RCI-2970N2 won't unkey

[cbkidd1]

Hi Chris,
There are two holes one on each side of the pushbutton board. And two more on the CPU board, With two plastic spacers in between both boards. Between the two boards is a long plastic board looks like it is used to separate the two boards from touching each other. From what I can tell the pushbutton board has the 6 pins coming out of the back on each side and going thew the white connectors on the CPU board. So it looks like I just need to be very careful and separate the two boards from each other and reconnect the pushbutton board to the new CPU board? Here are a few pictures not sure if this will help or not. Chris, You don't know how much help you have given me thew the years and have also taught me a few things along the way. I forgot to mention help me save a lot of money I did not have to spend. For all of this, I am very grateful. Thank you once again, 73, I received a Massage from Greg, Here is what he had to say,

Yes, you can just use the old one. It just plugs into the processor. Just be careful to get it pluged in good. Greg

 

[NZ8N]

The button board looks like the same one as the original non-DX 2950 or 70 radios I have worked on in the past, and the button board does separate from the CPU board.

 

[cbkidd1]

Thank's NZ8N, Think I am going to be very careful and try and remove it. I just don't understand why they would not put both the boards together and sell as one?

 

[cbkidd1]

I had no trouble removing and installing the pushbutton board onto the main CPU board. Radio seems to be working just fine. I want to find out were the Hi and Low dead key should be set? I also took notice that someone had unsoldered what I think is a resistor that is to the left of j8 8 volts. And to the right of a diode. Could anyone tell me the purpose of this resistor? I had found out that the gentlemen who org bought the radio from Bells CB in Florida. His CB handle is Screwdriver. Please tell me this guy knows how to align a radio? 73,

 

[cbkidd1]

I spoke too soon. It appears I have received but when I go to transmit I have no output power at all. The transmit light on the radio comes on but there is no wattage showing on my meter? Could the resistor or transistor? That I found with the one leg unsoldered and I took off the other two legs to remove it be causing me not to be able to transmit? Here is a picture of where the part goes on the board.

 

[999]

That 3 pad is for a diode (D65). I suspect that is your issue.

 

[cbkidd1]

Hi, 999 It's right next to the diode. It has three prongs two on one side and one on the other. Before I took it off the one prong was lifted up the other two were soldered in place. I mistook it for a modulation limiter that someone had just disabled. So I removed it from the board. Not knowing that it would affect my transmit power. At the same time, I was waiting for a replacement CPU board. After putting the new CPU board in I thought the radio was working fine until I went to key up and seen that I had no output power. So you think that's what is causing me to have no power? It's the only other thing I did on the radio. Thank you for your help.

 

[999]

That is also is a diode. And if the radio worked before, and not now, I would start there.

 

[999]

This is the area highlighted in red with the missing diode highlighted in yellow.
It's upside down so that the orientation is the same as your picture.

 

[cbkidd1]

That's a great help for sure. So I guess that is not a modulation limiter after all. The prongs are cut so short on the diode I don't think I can reconnect them. Would you happen to know where I might be able to buy another D65 diode? Or is there a way that I could use a jumper and connect two of the three pads as a workaround until I can find a replacement part? I have looked everywhere on the net for a service manual for the EPT-695015BR board or another radio that uses the same board but have had no luck at all finding anything. I really appreciate you taking the time to try and help me with repairing the radio. 73, ed,

 

[999]

Part number MA28T
This is the data sheet on the diode.
https://www.datasheets360.com/pdf/-4141293513509449935

 

[cbkidd1]

Do you happen to know where I would get the part from? Thank's

 

[999]

No

 

[cbkidd1]

Why would RCI Ranger still make 2970n2 smt transceivers knowing you can not find the parts for them if something should go wrong I for one would have not ever bought one knowing that parts were not available to fix them. I received an Email back from Galaxy telling me to call John. So I am going to call today and more than likely be told the part is no longer available. Will let you know. 73,

 

[nomadradio]

MA28T from ChinaBay:
https://www.ebay.com/itm/5PCS-X-MA2...149801?hash=item4d6c38e529:g:On8AAOSwXOhaZRDV

At least that part can be found, or so it seems.

SMT is the wave of the present. It exists to make it easier for machines to assemble a circuit board. Makes stuff smaller, as well. A simple, dumb flip phone would be the size and weight of a paving brick if you built it from the old-style parts that used lead wires through holes in the circuit boards.

Being competitive in any manufacturing business is about beating the other guys on cost. Labor is the biggest single expense in any manufacturing business. Assembling SMT circuitry with robot equipment saves an immense amount of labor cost. The parts are cheaper, as well as smaller.

A manufacturer couldn't care less about how much trouble his product will be to repair or maintain. Any gadget that still works after the warranty is up slows down replacement sales.

Bigger rule that applies to any manufactured product is that any change you make to the design that simplifies putting it together, will also make taking it apart later more complicated.

Learned this under the dashboard of Detroit-made cars 45 years ago. Asked the boss just how I'm supposed to loosen a 3/4-inch long screw that has a quarter inch of clearance above the screw head. Hire a half-inch tall guy to climb in there and take it loose? The boss explained that the dashboard is built separately from the car, and then dropped in as a unit on the main assembly line. I was never supposed to take loose the duct section in question once the car was built. He said ya just hafta improvise.

Some things never change.

73