I just turn on the RCI 2950 and it starts scanning from 26Mhz and don't accept no command from the panel keys. I started downloading service manual and understanding schematics. Searching the net for more info I found this forum and I'm happy cos I search for burned traces and cold joints and now the board it's OK. But the problem still persists: when turned on, the 2950 starts scanning from 26Mhz to 30Mhz. Does anybody have a tip on this subject?
Thank you guys in advance.
Carlos Saraiva
Santo Amaro Island
SouthEast Brazil
RCI 2950 scanning at start
RCI 2950 scanning at start
saraiva57
Re: RCI 2950 scanning at start
Radio Make = Ranger R.O.C.
Radio Model = RCI 2950
PCB number = EPT 295013Z
PLL number = DPT 295040Z
What doesn't work on the radio. 1)AM. 2) Keys from the front of the radio 3) Almost burnt R6 on CPU DPT 295040Z ( I want to change the lamps for Hi-power leds, decreasing the power drain of the actual lamps)
What does work on the radio. 1) LSB, USB, FM. 2) transmit and receive very good sound. Squelch, Volume, bands swich
What you have tried so far.
Radio Model = RCI 2950
PCB number = EPT 295013Z
PLL number = DPT 295040Z
What doesn't work on the radio. 1)AM. 2) Keys from the front of the radio 3) Almost burnt R6 on CPU DPT 295040Z ( I want to change the lamps for Hi-power leds, decreasing the power drain of the actual lamps)
What does work on the radio. 1) LSB, USB, FM. 2) transmit and receive very good sound. Squelch, Volume, bands swich
What you have tried so far.
saraiva57 wrote:I just turn on the RCI 2950 and it starts scanning from 26Mhz and don't accept no command from the panel keys. I started downloading service manual and understanding schematics. Searching the net for more info I found this forum and I'm happy cos I search for burned traces and cold joints and now the board it's OK. But the problem still persists: when turned on, the 2950 starts scanning from 26Mhz to 30Mhz. Does anybody have a tip on this subject?
Thank you guys in advance.
Carlos Saraiva
Santo Amaro Island
SouthEast Brazil
saraiva57
Re: RCI 2950 Stuck in Scan mode.
This may help,
http://www.cbtricks.com/radios/rci/rci_2950/index.htm look for CPU faults.
http://www.cbtricks.com/radios/rci/rci_2950/index.htm look for CPU faults.
Rick.
Hello Rick,
Thanks for the tip.
I search for problems on the traces and bad solders and found around 18 soldering points in bad condition. I've soldered all of them (with attention to not make bridges between them, by using a magnified glasses apparatus)
Now FM and AM are working fine, but the initial problem still persists. The CPU is no more scanning from the start (power on) but stopped. Although this, the info of "+scan" is still on the LCD. I follow the tip sent by you Rick, but using a meter to measure if there's ground on CN610 pins 2 and 3. There's no. This CPU number is DPT 295040Z, and there's no jumper J2 to reset the CPU. Do you know how to reset it? I'm thinking in interrupt CPU pin 78, which in the diagram shows "REST" and has "+5Volts" from CN606 pin 5. What do you think about it?
Carlos
Thanks for the tip.
I search for problems on the traces and bad solders and found around 18 soldering points in bad condition. I've soldered all of them (with attention to not make bridges between them, by using a magnified glasses apparatus)
Now FM and AM are working fine, but the initial problem still persists. The CPU is no more scanning from the start (power on) but stopped. Although this, the info of "+scan" is still on the LCD. I follow the tip sent by you Rick, but using a meter to measure if there's ground on CN610 pins 2 and 3. There's no. This CPU number is DPT 295040Z, and there's no jumper J2 to reset the CPU. Do you know how to reset it? I'm thinking in interrupt CPU pin 78, which in the diagram shows "REST" and has "+5Volts" from CN606 pin 5. What do you think about it?
Carlos
saraiva57
Hello Rick,
Thanks for the tip.
I search for problems on the traces and bad solders and found around 18 soldering points in bad condition. I've soldered all of them (with attention to not make bridges between them, by using a magnified glasses apparatus)
Now FM and AM are working fine, but the initial problem still persists. The CPU is no more scanning from the start (power on) but stopped. Although this, the info of "+scan" is still on the LCD. I follow the tip sent by you Rick, but using a meter to measure if there's ground on CN610 pins 2 and 3. There's no. This CPU number is DPT 295040Z, and there's no jumper J2 to reset the CPU. Do you know how to reset it? I'm thinking in interrupt CPU pin 78, which in the diagram shows "REST" and has "+5Volts" from CN606 pin 5. What do you think about it?
Carlos
Thanks for the tip.
I search for problems on the traces and bad solders and found around 18 soldering points in bad condition. I've soldered all of them (with attention to not make bridges between them, by using a magnified glasses apparatus)
Now FM and AM are working fine, but the initial problem still persists. The CPU is no more scanning from the start (power on) but stopped. Although this, the info of "+scan" is still on the LCD. I follow the tip sent by you Rick, but using a meter to measure if there's ground on CN610 pins 2 and 3. There's no. This CPU number is DPT 295040Z, and there's no jumper J2 to reset the CPU. Do you know how to reset it? I'm thinking in interrupt CPU pin 78, which in the diagram shows "REST" and has "+5Volts" from CN606 pin 5. What do you think about it?
Carlos
saraiva57
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beerbarrel
- Dead Key
- Posts: 27
- Joined: Monday 23rd Jun 2008, 4:40
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Re: RCI 2950 Stuck in Scan mode.
It sounds like one of the shift register has gone faulty, you can check this by first removing the keypad and switching the radio on if the fault go away then you have a fault with the keypad.
A common fault is one of the shift register (U605) holding down one the control lines, this is caused by an out of sink clock pulse.
To check this use a scope on Pins 5 and 6, Pins 11, 12, 13, and 14 are used as a latch for the MCU VCREF, if the latch is to slow this causing a bad clock, if will keep the first bit in the MCU up causing one of the functions to stay on.
Check the clock signal at the MCU and the EEPROM (93LC46), also check the serial data in and out of the EEPROM (DO = serial data out and DI = serial data in).
A common fault is one of the shift register (U605) holding down one the control lines, this is caused by an out of sink clock pulse.
To check this use a scope on Pins 5 and 6, Pins 11, 12, 13, and 14 are used as a latch for the MCU VCREF, if the latch is to slow this causing a bad clock, if will keep the first bit in the MCU up causing one of the functions to stay on.
Check the clock signal at the MCU and the EEPROM (93LC46), also check the serial data in and out of the EEPROM (DO = serial data out and DI = serial data in).
Rick.
I did as you said guys but no chance. Even with the keyboard out it keeps stuck on 26.000 Mhz. When I turn on/off it goes to 26000,1 and 26.000,2 and so on.
I also desolder one light bulb leg to see if the temperature on R6 (82ohms- 1/2watt) decreases cos it's so hot that burnt the colored rings around it. But it is still hot.
Maybe you're right. I'll visit a friend that has a scope and if he can help me on measuring the pins.
I'll keep you guys informed
thank you in advance.
carlos
Santo Amaro Island
SouthEast Brazil
I also desolder one light bulb leg to see if the temperature on R6 (82ohms- 1/2watt) decreases cos it's so hot that burnt the colored rings around it. But it is still hot.
Maybe you're right. I'll visit a friend that has a scope and if he can help me on measuring the pins.
I'll keep you guys informed
thank you in advance.
carlos
Santo Amaro Island
SouthEast Brazil
saraiva57