MSF5000 issues

[AllStrobedUp]

So I have a 1988 MSF5000 UHF repeater. It has been working great for years. The other day it stopped working and I have the following errors, E40,41,47,49. The pay key is dimly lit and everything else is off. I don't even know where to start troubleshooting.

 

[RFI-EMI-GUY]

I would start with power supply voltages and ripple.

 

[petnrdx]

Like I said, check in the email, check power.
If both RX and TX VCO'S aren't working, its a supply problem that affects both.
Might be a electrolytic capacitor that is shorting out.
CAREFULLY tilt up the SSCB and check for hot components with your finger tip.
All the manuals are available online.
Seems to me (by memory) that there is a 5v regulator circuit on the SSCB, might be the first one to check.

 

[AllStrobedUp]

I would start with power supply voltages and ripple.

It is idling at 15.9, cant get it to key.

 

[RFI-EMI-GUY]

It is idling at 15.9, cant get it to key.

Seems a bit high, however that may be the PA supply which is "regulated" from a ferroresonant transformer and may be that high. You need to look into the internal regulation for the station control board. I suggest determining your exact model number of the power supply and the station and consult the exact manuals pertaining to the station. You probably have a regulator or capacitor that is bad. Can you put a scope on the station and check for ripple?

The Motorola MSF and PURC Index page

 

[AllStrobedUp]

But of an update. Checking the test points I am only getting 1.33v on the 9.6 volt test points. None of the caps are warm or appear to be damaged or leaking.

 

[RFI-EMI-GUY]

But of an update. Checking the test points I am only getting 1.33v on the 9.6 volt test points. None of the caps are warm or appear to be damaged or leaking.

Well that would certainly be a clue.

 

[AllStrobedUp]

I think I need to find someone that I can send the SSCB to for in depth troubleshooting and repair.