Yaesu Ft-101e drive issue

[WA4JK]

This is kicking my behind. I use the Yaesu Ft101E as a driver on Y'am.. The issue is I lost the drive. At 100% carrier I only have .040ma above Idle of .60ma.
No smells,no fire no pop. changed driver poob, no change. I can change Bias up to over 200ma which shouldsay no final poob issue.
I have only a hand meter with me at my locayion and I ohmed the crap out of caps and no opens.

Anybody seen this before or have an idea where to look?

[N3DRB The Derb]

check coupling cap between 12by7 driver and finals, known weak spot. The relays RL1 and RL2 go downhill and have to be cleaned or replaced.
I have one with a bad relay and it sometimes does not kick in and I lose output power. I'm still learning the rig myself - but the relays have to be the most likely suspect followed by the cap.

[WA4JK]

My output follows my drive IC goes up output goes up. I cleaned the relay. If the coupling cap was open I would have no drive at all. I wounder if it could have increased instead of opened..? Thanks

[ka3zlr]

Hello,

 On a quick thought I would check the Drive Pot and associated circuits for cleanliness and circuit stability...solder connections etc. First...

[WA4JK]

Drive pot checked good and clean. I'm going to change the coupling cap and screen cap for the driver and see what happens. I bought caps from mouser. Ceramic HV, they don't look like they could hold up... Maybe new small caps are better than older BIG caps.. We'llsee

[N3DRB The Derb]

check yer filter caps on your 300 volt B+ line. I bet one or more of them are bad. I just took out 4 bad actors out of #1. look for radial leads 22uf @ 250 Volts on that plugin board in the back.

[WA4JK]

Will do tonight on the 300 B+, I checked all voltages to the socket and got them just fine, but I will check the Caps anyway. I'm changing the c13 and c123 as well.. we'll see where it leads next. Thanks

[WA4JK]

Here's another question; could a shorted Plate to grid in a final give the same indication of no grid drive. I'm going to see if i can check that by removing the plate cap one at a time and see if that affects the drive with the tube still installed. Maybe it the finals and the usual increase in bias was a false indicator. Man I need my test equipmentfrom home bad.