HEQ5 parts (boards)

[RobF]

Does anyone know if you can buy any of the boards for a HEQ5pro? I fried something internal ages ago putting together my first TTL/USB cable for EQMOD :P
Fortunately it's worked wonderfully without the handcontroller (once I corrected my dodgey wiring), but I would like the option to run it autonomously.

Any thoughts?

I've tested the controller on other mounts and fine. Get an M.C. error when try to connect to the HEQ5.

[Poita]

The board may be repairable. If you know what pins received the unwanted power we could trace out the likely component failures and perhaps replace them.

[bojan]

Probably just MAX232 (or similar) is fried?

[Poita]

That was what i was thinking, a repair is probably quite feasible.

[RobF]

Cheers guys, I was hoping (but dared not expect) there would be people here with knowledge and skills to troubleshoot the board. I've recently purchased an EQ6 to find out for myself the difference over HEQ5, and once that's running smoothly I'll feel a lot better about messing about with the insides of my trusty 5. Would be quite happy to try and rescue the board by soldering out components if possible. Are the chips MAX232? hard to come by?

Can anyone point me to a guide for pulling it down far enough to expose the electronics? Most guides out there seem to be for the more common EQ6s.

(might be a few weeks before I can attack this and come back for advice - around Easter perhaps)

[keni]

Hi Rob,
I sent you a PM re your problem.

Ken.

[rally]

Do these mounts use a MAX232 ?
I thought they were TTL all the way through the serial chain

I have never owned one though.

Rally

[Poita]

http://www.astro-baby.com/heq5-rebuild/heq5-m1.htm

http://akadem.us/astro/manuals/HEQ5%20Upgrade%20Kit%20240505V1.pdf

Bottom link is probably what you want.

[BPO]

Hi. I've had no problems buying replacement boards for my EQ6 mounts (upgraded from old v1.06 PCBs to the latest v2.0x), so replacements for your EQ5 are likely available too.

[bojan]

This could be the case - remains to be seen.
My (classic) EQ6 was TTL between hand pad and controller board.. but maybe they changed the philosophy in the meantime.
It's not hard to see what is actually on the board anyway ;)

[Barrykgerdes]

The levels are TTL but I gather there would be a buffer on the signal lines similar to LX200's keyboard.

In which case the most likely place to have the trouble you experience is there. LX200's use 74LS74 hex buffers that are the first things to go if you get 12v on the wrong line. They eventually put snubber diodes on them to handlle problems.

I don't know what is used on the EQ drive boards but tracing the tracks on the PCB should reveal it. Have you put an ohm meter on the signal lines. If so what is the reading.

Barry

[peter_4059]

It's got to be TTL because the cable you use for EQ direct plugs into the hand controller port on the mount and uses TTL signals.

http://www.dontronics-shop.com/ftdi-usb-to-serial-ttl-level-5v-converter-cable.html

[RobF]

Thanks guys - at least those guides Peter posted give me an idea how to get into it.