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ranger 2950
Posted: Friday 22nd Aug 2008, 10:06
by tireman247
here i have a ranger 2950 bord#ept295013z .the problem is that i have very low rx and low tx (2w swing down to 1w) i tried to adjust tx and rx but all i get is squeal in the speaker and some time it squeal so bad that the tx come on by itself at 2w carrier and when i key on the mic i get 10w ?can anyone help me troubleshoot the problem ? i do have a scrap 2950 for parts if needed and i have the service manual from cbtircks but need to know were to start. and if this help i have good audio in PA mode.
Posted: Friday 22nd Aug 2008, 13:38
by woody
replace diode (D79) & diode (D80)and see if that fixes your problem.the part # is 1N4148.this is a switching diode.tell me if this fixes your problem
Posted: Saturday 23rd Aug 2008, 11:37
by tireman247
ok will do when i find them.
Posted: Saturday 23rd Aug 2008, 17:08
by woody
if you have the part side of the radio and the front of the radio faceing you D79 is towards the front of the radio on the right right across from the board mounting screw.It looks like it is to the right of a plug.D80 is below the same plug.If you have any circuit cooling spray, cool the diodes and see if the radio starts to work.This is one way I have found the fix.
Posted: Tuesday 26th Aug 2008, 12:24
by tireman247
just finish replacing d79 and d80 turn on the radio and receive was nice and loud for about 2 min and then went back down same as before,tx did not change still at 2w
so what to do next???
Posted: Tuesday 26th Aug 2008, 14:11
by tireman247
one another thing that i noticed is IC4 T7805CT gets really hot (can't touch it too hot) is that normal to get this hot?
Posted: Thursday 28th Aug 2008, 17:56
by woody
IC 4 is a voltage regulator.yes it is goiing to get a little hot.I would get a can of circuit coolant and cool down the board(do a small portion at a time to see if this is a thermal problem that you are having).once you have found the area that the radio sarts working you will have to spay each part sepretley.I found the best way to do this is to get a straw and put the straw over the part and cool it down.This way the part next to what you are cooling down is not cooling down as well.
Posted: Monday 22nd Sep 2008, 4:12
by tireman247
got the radio fix Q38 was bad so replacing that fix the RX/TX and also replace driver and finals and now have full output power.