No power

[IK2VOV]

Hello all,
i bought from Sunny the high bands version, the main board is the 1.0, i bought it last year.
I assembled it and it was working, but the power in some bands were over 8/9 watts. I decided to make the corrections on the IF board as Manuel explains, but i probably burned something and the power out was 0. I ordered the mosfet and till yesterday i left everything in a box, this morning i changed the mosfet but i still have 0 watts on every band, but the mosfet is new and good.
I don't know what can be burned else then the mosfet, I hope someone can give me some advise to solve.
I'm sorry for my bad English language.

Best 73's de IK2VOV Gilberto.

[KE0QQQ]

Your English is great ! Better than I can do

I fear you may have 'popped' your finals. The BS170 have a real chance of failing. My first lasted for a couple contacts. I went thru plenty of pops

Do you get any output at all? The circuit that drives the finals can do .03 or so on the display. Makes a good Whisper unit at that point

I learned to install a zener diode, I see Miss Sissy had a neat way to do it. I did not pop anything after I started doing this,, well one,, I managed to make 2 contacts on 15m with my 17m dipole up before they failed.. it was over 5:1 .. darn tiny display.

Search zener and the truth shall set you free.

[IK2VOV]

Thank you for your reply KB0QQQ, the high band board don’t use the BS170 finals but a MOSFET FDT86256, this was burned. I was looking at the schematic of the RF board, there are two diodes (D1 and D2) I haven’t checked them, I will do it tomorrow.
The power out with the MOSFET broken was 0.1W into the dummy load, haven’t checked on the display of the radio, with the new and good MOSFET have the same readings, 0.1W.

Thanks and 73’s.

[IK2VOV]

The two diodes seems to be good, I don’t know what to check else.
Someone have any idea?

Thanks and 73’s