Commodore Amiga 500 Keyboards Join & Fix.

Unfortunately from five keyboards i have made only one in a good shape and full working.

Commodore Amiga 500/600 PSU Repair

Amiga 500/600 (PSU) PowerSupply #1

Defect:

• Short-circuit and the fuse blows.

Replace parts:

• 1 x Transistor NPN 2SC3679.

Amiga 500/600 (PSU) PowerSupply #2

Defect:

• Short-circuit and the fuse blows.

Replace parts:

• 1 x Transistor NPN BU508A.

Amiga 500/600 (PSU) PowerSupply #3

Defect:

• Short-circuit and the fuse blows.
• The PCB is half broken.
• Some components have suffered of too much heat.
• The locking pins of the cover are broken.
• Dirty and Yellowed.

I don’t made the repair. I recovered what might come in handy.

Gallery:

The Gotek is a USB Floppy Drive emulator very cheap, you can buy it from eBay at €24.00 €20.00 including the shipping cost.

Let’s start by saying that this Floppy Disk Emulator with the original firmware is totally useless for our purpose, like to connect it to an Amiga and in the near future to a Atari ST or Amstrad CPC. The new firmware written by Herve Messinger replaces the original firmware, to do this you need a simple converter from USB to TTL Serial Interface to program the STM32 ARM Cortex MCU.

I would add this thing; this Floppy Drive Emulator is not absolutely comparable to the HXC Floppy Emulator of Jean-François DEL NERO (Jeff) where in addition to supporting dozens of Floppy Formats/Hardware and the Firmware is in development from several years but it’s a nice and inexpensive alternative.

For more information, firmware and programming tool you need to go here the official blog of Herve Messinger.

Video:

source: cortexamigafloppydrive.wordpress.com

Gallery:

Commodore SX64 Keyboard Fixed.

Defect:

• Some keys works and some not.

Work done:

• Cleaning with a “Contact Cleaner” to remove the oxidation of gold contacts under the membrane.
• Cleaning all keys.
• Cleaning the keyboard case (inside/outside).

Gallery:

Replacement NiCd Battery of a Commodore SR4190R Calculator.

Defect:

• Battery Leaks.

Replaced parts:

• Replaced 3 x NiCd Rechargeable Batteries 1.2v.

Gallery:

Commodore SX64 (USA/NTSC) Repair.

Defect:

• Black screen and then noise of a misaligned drive (don’t read anything).

Replaced parts:

• Replaced 1 x 906114 PLA (UE4)

Other things:

• Aligned the Floppy Drive using the original copy of the Free Spirit Software Drive Alignment.
• Removed the broken switch to disable the write protection and disconnected a LED on the front side of the SX64.
• Connected the sensor wires cut.
• Cleaning the Floppy Drive.

Apple IIc Rom v4 Upgrade & Repair.

Defect:

• The second RAM in the auxiliary memory is faulty.

Replaced parts:

• Replaced 1 x RAM 4264 (ARD1)

Upgrade:

• Apple IIc ROM upgraded to the latest version V4 (MON)

Download:

• Apple IIc v4 ROM + Installation Manual (1666)

Commodore CBM/PET 3032 Motherboard Repair.

Defect:

• Garbled screen and then “Illegal Quantity Error” message or 31 Bytes free

Replaced parts:

• Replaced 1 x NE555 (A2)
• Replaced 2 x Unstable RAM 4116 (I2/I3)
• Replaced 1 x 74LS153 (E4)

Atari Disk Drive 1050 #1

Defect:

• SIO bus unresponsive.

Replaced parts:

• Replaced 1 x LM3086N (U1)

Atari Disk Drive 1050 #2

Defect:

• SIO bus unresponsive + no reset cycle of the Disk drive on poweron.

Replaced parts:

• Replaced 1 x RAM-I/O-Timer (RIOT) 6532 (U7)

Gallery:

Commodore 64 ASSY 250407 Empty PCB + some Working components.

The horizontal measuring was made calculating the ledge at the base of the monitor.

Unfortunately, this monitor suffers from a serious problem of image quality.

The monitor become very hot and the adjustment resistance (trimmer) of the Focus controls that is inside the flyback loses its original value.

After nearly an hour of operation, the image becomes blurred and we must adjust the trimmer of the focus located inside the monitor, that’s why i have made this modification to the external case of the monitor.

The flyback is NOT longer exists as a spare parts.

Datanetics Apple Keyboard Fix.

After a few cold solder joints redone the keyboard works almost perfectly.

Todo:

• The “V” key is totally dead.
• The keys are a bit tired, don’t return always in the original position.

Overall is fine.

Datanetics Apple Keyboard *update*

I found a temporary solution for the tired keys they don’t return always in the original position. I have put a small spring (see the picture). Now the keys works correctly.

About the “V” key completely dead, i have desoldered it and i have tried to spray a air into the slots without having any results, so i have tried a extreme thing, i have used the key switch like a whistle. ;-D I have blown inside several times, the result is the key switch now are working again. I have made the same thing for the “right arrow”.

Macintosh Plus repair.

Defect:

• Mac sad face with error code not readable.

Replaced parts:

• 2 x ROM (342-0341-B / 342-0342-A) replaced with two EPROM 27C512 (pinout compatible)

Note:

All roms that i have found on the net or sent by friends are not working.
I had to do a dump of the Rom of my Macintosh Plus and at this point everything has worked immediately.

Download: Macintosh Plus ROM (27C512 Splitted) (1591)

Apple IIe STK Asic Clone (Maybe Orange) repair.

Defect:

• Short-circuit on all voltages.
• Black/Garbage screen.

Replaced parts:

• 10 x Tantalum Capacitor 4.7uf (replaced with Electrolytic Capacitors)
• 3 x RAM OKI M3764A-15 in Short-circuit.
• 1 x ROM 1 (EPROM 27128)

Note:

I have to thank immensely my friend Alessandro Polito for providing me the dump of the ROM 1 of the Orange (Apple IIe Asic Clone)

Download:

• Orange Apple IIe Clone Roms (1561)
• Orange Apple IIe Clone (Roms1 now is Correct) (436)

Gallery:

Commodore 64 ASSY 250425 Empty PCB + some Working components.