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Re: Philips TV 17 TX 250 A

Geschreven door Henk van den Broek op 07. Jul 2006 16:53:46:

In reactie op: Re: Philips TV 17 TX 250 A geschreven door Johan van der Levin op 07. Jul 2006 14:42:55:

Hello Johan,

if the picture does not seems to show any disturbance during the ticks, I think the LF-output stage is oscillating at a low frequency. You can make this visible if you own an oscilloscope.

When you change volume and tone control settings, does this change the frequence of the clicking sound?

Did you measure the DC-voltages in the LF-stage and are they about the same as on the schematic?

Have you already tried exchanging B3 and/or B4? if you have no other PCL85, you can (for test-purpose) exchange B4 with B18 teporarely.

Furthermore, the next capacitors can be suspecious: C45, C44, C46 and, in the supply part, C14, C11/C12,C17.

Also check all the resistors in the LF-stage and the supply part for this stage.

Henk




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