[TechAssist] Re: Panasonic TV CT-3269SCW Chas. AMEDP311 repeatedly blows regu...
- From: Jorge Camboni <geo@xxxxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Tue, 30 Dec 2003 14:22:23 -0600
The 2SD2539 DOES have a damper (and a 50ohm resistor between
emitter and base). The main difference with the 1880 is the higher
beta, you can expect the 1880 work more or less normally, perhaps
somewhat warmer, depending on circuit design and beta spread, in
the worst cases it gets really hot...
So the problem is not there...
Jorge
At 01:34 p.m. 30/12/03 -0500, you wrote:
>Gary,
>
>Info from a similar chassis ABP331.
>The 2SD2539 is a non damper transistor, the 2SD1880 has a built in damper.
>Your regulated B+ should be 130VDC. This B+ passes thru a fusistor pair R808
>and 809, 1 Ohm 1/2 watt. These pass B+ to/thru L803 and to pin 9 of the FBT
>out pin 10 to the horiz out transistor. Horizontal driver Q501 is fed by a
>resistor pair R510, 511 3.6k 3wt.
>
>Let me know if this helps with your chassis layout.
>
>Dominic DiLeo
>Atlantic TV
>Freeport, Maine
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>In a message dated 12/30/03 11:13:08 AM Eastern Standard Time,
>gary@xxxxxxxxxxx writes:
>
> > I have received the new regulator IC and HOT from Panasonic. I replaced
> > a number of capacitors, D825 and it's filter cap, and I checked the
> > flyback out of circuit with my HR Diemen flyback tester and it shows a
> > good collector waveform and 30kv readout. I installed the new reg. but
> > decided to use a 2SD1880 to test the set with until I know it is ok to
> > install the (expensive) OEM HOT 2SD2539. I fired it up on 95V ac on the
> > variac. The set does not start up. I get 148V dc on cathode of D825 and
> > I get 31V dc on the B+ pin on the flyback.
> >
> > I don't have a schematic to trace the reason for the B+ voltage drop
> > between the source and the flyback. I am only assuming that the cathode
> > of D825 is the (130V?) B+ source for the flyback. Tried tracing it on
> > the circuit board but got lost.
> >
> >
> > Any help appreciated, especially a partial schematic for this this
> > chassis or similar chassis which includes
> > an STR58041A regulator.
> >
> >
> >
> >
> > Gary McCartney
> >
> > McCartney Electronics
> > Guelph Ontario Canada
> > Est. 1984
> > email: gary (at) number63.ca
> >
> >
> >
> >
> >
> >
> > My original message:
> >
> >
> > I have worked on this Panasonic 32" TV model CT-3269SCW Chassis AMEDP311
> > about 4 times in the last year or so. One time the HOT and regulator
> > (STR58041A) were blown and I replaced with OEM Panasonic parts along
> > with a few supporting parts in the regulator circuit which I don't
> > remember at the moment. Another time the flyback was shorted. About a
> > month ago, the regulator was shorted so again I replaced with OEM part
> > and today the customer called and said he is bringing the set back in
> > first thing Monday morning, hoping to have it repaired for Christmas. He
> > heard a POP and the set went dead.
> >
> > It seems there must be something I am missing when I'm replacing HOT's
> > and regulators on this set. Is there a service bulletin or a known list
> > of components which need attention while serving? I have soldered the
> > hor. driver transformer. I don't work on many Panasonics but the ones I
> > do usually are dogs.
> >
> > I am wanting to be able to order parts by noon on Monday so I can
> > hopfully get this set shipped before I close down for the holidays.
> >
> > Merry Christmas to everyone and thanks for any help.
> > --
> >
>*****************************************************************************
>Lost Password:
>http://www.tech-assist.org and select "Login Problems?".
>Email Archives:
>//www.freelists.org/archives/techassist/
Jorge Camboni, GY Electronics, Richardson, TX
*****************************************************************************
Lost Password:
http://www.tech-assist.org and select "Login Problems?".
Email Archives:
//www.freelists.org/archives/techassist/
Other related posts:
