[TechAssist] [Fwd: Sony PTV KPR-53EX35 (Aug.91) intermitt. shut down then black screen.fix]
- From: Phil Bader <philbad@xxxxxxxxxx>
- To: "techassist@xxxxxxxxxxxxx" <techassist@xxxxxxxxxxxxx>
- Date: Thu, 18 Oct 2001 10:34:17 -0400
-------- Original Message --------
Subject: Sony PTV KPR-53EX35 (Aug.91) intermitt. shut down then black
screen.fix
Date: Thu, 18 Oct 2001 10:31:07 -0400
From: Phil Bader <philbad@xxxxxxxxxx>
Organization: Jan Phyl TV Inc. Winter Haven, Fl. Estab. 1976
To: "CONSUMERELREPAIR-L@xxxxxxxxxxxxxxxxxxxx"
<CONSUMERELREPAIR-L@xxxxxxxxxxxxxxxxxxxx>
Customer said it would run all day,or hours,then shut down.Let cool and
ran another hour or so.Finally,no pix at all and no illumination on
screen.We noticed when on it had high voltage to CRT anodes,had filiment
glow in CRT necks,and the voltages from "G" power board were
there.Scoping the vert. output at plug D16 showed about 2 VPP waveform,
where there was supposed to be 100 VPP. So, we had HV with no
deflection.On a hunch, we ordered and replaced the "jungle chip" IC201
(CXA1012AS, # 875203171 @ $23.36 cost). Now we could advance the G2
controls and see illumination on the faces of the R,G,B CRTs (looking
down on them from inside). I noticed in the green CRT the word
"video".Now, changing input from "video" to "tuner" signal input
brought snow on all CRTs.Moved the unit,it shut down again.Further
inspection revealed the "G" power board had bad solder on some
components especially the two "dual-power diodes (3-legged) mounted on
heat sinks-very bad solder. Resoldering the "G" board cured the
intermittant condition that probably stressed and blew the jungle chip
IC201. Now, no sound most stations; Cause: was in SAP mode.Must have
remote to select.Now all is OK. So: Cure was replace IC201 and resolder
G board.
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