[TechAssist] Re: VS4551 mitsubishi ,no power up when cold: only thump-thump. still not fixed
- From: "al m" <ampm@xxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Sat, 5 Mar 2005 12:00:37 -0500
Yeh anything that is a cooling problem will be brought out with the spray.
Just an idea, try turning it off and spray the parts then try turning it on.
Could be a cap that is not charging fast enough when it's cold, sort of a
double whammy.
Al Marquardt
ampm@xxxxxxx
Al Marquardt Electronic Repair
206 W Main
Girardville Pa. 17935
----- Original Message -----
From: "Phil Bader" <tjanphyl@xxxxxxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Saturday, March 05, 2005 11:36 AM
Subject: [TechAssist] Re: VS4551 mitsubishi ,no power up when cold: only
thump-thump. still not fixed
> yes.Used spray.
> This I think is several possibilities:
> One, a weak part(probably a cap) is actually /discharging over night/
> being unplugged (rather than coolingdown.)
> Once it has been tried the next morning, it gets charged up and will
> soon work all day.Cooling sprays would be no help here.
> Second possibility is temperature of a borderline part /cooling
> overnight./
> Third: a /hairline crack/ in a trace,solder connection,etc, thru
> /expansion/contraction overnight/ affects it.
> I flex, tap,etc while on and get no reaction. I have freeze sprayed
> while on the caps and some reg ICs to no avail. The real test is always
> overnight unplugged. I was thinking of /leaving it plugged in/ but
> turned off this weekend to test my charge-up/discharge cap theory: Is a
> part discharging, or cooling off.
> Phil
>
> al m wrote:
>
>>Phil did you try to use freeze spray?
>>Al Marquardt
>>ampm@xxxxxxx
>>Al Marquardt Electronic Repair
>>206 W Main
>>Girardville Pa. 17935
>>----- Original Message -----
>>From: "Phil Bader" <tjanphyl@xxxxxxxxxxxxxxx>
>>To: <techassist@xxxxxxxxxxxxx>
>>Sent: Saturday, March 05, 2005 10:54 AM
>>Subject: [TechAssist] VS4551 mitsubishi ,no power up when cold: only
>>thump-thump. still not fixed
>>
>>
>>
>>
>>>ARRRRG! I watched this set an hour last night, unplugged it, went home.
>>>This morning, again, plugged it in cold, pushed power: "Thump-Thump..."
>>>Same crappola.
>>>I immediately unplugged it, removed back, removed two screws holding the
>>>chassis frame in. Plugged it in, powered it up perfectly.Then I flexed,
>>>tapped,etc.No effect. I am still not sure if this is a borderline cap
>>>discharging overnight and cooling(bad ESR) or some bad connection. I'm
>>>stumped. I KNOW the cap i replaced last night was bad (see thread below).
>>>Phil Bader
>>>
>>>
>>>FIX?
>>>I may have fixed the start up problem. I first replaced IC9A1 , an SE130
>>>regulator.
>>>But I then ESRd caps all over. I came across one cap soldered to the
>>>bottom of the board to 5 pin regulator,IC9A2 (looked like soldered to
>>>pins 1,2) It was a 4.7mfd@50V. It was totally open.
>>>I replaced it.
>>>Unit came right up with good picture.. Tomorrow morning will be the test
>>>for the cold start.
>>>Phil Bader
>>>
>>>Phil Bader wrote:
>>>
>>>
>>>
>>>>The fix for the "arcing" vertical distortion was not the yoke
>>>>connection, but many cold solder joints on main board, especially the
>>>>board yoke plugs. Can't believe I missed them all. Resoldered, fixed.
>>>>I came in this morning, and the TV being cold and unplugged all night,
>>>>pushed power and I only heard a once per second "thump-thump-thump"
>>>>noise. We feel this may be one of the PS electrolytics with hi ESR, and
>>>>when cold, does this but if warms up, runs OK.
>>>>Anyone have any specific tech tip on this model for this???
>>>>This will be #3 repair to get this out the door!
>>>>Phil Bader
>>>>
>>>>This played two days OK. Then the vertical distorted like arcing,
>>>>pull-up, lines stretched,bowed etc.
>>>>I did resolder the vert output IC. If I hit the side of the setwhile
>>>>happening it cleared.
>>>>I saw somewhere in a fix email,was to solder the yoke pin.Sounded like
>>>>they meant actually at the yoke (as opposed to on the board) I quote:
>>>>
>>>>"Cure: Found bad solder connection at connector on red yoke. Reason for
>>>>no
>>>>deflection is these connector run in seres to the other two CRT's."
>>>>Anyone care to clarify this?
>>>>Phil Bader
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>--
>>>
>>>Philip Bader
>>>Jan Phyl TV Inc. (estab. 1976)
>>>3420 Recker Hwy. Winter Haven, Fl. 33880
>>>Fax (863) 299-8821
>>>email: tjanphyl@xxxxxxxxxxxxxxx
>>>
>>>
>>>
>>>
>>>--
>>>
>>>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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>>>Version: 7.0.300 / Virus Database: 266.5.5 - Release Date: 3/1/2005
>>>
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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
>
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.300 / Virus Database: 266.5.5 - Release Date: 3/1/2005
>
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