[TenTec] Problem with Omni VI

[Ron]

On 4/6/2013 8:36 AM, Jaime Gomez wrote:
> I have an Omni VI Plus Model 564 that suddenly stopped receiving and
> transmitting eventhough the display shows the frequency and changes with
> the dial.
> Troubleshooting the unit I found that the 5.0 -5.5 MHz output (No. 85) from
> the 5.5 MHz PLL board does not change with the dial, it is locked in 5.8
> MHz and the voltage in pins 3 and 4 of the PLL IC (IC6 - MC145156P2) des
> not change with the dial as it is supposed to do, so the voltage
> controlling the VCO diodes V9 and V10 is fixed.
> My obvious suspect was IC6. I was lucky and found 2 from Hong Kong.
> Yesterday I received them and today I replaced IC6, but to my surprise the
> problem continues the same.
> It is almost impossible to send the equipment back to Ten Tec for repair
> from my country. Any hint as where should I continue looking at?
>
> Thank you, appreciate any help,
>
> 73, Jim, HK1N
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Obtain an in-circuit capacitance checker, and check for bad capacitors 
anywhere on the board. Caps fail more often than any other component, 
and they are best checked with a device such as the ESP meter available 
here:

http://www.ebay.com/itm/Capacitor-Capacitance-Cap-ESR-Meter-Tester-Combo-DMM-MESR-100-JY6013-/390436299020#vi-content

Otherwise, your problem will be an active device in the tuning circuit.