BackgroundSometime in the late 90's my wife purchased an fifteen needle automated embroidery machine. Specifically a SWF A/1501. For those not familiar this type machine here is a link to a similar machine in action SWF B/1501. This is later model of the same machine, it has similar control panel. About 8 or 9 years ago the machine required that the operating system be reload each time the machine was started and any saved patterns were lost. Eventually the operating system would not load and the machine would just sit with "SYSTEM LOADING" displaying on the LCD screen.
Some research on the internet allow us to determine that the embroidery machine utilized a embedded computer control system based on a processor similar to the Intel 80386. The computer is a SBC (Single Board Computer). The system as shipped included a 3 1/2" HD floppy drive, two serial ports and one parallel ports for input. For storage rather then a hard drive the SBC included a DishOnChip 2000 by M-System.
|SBC from SWF Control Panel|
Replacing the DishOnChip cured the problem, at the same time we purchased a floppy drive to USB drive upgrade. See PLR Electrionics for more information. While it was great this resolved the problem we still in the dark about how to repair the control panel.
Once again the machine stopped loading the operating system. Replacing the DishOnChip did not resolve the issue. Attempting to troubleshoot the problem was futile. We purchased a ISA backplane board see Advantech passive backplane board for more information. Tied to standard AT power supply and an ISA VGA card we were able to boot the computer but it would not display any information on the screen. It was determined that to accommodate the LED and LCD screens on the control panel the BIOS had been modified.
The simple solution was to purchase another SBC, a review of the parts book that accompanied the machine indicated that the part is number 02-100A-AT01, CPU CARD (ROCKY-386) ASS'Y. A review on the internet lead us to Penn Sew. There had to be another way. The description ROCKY-386 is miss leading there was a SBC labeled ROCKY-318 but it has a completely different form factor. Same processor, the PC104 socket is in a different location nor does it have the inline keyboard socket that the original card has.
All attempts to load DOS via 3 1/2" floppy drive were successful but the output viewed on the LED screen was limited and no information was available mapping of the keys on the control panel so it was not possible to enter any commands. We found and purchased another SBC with a similar form factor. The existing SBC had both ISA and PC104 bus systems, the PC104 is utilized in the control panel. The standard BIOS on the new SBC could communicate with the VGA card but NOT the the LED and LCD screens on the control panel. What we needed was another SBC of the same type with a standard BIOS. We finally found one we could afford in China.
Dis-assembly and repair of the SBC
|SWF Control Panel|
The back of the SWF control panel has four Phillips head screws and three thumb head screws. To begin the dis-assembly loosen and remove the three thumb screws. Note the two sections are hinged together.
|Back of SWF Control Panel|
|SWF Control Panel hinged open|
|Back of SWF Control Panel on the bench|
|I/O Board ready to be removed|
|Back of I/O board note the PC104 connector|
|SBC after the I/O board is removed|
|SBC on the bench|