Fender Frontman 212R

[kebaborg]

Hi
sorry for my english, i'm from Russia
i have problem with my 212R
My amp start crackling after about 1 hour of using, also R144 and R145 are very hot
i replaced all polar capacitors and potetiometres

[J M Fahey]

Hi
sorry for my english, i'm from Russia

Welcome

R144 and R145 are very hot

they DO work hot, thatīs why they fit 5W resistors there.

i replaced all polar capacitors and potetiometres

You should not have done that.
Nothing suggested they are bad; at most you should have *cleaned* them first with some potentiometer/switch/contact cleaner spray.
You must first find the problem, then try to solve it.

i have problem with my 212R
My amp start crackling after about 1 hour of using,

Ok, then first try to find which area can crackling come from.
* does any control have any effect on crackle?
* does it happen on both channels?
* if you plug a spare guitar cable in the Loop In/Return (keep the other end unplugged but touching nothing) , does crackling stop? It might hum now but that is not to worry at this moment.
* if you hit amplifier top hard with your closed fist, does crackle stop/increase/"crackle" ... this might show some loose part or connection inside.

Now itīs already done but every part you replaced with no reason *increases* the possibilities of poor new contacts, without solving the original one .

Ok, do those tests and report results.

[kebaborg]

Ok, then first try to find which area can crackling come from.
* does any control have any effect on crackle?

no

does it happen on both channels?

yes

if you plug a spare guitar cable in the Loop In/Return (keep the other end unplugged but touching nothing) , does crackling stop? It might hum now but that is not to worry at this moment.

no

if you hit amplifier top hard with your closed fist, does crackle stop/increase/"crackle" ... this might show some loose part or connection inside.

no

[The Dude]

If it starts after warmup, I'd try a can of freeze spray and see if you can narrow it down with that.