[TechAssist] Re: Magnvox, 27TP83, ch. 27v505, no video{FIXED}
- From: "D Thunhurst" <dthunhurst@xxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Mon, 13 Jan 2003 17:27:17 -0700
This dog is finally going home.
Sorry for the delay on this fix as it takes forever to get parts nowadays.
Originally it came in with sound and no vert. deflection, in on both sides
about 3 inches and would shut down after a few seconds.
Replaced R464 (4.7 ohm) off of IC401 (9v reg) as well as the 9v regulator
and IC550 (LA7838), vertical output. This restored full deflection giving
sound and just a raster with retrace lines. Thanks to Bob Waterman for the
help, the final cure was IC200 (TDA8389), jungle chip and IC51 (TDA6103Q),
RGB driver.
What ever happened to the "easy fix" sets? :-)
Again, thanks for the help.
Daryl
Daryl's TV
3310 Dyer St.
El Paso, TX 79930
915-565-9184
915-564-1024 Fax
http://dynacomp.freeyellow.com
-----Original Message-----
From: Gemini Computer & TV <geminitv@xxxxxxxxxxxxxxxx>
To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
Date: Thursday, December 26, 2002 6:05 PM
Subject: [TechAssist] Re: Magnvox, 27TP83, ch. 27v505, no video
>
>Pins 7, 8, and 9 should be about 143 volts or so but since you have no
video
>input, it makes sense. Looks like you do probably have a bad signal
>processing IC (IC200). The newest part number is 483520988503 and is in
>stock at Tritronics for under $20.00
>
>Bob Waterman, CET® #RI-28
>Master Technician License #9109
>Service Manager
>Gemini Computer, TV, & Security Alarms
>(508)695-7302
>(508)695-7769 FAX
>geminitv@xxxxxxxxxxxxxxxx
>geminitv@xxxxxxx
>
>----- Original Message -----
>From: "D Thunhurst" <dthunhurst@xxxxxxx>
>To: <techassist@xxxxxxxxxxxxx>
>Sent: Thursday, December 26, 2002 1:16 PM
>Subject: [TechAssist] Re: Magnvox, 27TP83, ch. 27v505, no video
>
>
>>
>> Bob,
>> As requested, the voltages in IC 51 are as follows:
>> p1=1.35v
>> p2=1.34v
>> p3=1.34v
>> p4=0v
>> p5=1.34v
>> p6=198.7v
>> p7=49.2v
>> p8=57.6v
>> p9=43.1v
>> I don't show any video present whatsoever on any of the pins of IC200.
>> Now I seem to be loosing a little ground on it. It is now giving a
raster
>> that progressively gets brighter and is going into shutdown. I rechecked
>> the resistors on the crt board and found none bad.
>> Daryl
>> Daryl's TV
>> 3310 Dyer St.
>> El Paso, TX 79930
>> 915-565-9184
>> 915-564-1024 Fax
>> http://dynacomp.freeyellow.com
>> -----Original Message-----
>> From: Gemini Computer & TV <geminitv@xxxxxxxxxxxxxxxx>
>> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
>> Date: Thursday, December 26, 2002 8:07 AM
>> Subject: [TechAssist] Re: Magnvox, 27TP83, ch. 27v505, no video
>>
>>
>> >
>> >First,
>> >Give us the voltage readings on all 9 pins of IC51 on the CRT board.
Pins
>> >1,2, and 3 are the R,G, and B inputs respectively (pins 7,8, and 9 are
>the
>> >outputs). Also scope the inputs to see if you have video coming in. If
>not
>> >then the video comes from IC200 (pins 21, 20, and 19 are R,G,B
>> >respectively). This should get you started.
>> >
>> >Bob Waterman, CET® #RI-28
>> >Master Technician License #9109
>> >Service Manager
>> >Gemini Computer, TV, & Security Alarms
>> >(508)695-7302
>> >(508)695-7769 FAX
>> >geminitv@xxxxxxxxxxxxxxxx
>> >geminitv@xxxxxxx
>> >
>> >----- Original Message -----
>> >From: "D Thunhurst" <dthunhurst@xxxxxxx>
>> >To: "TechAssist" <TechAssist@xxxxxxxxxxxxx>
>> >Sent: Thursday, December 26, 2002 9:05 AM
>> >Subject: [TechAssist] Magnvox, 27TP83, ch. 27v505, no video
>> >
>> >
>> >>
>> >> Good morning.
>> >> I hope everyone had a merry Christmas.
>> >> I am still having some problems with this set. Originally it came in
>> with
>> >> sound and no vert. deflection, in on both sides about 3 inches and
>would
>> >> shut down after a few seconds.
>> >> I replaced R464 (went high in value), IC401 (9 volt reg), and IC550
>> (vert.
>> >> output). Now, I still have sound, full deflection both vertically and
>> >> horizontally, bright raster with full retrace lines and no video. I
>have
>> >> the 200 volts to the crt board and all of the resistors check ok on
>that
>> >> board. I could use a little advice on this one as I don't have the
>> >> schematic and Sams doesn't list anything one it. Tritronics list a
>> manual
>> >> for it but at $60 plus shipping is out of the question. I am leaning
>> >> towards jungle chip but not sure as this is a guess.
>> >> Thanks,
>> >> Daryl
>> >> Daryl's TV
>> >> 3310 Dyer St.
>> >> El Paso, TX 79930
>> >> 915-565-9184
>> >> 915-564-1024 Fax
>> >> http://dynacomp.freeyellow.com
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