1. system display breakdown 1.1 breakdown 1: system display screen automatically resets
| breakdown causes | solutions |
| long operating time for machine tool causes system overheat and reset chip damaged or unstable | change reset chip or mainboard 928 tc into 809ic and 980t into 810tc |
1.2 breakdown 2: display screen blue screen
| breakdown causes | solutions |
| frequent blue screen, display circuit or ic components breakdown | change mainboard |
| occasional blue screen caused by system overheat or endless loop program | shut down the system and reboot it |
| contrast brightness on display screen is not set up | read instruction and adjust brightness |
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1.3 breakdown 3: messy code on display screen
| breakdown causes | solutions |
| internal breakdown of system mainboard or bad connection of internal contactor | change mainboard or send it to the manufacturer for maintenance. if internal conncetor are badly connected, then open the system and reconnect all contactors |
1.4 breakdown 4: no display in system
| breakdown causes | solutions |
| input voltage anomaly makes it impossible for the system to get normal voltage | check 220v voltage input contactor in system, see if 220v voltage is normally run. if so, check if all components of the power supply circuit is damaged, all contactors are connected well and external voltage is stable |
| power pack breakdown, no voltage output in power pack | check if 5v, 12v, 24v, -12v in power pack is normal. if not, the power pack should be sent to the manufacturer for maintenance |
| short circuit among system internal components leads to abnormal voltage | send to the manufacturer for maintenance |
| caused by external loop, suspension line and other situations leading to short circuit | check external connection or thread encoder, check whether to lower 5v voltage, check the circuit insulativity against machine tool, check if there is water damage and feeding breakdown in encoder contactor |
| bad circuit connection on internal display screen | open system cap, reconnect the contactor tightly |
1.5 breakdown 5: crash
| breakdown causes | solutions |
| crash caused by 928tc program (v2.13 v2.23) | press enter key and reset key at the same time, power on; release reset key first, then release enter key after a while; input m8000, press enter key, press “0, enter”; input “0, enter” for six to eight times; enter program zone, delete extra programs to release space |
| crash caused by filled 928tc program | press enter key and reset key at the same time, power on; release reset key first, then release enter key after a while; press 0, 1, 2, 3, 4, enter; input m8000, press enter key, press 1, press spindle high and low end shift key, enter; press “0, enter”; note: this operation will delete all programs to release space, please make backups |
| external input output line, external loo[ start button and other situations leading to short circuit make the system crash down | check circuit, exclude short circuit, change all components that causes short circuit |
2.system breakdown
2.1 breakdown 1: system breakdown
| breakdown causes | solutions |
| system display of “emergency stop alarm”is caused by non-reset of emergency stop button, limit and broken circuit | check if the emergency stop button is reset, if limit switch is broken or broken circuit disables emergency stop, if there is short circuit or bad connection; if reverse diode connection burns 2803ic and makes 24v signal output ineffective. change 2803ic |
| unstable voltage leads to driver or frequency converter alarm and further triggers system alarm | check power supply voltage, install voltage stabilizer |
| system display of “driver not ready”alarm | no power supply for the driver, check if there is broken power supply circuit, if all components are damaged; improper setting of drive parameter, modify the following parameters: 9 for 980t, 12 for 928tc, 10 for 928ta; check drivers by exchanging them |
| program operating alarm during system programming results from illegal editing or misoperation | read the appendix of system operating instruction or lathe system alarm, find out corresponding solutions based on system alarm |
| serial alarm or chinese alarm results from wrong parameter setting or illegal editing | read the appendix of system operating instruction or lathe system alarm, find out corresponding solutions based on system alarm |
| 980t alarm | 980t alarm, open system cap, reconnect gate array tightly; if it still doesn’t work, send it to the manufacturer for maintenance. 900m alarm. modulate 5v output voltage in power pack. if it still doesn’t work, send it to the manufacturer for maintenance. |
2.2 breakdown 2: “driver alarm” on 928tc but the driver doesn’t give an alarm
| breakdown causes | solutions |
| allm circuit failure inside the driver | disconnect alarm circuit on the driver and the system or send it to the manufacturer for maintenance |
| while executing arc machine program, because the machined arc passes quadrant, the system crashes, causing false alarm | initialize the system, modify machine program, avoid arc passing quadrant |
2.3 breakdown 3: “err-20” alarm in 991 system while the driver runs normally
| breakdown causes | solutions |
| there is a triode between the first and tenth pin of system signal line. this triode conducts when receiving external interference and turns the first pin into low level and causes system alarm | check if there is a triode inside signal line plug. if so, cancel this triode |
3.instruction control fault
3.1 breakdown 1: 928tc g0 instruction positioning
| breakdown causes | solutions |
| single axis positioning at the first paragraph of the program causes wrong lathe motion | two axes simultaneous positioning for the first paragraph of the program, the same as the first paragram after changing the tool. otherwise, it may causes wrong motion. g01 cannot be used in the first paragraph of the program but g00 can. this programming method is decided by system software and needs improvement |
3.2 breakdown 2: any program segment starting may cause wrong motion
| breakdown causes | solutions |
| start from one program segment, when the program ends, restarting clamping workpiece (start from the program heading) causes wrong operation, x and z moves greatly at g00 speed towards positive direction | this programming method is decided by system software and needs improvement |
3.3 breakdown 3: the machining direction under constant linear speed control cannot be changed
| breakdown causes | solutions |
| no frequency converter for the spindle | use the spindle with frequency converter, make sure the correct operation of frequency converter |
| select correct instruction and adjust parameter | make sure the feed instruction is based on per minute instead of per revolution, adjust constant linear speed |
| the control of constant linear speed, when the tool moves from negative direction of x axis towards positive direction | the tool must move from positive direction of x axis towards negative position during programming, which is decided by the programming format of system software |