[TechAssist] Re: final fix: bad again!,Sanyo DS25330 unusual symptom/fix for dead set,R409 ID?
- From: larry <schntv@xxxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Fri, 12 Nov 2004 09:20:45 -0500
i am happy you got it fixed,
i dont mean to give you a rough time but,
i didnt know a 5 watt wire wound resistor could change value,
in the past i have either found open or right on resistance in
these big ones.
are you sure your ohm meter is ok?
if this is true, i better start looking closer at these
resistors also.
you may have opened my eyes to this.
Larry
Phil Bader wrote:
> Would play hours OK, but turn it off and try turning it right on again
> and nothing.
> After an hour of testing and freeze spray,etc here's the fix:
> The standby power supply that supplies to the relay coil is a network of
> resistors from 1 watt to 5 watts. Three were off value:
> R024, 330 ohm, 1 watt measured 260 ohms.
> R022, 270 ohm 2 watt measured 260 ohms.
> Replaced those two and tho bad, did not cure my problem.
> Final fix was:
> R021, 820 ohm 5 watt square ceramic. Measured 1000 ohms.
> Aparently, as the set ran, these resistors collectively heated up and
> further changed value,lowering the amount of standby voltage at the
> power relay solinoid. If running, no problem, but turn it off and not
> enough juice to re-energise the relay to turn on again til cooled off.
> Dang this was a hair puller.
> Phil Bader
>
> Phil Bader wrote:
>
>
>>Thought I fixed this problem with the STR30130 IC.(see original thread
>>below)
>>Ran all day. Turned it off, then tried to turn it on. No go. Same issue
>>as before. Dead. I am replacing C007 (4.7@160V) and R005 (220K) both ib
>>the PS near the str30130. Maybe they go bad under load, or warm.
>>I also have a 2 watter R409 I pulled and need to check:. Reads about 7K
>>but I need it's value.
>>Thanks.
>>Phil Bader
>>
>>Phil Bader wrote:
>>
>>
>>
>>
>>>Originally set was said to be dead after storm. Tho it powered up OK on
>>>the bench, there were many,many bad solder connections and overheated
>>>areas of the board. Thoroughly resoldered, tested, and sent home.
>>>Customer said it never did run at home after repair. Customer returned
>>>it. Plugge it in. Ran good immediately. Powered on with my remote
>>>(customer has none) and with the front power button OK.
>>>I plugged it into the power strip on the test area and dead. Plugged it
>>>into my Sencore PoweriteII PR570 isolation transformer , and also dead.
>>>Even tried increasing/decreasing the line voltage.No help.
>>>Plugged it back in on the bench, works!
>>>Here's the thing:
>>>My bench uses a single outlet 1:1 isolation transformer that I always
>>>plug in the TV under test. The set WORKS with that isolated outlet.
>>>Plugging in direct into the UN-isolated power strip next to it DOES NOT
>>>let it power up. My Sencore PR570 DOES NOT let it power up.It's
>>>isolated! Only my small 1:1 isolation transformer at the bench lets it work.
>>>I replaced the STR30130 regulator, and problem cleared. Fixed! Note: The
>>>old str30130 outputted exactly +130 volts DC with perfect picture.
>>>Now I would understand it working with the isolation and not the direct
>>>wall outlet,(leakage) but wouldn't even power on with my Sencore
>>>isolation unit. Strange.
>>>Phil Bader
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>
>
--
Schneider TV & Electronic Inc.
5415 N. Wooster ave.
Dover, Ohio 44622 www.geocities.com/schntv2000/
330-343-0768 FCC. first class & Extra class K8WLY
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