Looks like there is no data from the cpu. Check folowing points:
- Check Q2026 for 5 volt on pin 4, on HF on reception,
- Check Q2033 for 5 volt on pin 4, on HF on transmision,
- Check Q2023 for 5 volt on pin 4, on UHF on reception,
- Check Q2024 for 5 volt on pin 4, on UHF on transmision,
- Check Q2032 for 5 volt on pin 4, on VHF on reception,
- Check Q2025 for 5 volt on pin 4, on VHF on transmision,
Check the connection between J2003 PLL board, and J1025 AF-CTRL-UNIT,
Check if ic Q1119 (BU4081BF) is oke
?
> Check the "VHF-VCO VCV check" and the "UHF-VCO VCV check". If they check ok, then your REF is ok.
> Otherwise check REF, and check if you have output of both PLL's Q2040 and Q2044 pin9.
>?
> 108.000 ? ? ? ? .004 vDC
> 134.995 ? ? ? ?.011 ? vDC
> 140.000 ? ? ? ?.011 ? vDC
> 173.995 ? ? ? ?.011 ? vDC
>?
> I could not locate Q2040 and Q2044 on the PLL board to check them. I located them on the block diagram and schematic. Looking at the block diagram I can only assume they are under one of the four anodized covers on the PLL > > board.?
>?
> Check the voltages on J2001:
> 1 gnd <Ground is good>
> 2 8V. ?<7.90 v DC>
> 3 5V ? <4.95 v DC>
?>?
> J2002:
> 1 gnd ?<Ground is good>
> 2 HR8 8V on reception HF <0>
> 3 HT8 8V on transmit HF ? <.004 vDC>
> 4 VR8 8V on reception VHF <0>
> 5 VT8 8V on transmit VHF. <.004 vDC>
> 6 UR8 8V on reception UHF <0>
> 7 UT8 8V on transmit UHF. ?<0>
>?
> I very much appreciate the guidance on this issue and am certainly going further in depth on this radio attempting to solve this issue. It is a great learning experience for me actually troubleshooting a problem of this > > > level. ?I have replaced components on my other radios but usually something straightforward such as a filter on my Kenwood mobile radio. ?
>?
> 73,
>?
> David AL5M
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.
