malc-c

Just a word of caution... If your EQ6 has one of the D9 connectors for the handset and you have purchased a standard USB to Serial adapter that has a D9 plug on one end and a USB port on the other then there is a very high (almost certain) risk that you will damage the motor board. This is because true RS232 to USB adapters ramp up the voltage to +/- 12v (yes a potential of 24volts) which when fed to the serial pins on the processor blow the EUART and render the communications useless. In such cases the only action possible to restore the mount to working ability is to replace the damaged controllers containing the firmware for the model of mount.

Can you post a picture or give more info on the "dongle". Most EQDIR cables look more or less like a standard USB -A cable, but are terminated with the same RJ plug (other then the older EQ6 mounts that have a D9 plug). So there is a direct connection rather than via an convertor / "dongle" When connecting any mount with an EQDIR cable that plugs into the handset port on the mount will run at the default 9600 baud rate. On newer mounts that have a built in USB -B port and can use a normal USB A-B cable the USB bridge (the chip that does all the work) is a Prolific 2302 chipset that runs at 115200 baud. As mentioned above there are several versions of prolific driver so worth running the tool to help aid downloading the correct driver if the device has a Prolific chip. Most 3rd party EQDIR cabes such as those made by Lynx use the more widely supported FTDI chipset which is plug and play under windows.

I don't think it was ever produced (I'm not the author of the chart). I don't think there is any difference between the RA and DEC

The "no response XX or YY or both axis" message means there is a break in communications between the handset and the control board. The handset regularly expects replies back to its communications and if it doesn't get them it reports the error message. The cause could be anything, from a dodgy connection between the handset and curly cable, the curly cable and the mount, and the connector to the internal EUART port of the processor on the motor board (the latter has been the case when the wrong cable gets plugged it to the handset port and blows the serial port in the microcontroller(s) ). On the older motor boards that use Microchip PIC microcontrollers (16F886's) the TX line is common'd through two signal diodes, and if one of those fail, or if moisture provides a path across them this too can result in the same message appearing.

Did you use the correct firmware. There are two versions of motor board used with the mount. Version 2.07 is for older mounts which are PIC processor based, where as the version 3 is for newer mounts which use the ARM based boards. If your mount has a built in USB type B port then you need version 3.xx firmware, if it lacks the USB option then use 2.07. If you find that no matter what you try the issue continues, then assuming nothing else changed and it was perfect before patching the firmware then either it has been corrupted in the process, or one of the driver chips has an issue (my bet is that its firmware related). If your mount lacks the USB port and is PIC microcontroller based then its possible to flash the firmware direct using a programmer, or if the chips have failed then they too can be replaced. I've repaired dozens of motor boards where the PICs have been physically damaged so all is not lost. However if the mount is newer and ARM based then I lack the tools to replace them so a new board would be needed. Normally revised firmware is only needed if your mount suffered from the issue that the patch was published for. There is often no need to flash the firmware if the mount is otherwise working perfectly. If you are unable to resolve the issue (not sure if bricking the mount due to a problem when flashing the firmware is covered under warranty) and the motor board is of the older type then drop me a PM and I'll give you details on how the have the board repaired.

The scopes are manufactured by Guan Sheng Optical (GSO) in Taiwan. FLO are the importers and brand them as "StellaLyra" From limited research via google they seem to have a good reputation but how they compare to scopes made by Synta (Skywatcher / Celestron) might be subjective. Maybe drop FLO an e-mail for details as they could confirm what choices will work, and if collimating one of their F4 newts would be any more challenging than an F5

I would still replace it with a Schottky barrier rectifier diode that has the same 40v, 3A forward current (70A peak) rating. It doesn't need to be a surface mount component, a normal radial through hold package will do so long as you can solder to the pads where the diode is mounted

Which probably highlights the possible reason I've had so many motorboard to repair. Why manufactures don't standardise the connections across all their products I don't know...

Without any details it's impossible to say. The 16F886 has been around for some time so should be supported by most programmers. I use the PicKIT2 (now superseded by the PicKIT3 and PicKIT4 ). You will also need an adapter to hold the 28pin SOIC package. This is my setup I use to program them, the clam socket and PCB was kindly sent to me a couple of years ago from a fellow SGL member. Prior to that I was using a 28 pin SOIC breakout board and a sprung clothes peg

Richard, I did consider a direct connection to the pins of the RJ45 socket, but with an 80 pin package, and not knowing if the firmware is written to use com port 1 or 2 (or should that be com port 0 and 1?) and the fact that I don't have anything thin enough to solder I shelved that. But now you have done your best to trace out the path, at least to points where the solder mask can be scrapped back to expose the tracks and enable a ware to be soldered might give me something to work with. - Many thanks

Nope - Handset to mount is RJ45 both ends (same as cat5 ethernet) - If the OP uses that cable with the EQ5 synscan, it could be coming back yo me for repair !

David, thanks for the info... I wonder how many designers have gone back to the accountant and said "told you so" after such practices are employed.

That's very interesting.. I wonder what that small 8 pin package does. It does seem that the same via's are all connected to one side, with the same trace running to the second from left pin on U8. I wonder which revision came first? What strikes me is that major manufactures of graphics cards make active schematics and component ids available, but try and get the same from Synta... you have more chance of finding fairy dust ! Anyway, this handset will sit in the draw until someone else ends up cracking a screen or something that can be fixed by swapping parts over.

That's my guess too. Something could fail, allowing a new path for the current to flow, which then has a domino effect allowing higher voltage to reach low voltage components.

Thanks for the images, and ID of the part U6. Like a lot of parts in Chinese electronics those that do have labels are often non traceable. But even then if I could find out what it is I don't have the tools to replace it. My logic was that regardless of which port is used the TTL signals end up at one of the two USARTS on the processor, so once a suitable place was found I was going to see if adding a couple of wires directly from the pins of the handset port to the pics serial port pins. However looking at the datasheet for the PIC18F85J10 I can see that whilst the chip is a low voltage package, the digital pins are 5.0v TTL level tolerant

unlike the ferrite bead, 3/4 of U6 remains !! I'm also interested in what the small three wire connector does as the USB to serial chip would be used if the handset was to be used as a pass through. The fact you could have either an EQDIR cable connected to the PICs serial port, or use the USB port suggest that the TX and RX must be linked, and that three wire could be the TX/RX and GND from the onboard USB/TTL serial chip. Anyway, its almost 1.30am so time I retired to bed ! My gut feeling is that whatever vaporised the Ferrite bead may have also blown the PICs Euart and I lack the skill, tools and eyesight to remove the 80 pin package, fit a replacement and then program it !

Thanks for the suggestion. Does FB4 connect to the 3rd pin from the top as viewed ? If you look at the image I posted I have a a good trace between the 4th pin form the top and pins 7&8 (+12v in from the mount) so no need for the diode. I have also noticed U6 next to the crystal is a little charred but there are no pads or legs, so guessing its a BGA type package - but its very small ?? I've spent best part of 5hrs play with it and can't see any possible fix - even checking continuity for both Euarts on the 80 pin 18F Pic to the 6 pin connection cable header at the top of the main board doesn't ring out... I was hoping that with some delicate soldering of some fine wire I could just take the TX/RX directly out to the daughterboard

A Ferrite bead - Which looking at this thread seems to be one of the two Achilles heals

Another bitter sweet success today. I received a synscan from an EQ5, along with a handset and cable from a fellow SGL member today. The handset was displaying the normal "No response both axis" message so it was a case of replacing the PIC with a new one having first programmed it with new firmware. I downloaded the latest 2.7.02 firmware and converted the binary into a HEX file and uploaded the code to a new 16F886. It was then that I thought I would document the process of replacing a PIC if all you have is a soldering iron and don't have access to a hot air solder station, as I get asked about this so many times. So here are a series of images to best help explain the procedure. The first thing to do is to cut the body of the old PIC away from the legs soldered to the PCB. You can use a mini drill with a small cutting disk, or use a small file to separate the legs at the point where they enter the package. Once you have done that the body should drop away, leaving the legs in place Apply some flux to the pads where the legs are attached. I use Amtech flux, which whilst being expensive is very good at what it does. Then with the iron set to 350c, you'll find the legs will easily come away when the iron is applied. Once all the legs are removed a liberal application of Isopropanol Alcohol IPA (99.99%) and a wipe with a piece of kitchen towel cleans the board up and removes the residue flux. Place the newly programmed PIC on he PCB and when you are happy with the placement, solder pins 1 and 15 (or 28 and 14 - so long as they are diagonally opposed) to hold the PIC in place. Then apply some more flux to the pins and after tinning the soldering iron start soldering each leg in turn. The flux will ensure the solder flows well and makes a good joint. Once all the legs are soldered give the board another spray of Isopropanol Alcohol IPA to remove the residue of flux and and that's it... Job done! Now it's just case of testing, and for that I use a specially written application which sends off a load of commands to interrogate the mount and log the response it received back. This confirmed the repair was a success. However when the board was tested with the handset I still got the same "no response " message, so further investigation was needed and upon removing the rear casing of the handset I got a whiff of burnt electronics and upon inspection found a hole burnt into the daughterboard, which sadly wasn't repairable. So there you go... I hope this step by step guide is useful. However if you do have a faulty board, are based in the UK and still feel this is out of your comfort zone then drop me a PM and we'll sort out getting the board sent to me for repair

Update: I've been in conversations with Lawrence via PMs and he sent me his handset, curly cable and synscan unit, which was received today. I plugged the handset in and confirmed the same message was present. Powered down and replaced the handset with my FTDI EQDIR cable used with my HEQ5, and having powered the board back on opened up the test program which reported no response / mount not present, which confirmed the PIC's serial EUART was damaged. I downloaded the latest (2.7.02) EQ5 firmware for the synscan box and converted the binary file to HEX and programmed a new 16F886 with the code. The synscan unit was disassembled and and the board removed. The old pic was removed and the newly programmed one soldered in its place. The handset was connected and power applied. I was gutted to see the same "no response both axis " message, suggesting there may be more to this than I first though. So I reconnected my EQDIR cable and ran the test program once more. I was pleased to see the report showed it was fully functional. I also backed this up by launching the SW firmware application which read back the firmware without issue. So I look the back off the handset, and was greeted by that lovely unique smell of cooked electronics. Seems a ferrite bead got so hot that it not only completely burnt itself out, it managed to take a layer out of the PCB, exposing the fibre glass below... On cleaning it was found that part of the track was floating, and was beyond my skill to grind the board away patch it and then try and protect the parts. Plus there was no guarantee that no other damage to the ARM processor's communication port had been done, and if a bodge repair was made that it would work. So the now working synscan unit was packed back up along with a print of the report and boxed ready to go back to Lawrence. Given the damage to the handset Lawrence was willing to donate the handset to the cause and told me to keep the it as it might come in handy should someone have the same version handset with a cracked screen, or one with a blown Q3 MOSFET. I believe Lawrence is looking at purchasing a replacement handset which should restore the mount to full operation. Just like to than Lawrence for giving me the opportunity to work on the board, and for donating the handset to me, just sorry that I couldn't achieve a 100% fix

I have no idea, but might be worth posting the question on the EDMOD user Group https://groups.io/g/EQMOD Might be worth installing a different planetarium application such as CdC and see if you get the same drop out... if you do then it would rule out Stellarium as being the casue

I used to work for Epson around 25 years back and my job involved European travel. Their Italian office was based in Milan and I agree with you, it's a very nice place, especially if you eat where the locals eat rather than the tourist area's... Fantastic pasta dishes and lovely bars that were open well into the small ours of the morning :-)

PIC Programmers are very cheap, the adapter to hold the SOIC packaged PIC is typically $30+ plus shipping. Ebay would be the best place to look for a PICKit2 or PICKit3 programmer and adapter. But then you could be spending 40+ euro on something you would probably only use once, and it would be better to put that money towards a new board if the repair shop is unable to help. Another option is to contact a local school or college to see if they have the hardware and could help you out, either as an electronics club if they teach electronics.

Just to clarify the port on an EQ6 / NEQ6 that has a D9 port does not run the serial lines at true serial voltages. The TX and RX lines are TTL level, 0 to 5v. The problem is that next to the data lines there is +12v and GND so what you have probably done is basically shoved 12v across the data lines and blown the EUART port of both PIC micro controllers. The only way to fix this is to follow the steps in this thread to program two new 16F886 microcontrollers, desolder the existing ones, being carful not to lift any pads and damage the tracks, and then solder the newly programmed microcontrollers in their place. Prior to Christmas I could have sold you a mainboard that already had the repair undertaken as I had several spares due to other members kindly donating blown boards to me after they had already gone out and purchased a new replacement control board. However I no longer have any as they have all gone. The other problem is that as you are in Italy the cost of shipping the faulty board for repair will be expensive as it needs to be insured and tracked. Due to issues I've had with sending replacement micro controllers and a control board outside of the UK I can only take in boards for members based in the UK mainland. Replacing the microcontrollers isn't that difficult, but unless you have or can find someone with a PIC programmer who can program them for you it's pointless to try. The HEX code for an EQ6 has been attached (assuming the forum software allows that). If a repair is not possible then the only alternative is to replace the old board with a new one. If you do choose that option, then please consider donating the faulty board to the exchange program and send it to me by the cheapest postal service (no need to send it insured or tracked as its faulty anyway, should it get lost in transit). EQ6-NCP.hex

IMO to be able to do 2min exposures unguided requires either precise polar alignment, or a higher precision mount. I have an observatory based set up with an HEQ5 that is polar aligned to less than 10 arc seconds, but would still guide on anything over 60 seconds exposure. Now the field of view on your lens may be wider than having the body attached directly to the 150P, so exposures could well be shorter, or any errors in alignment or tracking would not be that noticeable. I guess it all depends on the seeing conditions, the darkness of the site, how tuned the gearing on the mount is and how well your PA is... That's the fun of this hobby, a lot of times you just have to try things out to see it they work.