[TechAssist] Re: VS4551 mitsubishi ,no power up when cold: only thump-thump. still not fixed
- From: Phil Bader <tjanphyl@xxxxxxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Tue, 08 Mar 2005 09:05:26 -0500
I reassembled the set and lowered it to the floor yesterday. After
being unplugged all night, I plugged it in, powered it up this morning
and came right up OK. No "Thump".Unless I'm crazey, I think removing
that ferrite bead from R9A21 may have fixed it.
A few more days will tell. This has been my month for wierd
intermittants.Stuff you can't push out the darn door.
Phil Bader
Phil Bader wrote:
>I removed the ferrite bead on resistor R9A21 lead per your service tip.
>It said to try this FIRST before doing the other 4 procedures.
>I did Saturday, and this Monday morning I plugged it in, waited 30
>seconds, powered it on and it worked. BUT... It's still on my lift with
>back removed. In case there is an issue that's aggrevated by flexing the
>chassis, I will replace back and slide it off the lift to floor, wait a
>day and try again to be sure. Thanks,
>Phil
>
>Jim Myers wrote:
>
>
>
>>Sent a PDF to your email Phil, sounds like the fix you need.
>>
>>
>>********************************
>>Since 1972 *
>>Jim Myers *
>>Telrad Electronics *
>>Fort Wayne Indiana *
>>********************************
>>
>>
>>Phil Bader wrote:
>>
>>
>>
>>
>>>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
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
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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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