[TechAssist] final fix: bad again!,Sanyo DS25330 unusual symptom/fix for dead set,R409 ID?
- From: Phil Bader <tjanphyl@xxxxxxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Thu, 11 Nov 2004 16:55:16 -0500
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
>>
>>
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>>
>>
>
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>
--
Philip Bader
Jan Phyl TV Inc. (estab. 1976)
3420 Recker Hwy. Winter Haven, Fl. 33880
Fax (863) 299-8821
email: tjanphyl@xxxxxxxxxxxxxxx
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