Sony XBR65X850B stuck in endless reboot loop: harware or mushware?

[OTH1]

(Hi from a brand-new Videokarma member; this is my first post here, and I hope it's in the proper forum.)

Knowledge, advice, and guidance is sought re a 65 in. Sony Bravia TV now stuck in a non-stop fast reboot cycle at turn-on:

The set is a model XBR65X850B, s/n 5447679 LCD TV, purchased in Dec. 2014 by my daughter in California. I'm in New Jersey and limited to remote help, IF there's any help to give, hence my calling in the Videokarma rescue squad.


Diane reports:

This 65 inch TV worked very well for over 5 years. It had always connected to the outside world via an old, slow Frontier DSL modem -no FiOS in her area; Frontier always had a lot of problems. As she lives in the hills above Santa Barbara, no better access was available until last week when Cox installed a new line and fast modem.

Life with new fast cable was indeed good until the TV crapped out a couple of days later. That ISP/service change might or might not have something to do with this failure mode.

The set will power up, and immediately shut down, never progressing to audio or video. It does so repetitively, the only noise being relay clicks near the AC input at the back of the set. The power indicator LED continuously toggles from red to green to red to green, each cycle taking several seconds until the set is unplugged.

She disconnected the TV from everything, AC included and let it sit for many hours, more than once. Same symptoms appear whenever AC is applied. Can't do a hard (factory) reset, with no display of course.

Yep, it may well be a power supply issue or some other hardware trouble, but mistrusting Sony, I suspect something else:

- Only after Cox installed a fast bi-directional modem could that smart TV connect to the Sony Mothership. I think the TV couldn't announce its presence to Sony previously via the ADSL, but may have done so via the new fast bi-directional ISP. I'm guessing Sony might have pushed a firmware/software update to it soon after the set appeared on the Internet. My daughter has no way to know. Neither of us contacted Sony due to bad tech support experiences with other products.

I have no information yet re any wireless (WiFi) router that Cox may have installed and enabled, but will try to get it turned off, if present.

There's mention on-line in Sony XBR blogs re endless reboot loops after automatic "updates", most of which couldn't be fixed even by on-site Sony techs. Apparently at least some of the updates commonly resulted in a FUBAR main board, with a class-action threatened in 2016, to no avail. Some sets were replaced under warranty. Sony turned their beyond-warranty customers into enemies.

Diane and I each downloaded the OEM user manual; it offers nothing helpful, referring to the more comprehensive on-screen manual allegedly stored in the set's memory. No user-level diagnostics seem available for this situation.

We each searched Sony's on-line sites, and I dug around the Internet appreciably before I realized someone here might have seen this problem.

My daughter has nothing beyond a multimeter; lacking service data she'll stay out of the set. Pretty sharp, but not really into electronics, Diane might change boards if needed, but this problem is hard to deduce just by observation.

Power supply modules as are $40-100 depending on who you trust. Before rolling those dice. I'm hoping a Videokarma member might offer some insight, even if only an educated guess. That fancy, overpriced set cost something like $3,400 new five years ago, and at ~$700/year that's not a very nice amortization.

Sure, nice big modern non-Sony TVs can be had at COSTCO and elsewhere for $650 these days and better ones for more. Money is tight, so she'd prefer to keep this set if it's economical to fix. Any suggestions?

"Use it up, wear it out, fix it, make it do, or do without...." still informs us, but is Sony making her do without?

Please help me to help my sweet, hardworking daughter 2,800 miles away.



Thanks for reading and considering all this,

John, aka "OTH1" here and as "OTH" on Antique Radio Forums.


ps- I posted a similar message there, but expect no constructive help from the old radio group.