I'd like to thank Jack Hackett for his earlier advise. I was at a mental roadblock and your suggestion, although not the entire solution, at least got me off dead zero.
I checked for the 5v DC-DC. Sure enough, my DS710 was not lit (..that's the li'l green LED that only lights up when all voltages, A+, 9.6, AND 5v are present)
Motorola engineers were on thier game the day they thought up JU8. If you pull JU8 and get a good DS710, than the 5v DC-DC is good and it's got a short circuit downstream somewhere.
So what I did next was to systematically pull interconnect ribbons off while pulling and replacing JU8. My 'short circuit downstream' appears to be on the radio side of P801. That's the connector that heads off toward the transmitter/receiver section.
Now that I've gotten that far...I hit another mental roadblock. I'd appreciate anybody's suggestion as to how to find my short.
Thanks loads!
Bill
Continued MSF 5000 problem
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i betcha
it's your IPA
that's where 9.6v is made
among other things
doug
that's where 9.6v is made
among other things
doug
I seem to recall that when the +5v on the control board dies, it also takes the +9.6v regulator on the IPA with it. Maybe they weren't entirely on their game that day ! Could have added a couple more parts to at least protect it from catastrophic damage.
Thanks to the wonderful current manuals for the MSF5000, you probably don't have any schematics for anything except the Uniboard inside the RF chassis. If you need details of certain areas, I do have a complete manual and would be happy to scan a few pages and send them to you. Leave me a PM with your e-mail address and the stuff you think you need and I'll get it out in the evening.
Bob M.
Thanks to the wonderful current manuals for the MSF5000, you probably don't have any schematics for anything except the Uniboard inside the RF chassis. If you need details of certain areas, I do have a complete manual and would be happy to scan a few pages and send them to you. Leave me a PM with your e-mail address and the stuff you think you need and I'll get it out in the evening.
Bob M.
My two its worth:
If the 9.6V fails it may damage the 5V switch transistor.
The analog station powers the receive VCO circuit via pin 9 on the ribbon cable.
The Digital station has no 5V used on the casting as far as I know.
I am on vacation, and do not have a manual handy.
Keep looking.
If the 9.6V fails it may damage the 5V switch transistor.
The analog station powers the receive VCO circuit via pin 9 on the ribbon cable.
The Digital station has no 5V used on the casting as far as I know.
I am on vacation, and do not have a manual handy.
Keep looking.
Aloha, Bernie
My two bits worth:
Now that I am a senior citizen at 62, my memory is not as good as it used to be, so I come back to the Chicago area to remind me why I got out of here 40 years ago.
Actually, I am visiting family, and friends.
My brother lives in Barrington, IL
I rent a car and drive down to Horse Cave, KY to see my friend Bill Kidd,
That I hired 32 years ago in Hilo, and then to Powell, TN to see another friend that is a master clock maker. ( I am also a clock, and watch maker)
No, I do not get "rock fever".
Come and visit some time!
Now that I am a senior citizen at 62, my memory is not as good as it used to be, so I come back to the Chicago area to remind me why I got out of here 40 years ago.
Actually, I am visiting family, and friends.
My brother lives in Barrington, IL
I rent a car and drive down to Horse Cave, KY to see my friend Bill Kidd,
That I hired 32 years ago in Hilo, and then to Powell, TN to see another friend that is a master clock maker. ( I am also a clock, and watch maker)
No, I do not get "rock fever".
Come and visit some time!
Aloha, Bernie