[amsat-bb] Elevation meter Rotor YAESU G-5500 stopped working

[Norm n3ykf]

If the box is driving the tracker (that's what he says), it's not
external. Time to get the screwdriver.





On Tue, Jul 18, 2017 at 8:01 PM, W3AB/GEO <w3ab at yahoo.com> wrote:
> Norm,
>
> He should make sure it is not an external issue before he dives into the
> internal circuitry.
>
> He should also check that the controller is operating before opening the
> controller.
>
> Albert, take a VOM, set it on AC and the 50V range if it isn't autoranging.
> Turn on the controller. Put 1 lead on pin 6 of the terminal strip, the other
> lead on pin 4 and operate the up/down switch. Do the same for pin 5. If the
> controller is operating correctly you should measure ~30V. If not, you have
> an internal failure and follow Norm's advice.
> ___
> Sent from my two way wrist watch
> 73 de W3AB/GEO
>
> On Jul 18, 2017, 16:50, at 16:50, Norm n3ykf <normanlizeth at gmail.com> wrote:
>>Albert,
>>
>>Take EXTREME CARE working on equipment that has power applied.
>>
>>You'll need a copy of the schematic. Preferably the one that came with
>>the controller/rotator. There are at least two different power op-amp
>>power supply layouts. One with a pass transistor and zener diodes, the
>>other a 75L10 regulator.
>>
>>Unplug the control box.
>>
>>Remove the top cover. Remove the front two screws from the bottom
>>cover. This will let the face (meters, circuit board and switches)
>>free. (still wired to the rest)
>>
>>Get two books. Turn the front face down on top of the books, switches
>>between the books. (to allow the assembly to sit level and not
>>press/break the switches)
>>
>>
>>MAKE SURE THE UNIT IS UNPLUGGED!!!!!!!!!!!!!!!!!
>>
>>
>>Q4 is one half of a 4558 op amp pair(two on one chip, the other runs
>>AZ output for the aux jack).
>>
>>Find Q4.
>>
>>You're mission is to check the various components making up the drive
>>circuit for the EL meter for trouble.
>>
>>Could be:
>>
>>Shorted capacitor
>>
>>Open diode
>>
>>Short or open via other means.
>>
>>MAKE SURE THIS IS UNPLUGGED!!!!!!!!!!!!!!!!!
>>
>>Use an Ohmmeter to look for capacitors that aren't open (Should look
>>close to it, at least the values in the circut. Electrolytics are a
>>different story...) Look for open diodes. Meter anything reasonably
>>accessable, starting from the wiper on VR2 on the back panel. Some
>>things are best looked at with respect to ground, others point to
>>point reading the components in between.
>>
>>DANGER!!! DANGER!!!! DANGER!!!
>>
>>This part of the test requires making power on voltage measurements.
>>Here be dragons, or a trip to your eternal reward!!!
>>
>> Locate L2 and L4. Those components (each in their seperate circuit)
>>form the power supplies (rails) for the EL op amp. See C1 (the voltage
>>output) next to L2? C2 likewise next to L4?
>>
>>Check the pins 8(C1) with respect to ground and 4(C2) of Q4. These are
>>the power supply rails (should be +/- 12 volts or so).
>>
>>Before plugging it in to test, make sure no bare wires are touching
>>things they should not be.
>>
>>Plug it in (you did leave the power switch on, didn't you??). Test
>>away. UNPLUG IT AS SOON AS YOU'RE DONE!!!!
>>
>>Have fun and don't break anything. A fire here is a failure.
>>
>>Norm n3ykf
>>
>>On Tue, Jul 18, 2017 at 5:56 PM, Albert van Deursen <avdeur at home.nl>
>>wrote:
>>> Hi all,
>>>
>>>
>>>
>>> All of a sudden the elevation meter stopped working of my Yaesu
>>G-5500 rotor
>>> controller unit .
>>>
>>> No issue with the AZ meter. Rotor itself keeps on steering / working
>>> without any problem in EL &AZ (via interface EA4TX ARS-USB) so all
>>still
>>> working fine (fortunately !)  for satellite work.
>>>
>>> Looks like a component failure in the controller unit  or the meter
>>itself ?
>>>
>>>
>>>
>>>
>>> A physical check (opening the controller unit) didn't show any
>>anomaly.
>>> Being a not too tech ham was wondering if any of you Yaesu rotor
>>users had
>>> seen this problem before / around ?
>>>
>>>
>>>
>>> Possibly anyone to hint/ indicate at a quick check in the schematic
>>wire
>>> diagram to where to start looking for this failure ?
>>>
>>>
>>>
>>>
>>>
>>> Thanks beforehand for yr appreciated advice
>>>
>>> 73
>>>
>>> Albert
>>>
>>> PD0OXW
>>>
>>>
>>>
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>>_______________________________________________
>>Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
>>to all interested persons worldwide without requiring membership.
>>Opinions expressed
>>are solely those of the author, and do not reflect the official views
>>of AMSAT-NA.
>>Not an AMSAT-NA member? Join now to support the amateur satellite
>>program!
>>Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb