Look at D1301 - a thyristor on the LPF Board. If this has failed shorted it'll cause the Protector circuit to open the associated relay and cause the Blanker circuit to flash the red meter lamp. It'll also shut down the exciter and amplifier sections of the transmit signal path. Also examine the relay - does it open as soon as power is applied to the rig? If not, could be as simple as a faulty (dirty) relay. No current through it means the SN7400 on the RF Board won't receive voltage and will block the transmitter from operating. Ditto the Blanker circuit.?
73 - Fred, N8YX?
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-------- Original message --------
From: sdandrus@...
Date: 5/4/20 9:25 PM (GMT-05:00)
Subject: Re: [yaesuft301d] Ft-301ad blinking s-meter no transmit
Thanks for the reply. The in and out are jumpered together so the signal is going out the antenna jack. Just in case though I tried what you suggested and connected the dummy load to the out BNC and have the same results. To clarify, the S meter is always blinking, from the time it is powered up. I do not have to try to transmit for it to be blinking, its always in this state. If I do try to transmit, there is a relay that switches over but the radio puts out zero watts. I'm thinking it might be a problem with PB-1445, the protection circuit relay or something like that but am hoping someone might know a trick that will help me avoid testing every component.
