RCI 2995DX-CF no output...

[Hawkeye351]

Got a 2995DX-CF with no output, no meter movement at all in any mode on external or internal meter.
Everything else works great.

Story behind how this happened:

This radio is only about 2 years old. After a year went by and the warranty went out, the original owner asked me to throw an alignment on it, nothing else. I finished it up and got it back to him, he talked on it about every day until a friend of his talked him into buying one of those RCI-29 bases (bad choice). He sold the 2995dx-cf to get the money to buy the RCI-29.

Well, the guy he sold it to is a drunk, know it all, arrogant individual. This guy was caught by the original owner with the cover off and yelled at him about why he's in that radio. He told him there's no sense in him going in that radio. The other guy said he was trying to get more watts out of it (hell, I had it doing about what it supposed to do, 220w PEP, 115w peak and 40w average with no mods and all limiters intact). The original owner told him Hawkeye (me, lol) had already aligned that radio and you can't get any more out of it.

Well, the drunk decided later to hook a 4-tube elkin to it. 220w going into a 4-tube elkin. What do you think happened? Yep, the elkin blew up as did this 2995dx-cf. Catastrophic failure due to negligence. Another victim of one of the decades old Golden Screwdriver jockies...

Replaced:
All Mosfets, even the ones on the dx-cf amp board.
Passthrough regulator.
AF regulator.
(Did the repair of a 2995dx-cf with no transmit fix as posted on YouTube).

Results:
Driver bias will not adjust (stays on 0.00)
Final bias adjusts fine up to 50ma (3.76v).
The relay on the amp board switches when the PTT is keyed.
No output whatsoever on any mode.

Replaced driver bias VR, still nothing. No ma and no output whatsoever but final bias is set fine and amp relay switches when keying the PTT.

Any ideas?

Damn shame, practically brand new radio.

 

[TM86]

Any ideas?

Find drunk and beat him with the dead radio?

 

[Hawkeye351]

Trust me, everyone around here is fed up with him. Constantly starts arguments with another local drunk, but then turns into a victim when people snap on him. This guy goes from channel to channel looking for an argument.

He thinks everyone around here is mad at the other local drunk, but we're not because he tries to avoid the arguing until he gets poked at once to much.

And he's got a lot of others in skipland hating on the other drunk, just for defending himself when the arrogant drunk pokes at him too much.

Like I always say, you keep poking that bear, and he's eventually gonna retaliate.

 

[nomadradio]

Zero bias current on the driver would send me to the 'scope to see if it has any DC voltage on the drain tab.

For that matter, can you hear any transmit signal on a monitor radio set to the same channel? Would be an important starting point.

73

 

[Hawkeye351]

Yes, we can hear audio transmitting to another radio in the same room.

Odd thing is, the driver bias adjustment will adjust for voltage fine, but will stay at 0 when checking current draw. I figured the driver VR had blown enough to still carry voltage but not current, that's why I replaced the driver VR.

Haven't checked drain voltage, will do that and get back with you shortly though.

How would you recommend checking the drain on it? Do I leave mirror board in place and just check the voltage on the drain pin as I would check the gate voltage?

 

[nomadradio]

Do I leave mirror board in place and just check the voltage on the drain pin

Just poke your probe to the exposed metal of the mounting tab. Safer than probing the center pin on the pcb.

73

 

[Hawkeye351]

Bad news!!!

This practically brand new radio never had a chance when it left the original owners hands.

I was helping this local get it back together the past few weeks. He does great solder work, listens very well and has fixed several radios of his own, sometimes with my help and sometimes on his own.

All we had left was figuring out the driver bias issue, that's all. We had already went through all the other parts and fixes. Just this one last minor issue is all we had left to figure out.

Well, I got back with him to ask him to do the voltage test on the tab of the driver. He responded back with "it's time to take a hammer to it". I responded back and said "noooo, don't do that, I'll take a look at it", he responded back with "it's already done my man". He later told me he took the faceplate off so he could at least sell the faceplate on eBay and get some of his money back, and that he kept the amp board out of it but the rest got the hammer.

Damn shame, practically brand new radio straight from the factory about 3 years ago is now trash, all because of one last minor issue.

Sad...