There are dangers in every scenario, this one is not unique.
We discovered 3 (three) things...
Cracked cap,
Bias not working right
and bad output cap.
Out of those three...
Whether works been done to it or not, [USER=46485]@Adamf[/USER] he admirably - took to the task of attempting to fix his radio.
- What you may have got confused with, is me asking if he's done MOSFET before?
- IF that is the case - my intent was to warn the OP about things that may not look right.
- There are two types of parts that can be used in THAT SAME BOARD - that's our curse.
When previous work has been done to it or not - I work alongside people that share a passion for radio - up to and including keeping this market-hobby-effort alive by trying to repair radios that would otherwise be filling up landfills.
You are seeing some of the success and failures, of Forums versus owning a shop and knowing exactly the condition of the problem and it's solutions - at hand - by being there working on the problem directly.
People make a living off of that.
I also understand that you can get in over your head.
You can also maintain a radio by just repairing that which is broken and the radio will recover.
There are people out there that make fun of our hobby and even how we act out there...
Some people though, don't take it well.
It's not that simple.
In this case, my failures are simple, MOSFET to Bipolar or if the radio quit, (being blunt) directly - no matter what - [USER=46485]@Adamf[/USER] took to the challenge of repairing his own equipment. I'm trying to pick up where he's at and the direction we went, - accelerated pretty fast.
Now, to review, if he only replaced the cap - it may or may not have worked.
The output cap failed, but for that failure can be the Final and or Driver (both really) right along with it.
Bias was low or inadequate - could it have caused the Final to fail - yes, because I've seen radios that seem normal and brand new - fail unexpectedly - power surges onto long winded SSB nets - people don't know what's going on with the radio until it doesn't work anymore.
So what caused it?
I have theories and even posted some possible solutions - but that doesn't fix the radio that's broken
To apply the suggestions for others to use, just might let those other radios last longer - but we still have a radio that whether it's been worked on before or not, there is a user out there determined to fix that which is broken.
So if you're saying He didn't have any work done to it, it didn't matter to me.
- - I'm letting him see My Approach in the repair,
- - MOSFET or Bipolar, there may be a lot of work to do to restore everything back in.,
- - I'm also advising - not trying to have him recreate the problem ...
- I only asked if he had work done to it - not the "he did the work to it" No!
- - did some one work on his radio before this?
- - and after some time using it - it doesn't work...
- The above statements have to be taken seriously, for if it is not followed, replacing parts will only allow the radio to be used for short times before the problem occurs again.
- IF it's due to a poorly done mod, you correct the mod first to make it work right then the radio can survive.
- now you know what has been done,
- replace the output cap,
- fix the broken one,
- keep the final and driver parts from the OEM (not the 520N)
Now...- does it fix the Bias?
Does the Radio start working right? Maybe maybe not.
- - I am fixing, working - helping someone - taking them at their word - trying to restore something they cherish enough to keep and fix themselves - they already went too far.
I'm not questioning the OP.
IF they want my help, they let me come alongside and work with them - in many ways the effort of communication goes beyond the simple and into pretty complex interactions not normally seen in Twitter or other Social media outlets.
That is the beauty (or curse) of the Forums approach.
Way too easy for someone to come along and take a stalled car and turn it into a twisted wreck.
I'm posting this as a reminder to myself...
Don't take myself too seriously...
