Over The Air > Ham Radio Circuits and Repair

President HR 2510 CPU/PLL issues

<< < (2/3) > >>

Robb:
I tested the three SMD varactor diodes (D305, 306, & 307) in the voltage adjustment circuit and they all tested OK.  Here is a strage factor: I can hear a change in the static volume level in the speaker when adjusting L317; it sounds like it is working.  But the test point shows no change in voltage at all; still reads 7.15v.  Very odd; wrong ground location for the meter?  Hmmm... 

So at the other side of this equation would be the NJM3404AS or the PLL0305A at fault.  Doubt that the S042P has anything to do with what looks like a short condition in one of these other device (yes; a guess), since it is a mixer chip at the receiving end of this chain.

Going to have to test the NJM and the PLL at their pins and see if anything is amiss.  Gonna have to go with the datasheets, since the schemo doesn't show voltages/signals values.

Thoughts?

http://www.cbtricks.com/radios/uniden/hr_2510/graphics/uniden_hr2510_cpu_sch.pdf

Robb:
I understand thru another source that these CPU boards have their own issues.  Is there a link to any page that has documentation?  Couldn't find anything on the net that was worthwhile or complete.

Thanks!

Robb:
:hearing crickets?:

The Radio Shop:
Robb,
Sorry, not much time to internet here. Been so busy with work.
I do not know of any links about the cpu board.  There is not a lot of information out there on these. If I find something I will post it up for you.

UncleBobo:
If you can get access to a working unit, swap CPU boards to make sure that is the problem area.

Navigation

[0] Message Index

[#] Next page

[*] Previous page