Problem with AM5N : Page 5

Problem with AM5N

Pedro

Ws2n957M
We seem to be at the mercy of ZWO Support in China.
Unfortunately, I do not have to date any evidence that such department at ZWO exist as they have yet to acknowledge any of the communications sent. ZWO Support in the USA responded but were quick to point out that I will have to pay for shipping, repairs and custom fees, even if I bout my mount less than two months ago from StarTrip (AliExpress) - Vendor not offering any support neither.

Ws2n957M

Pedro I've started exchanging with their support via mail, but haven't seen much progress so far..

First exchange with ying.tang@zwoptical.com went well, then I tried their suggestion (mount software update, 50% aggr., 0.5" exposure, belt tightening) and... they fumbled on wednesday and replied to me using someone else's logs.

It can happen, I get it, but I hope they'll be able to provide more substantial help in the coming days.

I've sent another round of investigation and logs their way just this morning, very similar behaviour when switching to my C9.25 + OAG + 7kg counterweights, on a different target. Instability appears from _60° and then vanishes after meridian.

Pedro

ASIMount-ZWO
Despite your assurances and the contact information provided, ZWO Support China has yet to acknowledge, let alone respond to any of my emails or communications. This includes multiple messages containing logs, images, and additional files intended to assist in identifying the root cause of the issue.

At this point, I’m unsure which is more frustrating:
1) Repeatedly experiencing RA excursions night after night,
2) The lack of response from ZWO Support China, or
3) Having placed trust in ZWO’s claims of delivering a high-performance, reliable mount.

F5146666

jb.matross

May I ask which mount firmware version you used?

Andreas

jb.matross

F5146666

1.7.7

Pedro

I have just been outside and as suggested pointed the OTA to the west (telescope at the East of the tripod) and experienced the same departures as described in my contributions to this forum. I then pointed the OTA to the East (telescope at the West of the tripod) and to the departures on the RA channel continued but worse with fair amount of cross-talk to the DEC during peaks. I have 9 Kg counterweights at 16cm to balance an Askar SQA106 and 2600MM Air, EAF CAA and EFW. Connected the AM5N via Bluetooth and USB cable, no difference. tried 0.25X and 0.50 Sideral from 25% to 50% Aggr, no difference. 1000ms calibration step and 500ms, Darks and Gain selected at 250 and 350, no difference. Checked belt tension and both motors have good feel. Commanding movement on RA or DEC happens without jumping teeth as far as I can tell. Firmware is 1.7.7. Mount directly and independent powered by 60W 12V supply. 2600MM Air, CAA, EAF, EFW powered separately by its own 72W 12V supply. Tripod confirmed level prior session, seating firmily on concrete slabs without movement. PA completed twice and twice confirmed deviation below 15" on RA and DEC before staring session. No cable snags or dragging. All USB cables checked before installation working flawlessly.
Changed the Askar SQA106 in its entirety to the iOptron CEM40 EC next to the AM5N and after PA and PHD2 calibration, guiding below 0.50".

The above strongly suggest that IT IS THE AM5N MOUNT...!!!!

All subs tonight look like this:

Despite promises from ASIMount-ZWO that ying.tang@zwoptical.com was going to contact me very soon, two weeks have passed without anybody from ZWO Support contacting me in any way or capacity. I have been completely and totally abandoned with a faulty mount that does not perform as advertised.

Ws2n957M

I've done a few additional rounds of debugging on my AM5n, with a second attempt at tightening the belt.

What I find interesting in my case is that it seems to consistently start failing when approaching the 60° equatorial circle, between there and the meridian it goes bonkers

This is before meridian:

The point where it starts going off-rail is where it reaches the red section in the following sky map:

And this is after meridian:

phd2-guidelog-2025-08-09-233022.txt

2MB

ppurbano

We're still waiting.... Thank you so much ZWO for leaving us stranded for a whole summer.

KHj89YaN

Hi,

To add more visibility to this issue, I'm leaving this post as it is summarizes and details that the RA Guiding issue for these mounts is becoming potentially a more widespread problem. I'm only reporting on the growing prevalence of this issue. The details in this current thread should also cover the points brought-up in this reply, however; I am posting it here since there needs to be visibility regarding this problem and that normal technical trouble shooting by the user are not suitable or acceptable at this point.

There have been other users in different threads on ZWO, social media boards/threads, and other astrophotography sites (I don't want to name the sites incase that's a violation of forum rules) that the procedure to tighten or loosen the RA belt is not effective. Users have reported, in the United States, that after submitting and completing a RMA, the issue was not resolved by ZWO USA and continued. Likewise, the replacement of the mother board by ZWO USA in the mount was also not successful. Adjusting PHD2 settings is also not effective, based on the posts, since it appears to be a systemic mechanical issue, not software. There appears to be a repeating RA guiding spike at every 280-300 seconds which roughly aligns with the RA belt cycle completing. Users have reported that they have carried out all ZWO and ZWO USA suggestions for checking for loose connections, power supply, mounts, and outdoor conditions and have found the issue still persisting. Additionally, there are users that have the AM5N mounts at remote observatory sites and have had the staff run through the ZWO/ZWO USA trouble shooting suggestions without resolving the problem.

This RA guiding problem appears to be affecting both later model AM5s and AM5Ns purchased from 3rd-4th Quarter (August-December) 2024 with PE Tests done during the same time frame. I have been monitoring the occurrence of posts regarding this problem since May 2025 and there has been a gradual increase of users posting about RA guiding issues with these mounts to the point that RA guiding/tracking is no longer possible making these mounts unsuitable for imaging.

Again, I'm posting this for visibility since there are a number of these posts alone on ZWO and are not in one spot.

Tech@ZWO

Hi everyone,

Thanks a lot for sharing your experiences and feedback. We really understand how frustrating guiding issues can be, and your feedback helps us a lot in tracking down what’s going on.
Up to now, we’ve only received a small number of cases where the RA guiding spikes show a repeating cycle, and a few mounts are already being tested closely. At this point, we haven’t seen anything that points to a batch-related problem.

If you notice similar behavior, we’d recommend starting with the AM5N guiding parameters we suggest.
Max RA DEC duration 500ms
Exposure time 0.5-1s
Aggression 40%-60%
And if possible please also try latest version AM5N firmware.

If the problem still shows up, please drop a message to our support team here https://support.zwoastro.com/
And please include your guiding logs
firmware/software versions
Mount SN
and anything you’ve already tried.
The more details we collect, the faster we can get to the bottom of this.

We really appreciate your patience and support—it means a lot to us. Thanks again for helping us make the mounts better!

KHj89YaN

Tech@ZWO

Thank you for your response. I think it would be advisable for owners of the AM5N purchased during the August 2024-December 2024 to submit an RMA claim to get their AM5Ns into the system. I understand from a statistical standpoint that ZWO is still approaching this problem as contained or isolated one-offs, however; it appears that owners of the AM5N are not aware of submitting an official support ticket or an RMA https://rma.zwoastro.com/#/index. Therefore, the actual issue count is probably under counted.

I will also note, the ZWO suggestions as mentioned here were ineffective in resolving the guiding problem. Both ZWO and ZWO USA have made similar suggestions to users with no resolution to the RA guiding issue.

I am responding for visibility for this issue and to detail that there are a number of increasing posts regarding RA guiding issues with the AM5N over the last three months and those users have yet to have ZWO or ZWO USA successfully resolve the problem.

Kevin_A

From my long experience using ASIAIR and the AM5, is that all the above suggestions are good baseline numbers. The biggest improvements on top of those numbers is a small 0.1px minmo (trigger accuracy) and using a smaller guide pulse rate of 0.25 X instead of the standard 0.5X. My mount only has trouble now if the sky turbulence is bad but my guiding went from 0.7rms down to 0.46rms consistently without many spike anomalies. The guide pulse rate made the majority of the improvement as is stops it over correcting from jittery guide stars using fast guide exposures.

KHj89YaN

Kevin_A

Hi,

These are all good details, however; it appears that this issue and the problem not being resolved with ZWO's guidance is affecting AM5N model mounts that were sold between August 2024 and December 2024. The original AM5 has not been reported on other sites as having the same type of persistent issue. Some AM5N users have reported that even after having its original board removed and replaced the issue returns. ZWO USA Repairs has also confirmed that what they are seeing are, although a small number of mounts so far, AM5Ns from that time period with this issue. I theorize that this RA guiding problem is probably under reported since users are creating threads on astronomy site forums and social media sites instead of submitting tickets.

marci

Hello,
I opened a support ticket ZWO20250618351853-SZ on last June after a month of many tests. Mount was shipped on end of June to Optique Unterlinden (french SAV for Zwo devices).
My ticket was closed by Zwo support and I'm waiting for my Mount to be repaired. OU confirmed periodic RA spikes issue.
In France, law say that a provider have 30 days to repair a device under warranty else he must provide a new one or proceed to a refund...
I was able to guide with 0.3 to 0.7 RMS during some month. It's not a settings issue...
Zwo is a good brand with great products but we need you assume a support aligned with your products prices and if you are not able to find root cause from multiple weeks, maybe a mount replacement is the good way to keep your customers.
Please could you consider this option ?
@"Tech@ZWO"

KHj89YaN

marci

Out of curiosity, is your mount an AM5N?

marci

KHj89YaN
AM5N bought begin of 2025
Same issue like others 288s periodic RA giant spikes.
No change of my settings or equipment modification before issue happened.
Mount is out of service from May/June.

uxw0xVQo

from the descriptions of the users, it seems to me the problem is kind of mechanical creep or break-in type of issue. Very much like a spontaneous back lash. That is why people experience an excellent track performance, then all of a sudden develop tracking issue in certain sectors of the astro globe. Only Zwo is qualified to identify the mechanical components that may cause such issue to prevent further deterioration to the mount reputation.

83W5rls7

@Tech@ZWO

Hello everyone.

This has happened to me too. I've had the same problem for almost four weeks. Before I file a warranty claim, I hope this will be resolved. I also contacted ZWO today to report the fault, and I'm waiting for a response.

And it was supposed to be so beautiful... :/

Marek

alastroct

A user over on CN appears to have solved this issue:

https://www.cloudynights.com/topic/959229-zwo-am5n-guiding-issues/?p=14295588

If this is in fact the issue, it implies that many more of these mounts may be affected in the future.

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