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Toshiba tv clicks CN30C90

Toshiba Cyclone mod. CN30C90 Chassls 9300. Relay clicks when plugged in. Goes into shutdown when power button is pressed. I went thru the 800 series caps for high ESR. Only found C840 bad. Anyone have any repair tips on this model? Any known problem areas? Thanks Roy

Reply to
Roy and Rosa
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Check for a "pico fuse", small green in colour I think, close to the front of the main board, I think! Rono.

Reply to
Rono

"Roy and Rosa" ha scritto nel messaggio news: snipped-for-privacy@corp.supernews.com...

Have you checked the HOT ?

I.

Reply to
Inty

"...

No blown fuses. Hot is good as well as the flyback. Problem is in the SMPS or associated circuit. When I jump the ac relay which provides power for B+(with HOT removed), T862 clicks like it has a short in the secondary but it only draws about 400 milliamps. But I can not find any shorted diodes. I get 115vdc at C884 and 20vdc at C889 which doesnt seem too high. Anyone know what voltages I should see at the hybrid regulator STRS6501? Anyone have a scan of the service manual or schematic? Thanks Roy

Reply to
Roy and Rosa

If you have 115v on the secondary, you do not have a short in the secondary of the smps. It is probably clicking because the smps is in effectively an unloaded condition as the horizontal is not running.

Start at square one with the basics and work your way down from there:

  1. Standby voltage to system control and the 60Hz clock pulse from ac line.
  2. Turn on signal from system control, possibly both to relay and on I2C data bus.
  3. Horizontal run Vcc
  4. Horizontal drive pulses out of jungle ic
  5. Horizontal drive to the base of HOT
  6. Main B+ to the collector of HOT
  7. Then troubleshoot the reason for the shutdown, lower the B+ to the flyback system with a resistor or light bulb and scope the flyback waveforms.
  8. Then work back to the must have feedback signals, x-ray protect in line, h-sync return, v-sync return, I2C all ok return from misc ics, etc.
Reply to
dkuhajda

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