Phil, I put your entire post into chatgpt, and got a long answer. This might be an approach to help you.
The combination of `SER ERR`, intermittent `ENCODR` errors, and occasional positioning followed by a `HI-POWER` error makes me suspicious of an encoder feedback problem, but I wouldn't condemn the encoder just yet. On these older Haas indexers, the encoder, its wiring/connectors, the motor, and the servo control electronics can produce overlapping symptoms.
The good news is that Haas's older HA5C documentation specifically identifies `Ser Err` as excessive servo following error and `EncodEr`/`EncodES` as encoder Z-channel faults or missing signals. The troubleshooting guide lists a bad encoder or cable as possible causes. 2003
+1
Since yours is the red control box with the 17-pin connector, I'd approach it as an older-generation unit and avoid assuming the diagnostic procedures for newer Haas rotary systems apply.
## What I'd check first
1. Check the connector itself, not just cable continuity. Inspect the 17-pin plug and receptacle for recessed or loose contacts, corrosion, oil, damaged shielding, and poor strain relief. A cable can pass a continuity test and still fail when flexed or when a contact is carrying a signal.
2. Test with the indexer unloaded. With power off, disconnect any workholding or load you can safely remove. Check whether the spindle rotates smoothly by hand, without tight spots or binding. Don't force it against the worm drive.
3. Watch what happens when the fault occurs. Does the displayed position count or update correctly immediately before the error, or does it freeze/jump? If it tracks position and then loses it, that helps distinguish intermittent feedback from a drive or mechanical problem.
4. Don't overlook the motor. A binding mechanism or motor fault can cause a following error even if the encoder is healthy. A `HI-POWER` indication alone doesn't prove the encoder is at fault.
Haas's [HA5C operator's manual](<https://service.haas...h_June_2006.pdf>) is a useful reference for the older control's error codes and troubleshooting. Haas CNC
+1
## How to separate the encoder from the control box
The most useful test is a known-good substitution test, if you can borrow compatible equipment.
- Try your indexer on a known-good compatible red control. If it runs correctly, your original control becomes the prime suspect.
- Try a known-good compatible indexer on your red control. If that unit develops the same errors, suspect the control or its encoder input circuitry.
- If both combinations fail intermittently, investigate the cable, connectors, and compatibility before drawing conclusions.
Make sure the substitute is compatible with your exact motor generation and control. Don't plug in an arbitrary encoder or motor just because the connector fits.
A multimeter continuity test alone cannot verify encoder pulse quality or signal integrity. Properly testing the encoder may require an oscilloscope or suitable encoder tester, plus the correct pinout and signal specifications for that particular motor.
## Can the encoder be removed and cleaned?
I wouldn't try to pull the encoder out of the motor until you've identified the motor and encoder assembly. On some older servo motors, the feedback device is mounted at the rear of the motor and can be serviced; on others, access requires disassembly and careful alignment. There isn't enough information from the red box and 17-pin connector alone to identify the exact construction.
If you open the assembly, disconnect all power first and follow the applicable service instructions. Avoid spraying contact cleaner into the encoder or disturbing its alignment.
## A few details that would help narrow this down
Could you tell me these two things?
1. Is the indexer itself a HA5C 5C-collet indexer, or an HRT rotary table?
2. When you say `HI-POWER`, is that the exact message on the red control's display, or is it a fault shown on the machine's CNC control?
A photo of the red control's front panel and the motor end of the indexer would be especially helpful. With those details, I can help narrow down the likely encoder type, whether it is externally accessible, and the safest way to test the control independently.
