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Equipment Repairs => CRT TV forum => Topic started by: In_Focus on April 29, 2010,15:31:32

Title: JVC AV32H77 ML2 Chassis
Post by: In_Focus on April 29, 2010,15:31:32

Hi. All,
Need some help with this big heavy monster.

Dead set with standby LED flashing. Standby 5Volt supply is correct but the relay does not pull in to energize the degauss and main psu.

Anyone come across this? No mention of a flashing LED error in my copy of the manual.

Title: Re: JVC AV32H77 ML2 Chassis
Post by: Turnip on May 13, 2010,12:00:33

Hi - I-F,

Just a thought - as there is some background on a LO/P short on this model due to a duff cap, which might seem as if supply isn't cutting in, suggest you check LOP for S/C - Chris.

Title: Re: JVC AV32H77 ML2 Chassis
Post by: In_Focus on June 10, 2010,16:02:25

Hi all,

An update on this now that the forum is back online.
Fooled by a DVM :wallbash: :wallbash:. The 5 volt standby supply from IC491 which is a hybrid device was complete hash when checked with a scope. :oops:

I'm now struggling to find someone who has them in stock at a sensible price, suspect this one will end up at local recycling centre.

Title: Re: JVC AV32H77 ML2 Chassis
Post by: Contrast John on June 10, 2010,16:11:40

Hi I-F
Any chance of building a 5volt supply to take its place or is there more to the sby 5v circuit then meets the eye?
Always looking for a cheapo alternative!
Regards
John.

Title: Re: JVC AV32H77 ML2 Chassis
Post by: In_Focus on June 10, 2010,16:43:22

If it was for myself no problems, ln fact I hooked up an external supply to check the rest of the set and CRT but to do this with a customers set  :dubbio: Should be no problems with a transformer, bridge rect, 7805 and a couple of electrolytics but If anything untoward happens in the future with that or any other part of the set you're always going to be on an a sticky wicket with an unauthorized mod, even though you're trying to save them cash.

Title: Re: JVC AV32H77 ML2 Chassis
Post by: Contrast John on June 11, 2010,03:37:50

Hi I-F
Share your concerns and wonder how much of our work could be classed as an unauthorised modification. For example how many of us have linked a cracked bit of print with wire? (different current rating to the print), or soldered the turret back on to a tuner unit where originally it was only crimped on. (some might argue it was designed to break off at the first sign of stress for safety reasons; ie someone tripping over the coax cable). The more I think about it the more I get worried as the possibilities with this 'health n safety' and 'blame culture' are endless. In theory I suppose anything we do to a set could be argued to have in some way altered it from its original spec! Anyone else have a view on this one?
Regards an best of luck scourcing a reasonably priced IC.
John.