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Re[9]: Convergence problems on AV-48WP30
Eric Posted Dec 06, 2006, in response to:Paul
Did you have a power surge? Any number of things can cause a dead set. You know that the AV-48WP30 is prone to convergence problems. Could be that either of the Convergence Out IC's shorted and caused problems in the power supply.
Read the following, it might help.
Replaced
Cp943 Open, Icp-N20-Y
Q953 Short, 2sc3311a/Qr/-T
D918 Short, Mtzj5.1b-T2
Ic911 Short, Str-F6629b/F7
Ic921 On Spec, Se140n
Pc921 On Spec, Pc123f2
D958 Leaky, Mtzj6.8c-T2
More Info:
Original Symptom Was When Power Pressed, The Power Supply Relay Clicked On And The Blue Power Led Came On And Stayed On Steady, But No Other Response. After Awhile The Set Would Shutoff (Not Shutdown), By Itself. Or It Could Be Turned Off If The Power Button Was Held Down Until The Led Went Off, 10 To 20 Seconds Later. The B+ Relay Never Clicked On Or Off.
Originally Found And Replaced Open Cp943, Q953, D918, Ic911, And Ic921 (Pc921 On B.O.). The Symptom Changed To Turn On With Power Button, Power Supply Relay Clicked On And The Blue Led Came On With The Power Supply Ticking, And Within 10 To 20 Seconds The Set Went Into Shutdown With The Blue Led Blinking On 1 Second Off 1 Second Repeat, Which Troubleshooting Indicates Is A B1 Over-Current Protect. Note That B1 Is How It Is Shown In
The Manual. I Do Not Know If It Is A Typo And Should Say B+, Or If B1 Is A Designation Jvc Uses. Also Note That The Blue Led Was Never Really Off, It Blinked Bright/Dim, Not On/Off. The B+ Relay Again Did Not Click On Or Off, Only The Power Relay.
Pc921 Finally Came In And Still Had Same Symptom, Which Is When I Replaced D958. It Tested Good But Must Be Breaking Down In Circuit. Clue Was Voltages On Q953 (And Elsewhere) Were Jumping Up And Down While Set Was Ticking.
Good Luck,
Eric
Reply
2 comments
found this stuff relating to the thumping heartbeat power problem but will be a while before I can try any of it:
No. The CRT driver ICs are prone to shorting and cause this symptom (I just had one with those very symptoms and the green CRT driver IC was shorted). Disconnecting the CRT board does not clear the short on the board. Often then is a small burn mark on the CRT board under the affected IC (but not always). The IC should be a TDA6111Q. Be sure to note the proper position
of the IC as it should face with the letters TOWARD the heat sink!!!!
Check the CRT driver ICs on each of the CRT boards.
I would disconnect each crt board and hv lead one at a time and try. Have seen several bad tubes on that model. The only other problem I have seen on that set is bad convergence amps, however that doesn't cause shutdown.
when turned on Video drive IC (IC1101) on the red CRT module
shorted. It looked like bad solder on the B+ was the cause
Frequently Used Top Five Repair Parts by symptom code
MODEL NUMBER : AV48WP30 - TV
SYMPTOM CODE : DEAD
TOP FIVE PARTS :
2SC5552-RL
2SC5904-RL
QQH0113-002
STR-F6629B/F7
STK392-110
Above from JVC Web site, also I have seen shorted video drive IC's on the crt boards short and cause this symptom. Try unplugging the 200 volt source to the crt boards and see it the set powers up and stays on. There is a B+ relay which supplies 130 Volts to the horizontal output circuit. Is this relay energizing? I takes about five seconds after the power is turned on for it to energize. If a short is detected on the 130 volt line the blue power lamp on the front will do what you describe and the relay will pulse on and off.
symptom:
Non-functional Digital Input
Solution:
1. Power off the unit
2. Disconnect the digital input if it is connected
3. Remove the rear cover
4. On the digital input module, using a shorting pin (PC type) or a
jumper, short Pin 1 and Pin 2 of the
SB connector
5. Power on the unit
6. Unplug the unit and remove the shorting pin or the jumper
7. Re-attach the unit’s rear cover
8. Power on the unit, and input the digital source
Reply
I'm having convergence issues as well, I have a green streak in top left corner that I can't get to go away probably because the green is unadjustable. So I guess something has to be replaced. I tried to adjust convergence but the green streak remains, any advice.?
Comment 1, Last comment
by Eric Dec 28, 2006
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