted.

[Yellowstone22]

Re: Zenith HDV420 Won't Come Out of Standby

This worked perfectly for me. My HDV420 won't turn on either and replacement boxes are expensive. I used a small resistor that I had around the house to make the jumper. Picture attached.

I tried this and it worked Great. Thanks for taking the time to post this fix

[gfgray]

Re: Zenith HDV420 Won't Come Out of Standby

I tried this and it worked Great. Thanks for taking the time to post this fix

If you and Scotcho are willing, the next step is for Scotcho to send at least his PSU and maybe also his motherboard to you before your unit fails completely. Then, you can swap parts out and see if the issue follows the PSU or motherboard.

Gordon

[escheids]

Re: Zenith HDV420 Won't Come Out of Standby

I know this is an old thread, but I have(had) the same problem. I didn't like the idea of jumping across the wires but I tried it and it worked. The new news is that I removed the jumper when it powered on and it stayed on, and I was able to off/standby/on again without the jumper several times. I don't know how long this will last, but maybe someone with more electronic experience can debug with this new info.

[gfgray]

Re: Zenith HDV420 Won't Come Out of Standby

I know this is an old thread, but I have(had) the same problem. I didn't like the idea of jumping across the wires but I tried it and it worked. The new news is that I removed the jumper when it powered on and it stayed on, and I was able to off/standby/on again without the jumper several times. I don't know how long this will last, but maybe someone with more electronic experience can debug with this new info.

That info doesn't give me any more ideas. It will probably stop working if you unplug it. I would recommend that you ask scotcho to send you his power supply board (or you can send him yours) to see if the problem is with it or with the main board. Then whichever one of you can, start testing at the component level.

[ColoradoSky]

Re: Zenith HDV420 Won't Come Out of Standby

Thank you gfgray and Scotcho! This worked for me. Thanks for the pictures, they really helped.