Batboard

I purchased a UHF MSF5000 CLB version and it doesn't work... the Proms all look installed but the test light is locked on on the control shelf and it does not transmit or receive... all voltages seem correct and it appears to be powering up normal.

Does any one have another control board or could I send the shelf or board to be tested...I would pay for it of course.

At this point I don't know how to approach getting it working...

Does anyone have a few tips...

Thanks
Phil

Not an expert, but I am now a well informed individual on your specific issue.

Bernie pointed this out to me and it solved 6 out of 7 problems. I had the same thing you have with not one but three different controller boards, the test light on steady. It can mean other things but here is what fixed mine.

On the controller board near the side housing you will see a little metal can about 2 x 2.5 inches. If this metal can is there, take it off and leave it off. This is a switching power supply for the controller. But, mor importantly there is two capacitors next to this can. One is a silver radial style capacitor a couple of inches long and will have 2 leads coming out of one end. That end will probably have a red cap, and will likely show some brown discolorization from that end. The other end is a single lead and is only used to "tie down" the capacitor. The operating leads are on the two end side.

Right next to it is another large electrolitic capacitor, radial style, with one lead out each end.

You need to replace both of these caps with 1000uf 35 volt caps. The dual lead cap can be replaced with an axial cap as the two leads are right next to each other, the other one can be a radial. I have done this on all but one of my current analog controllers and it fixed the three that had the bad (test led on) problem.

Additionally, for the challenge of it, on the Interconnect board found under the RF tray is yet one more of these three leaded radial caps. Bernie says these should be changed as well but are a bit trickier to do. If the RF tray is out of the cabinet, then it can be done without removal of the board, otherwise it needs to be removed and that involves lifting the uniboard and unscrewing some connectors (bypass/feedthrough cap assemblies) so that the board can be removed out the bottom. I haved only done one of those so far, but the controller board problems went away once the two caps were replaced.

Good luck!

My two bits worth:
That is exactly what I said.
After that is solved be sure to tune the VCOs and check Receive meter 3.
(This requires a test set)

The capacitor in the 5 volt section of the of the controller was the problem...

As soon as I piggy backed a new cap across the old one things went to normal...

I replaced the cap and its working perfect.

Thnaks again,

Phil