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Commodore 128 (REV 310381) Repair

May 3rd, 2018 1 comment
Commodore 128 (REV 310381) Repair

Commodore 128 (REV 310381) Repair

Defect:

  • Black Screen.

Replaced parts:

  • Replaced 74LS08 (U61)
  • Replaced CPU 8502R0 (U6)
  • Replaced PLA 8721R3 (U11)

Gallery of the work done:

Pioneer LaserActive CLD-A100 – Repair & Modules full Recap

April 23rd, 2018 2 comments
Pioneer LaserActive CLD-A100 - Repair

Pioneer LaserActive CLD-A100 – Repair/Recap & Modules full Recap.

Defects:

  • The Game cartridges on the Sega Genesis Module do not work but the games on CD-ROM work correctly.
  • The INTF Ass’y Interface has some leakage capacitors and in short circuit.
  • The PSU has some leakage capacitors and in short circuit.
  • Solder joint jumped out on the three connectors that connect the two horizzonal/vertical motherboards.
  • Some cold solder on the power stage.

Works that have been done:

  • Cleaning and Full Recap PSU.
  • Cleaning and Full Recap Sega Genesis/Sega CD PAC-S10 Module.
  • Cleaning and Full Recap Nec PC Engine PAC-N1/N1 Module.
  • Cleaning and Recap INTF Ass’y Interface.
  • Rebuilding PADs of the two pcb connectors.
  • Rebuilding cold solder joint on the power stage.

Pioneer LaserActive CLD-A100 Gallery:

Sega Genesis/Sega CD PAC-S10 Module Gallery:

Nec PC Engine PAC-N1/N1 Module Gallery:

ZOE rev 2.0 Inty (Mattel Intellivision) RGB Interface

April 23rd, 2018 1 comment
ZOE rev 2.0 Inty (Mattel Intellivision) RGB Interface

ZOE rev 2.0 Inty (Mattel Intellivision) RGB Interface.

Some information about this revision:

  • The flat cable that connects the IDC 10+10 male socket to the 10+10 IDC female connector is about 15cm long (in the photo are: 20cm)
  • The cable that connects the 7 dupont connectors to the 8-pin DIN female panel socket is 30cm long (in the photo are: 20cm)
  • The video cable with a male SCART connector on one end and a 8-pin DIN male on the other side is 2 meters long.
  • The audio cable with dupont connector from one end and to solder on the other side is 20cm long.
  • The ZOE pcb must be fixed with 3 bioadhesive supports.
  • Status LED.
  • Improved audio output, there are a little less background noise.
ZOE rev 2.0 Inty (Mattel Intellivision) RGB Interface

The 8-pole DIN female panel socket can be positioned, after drilling, at any place. I recommend using the RF output hole, removing the RF modulator which is no longer usable after the modification.

This mod like the previous one works ONLY with Mattel Intellivision consoles equipped with the LM1886 (D/A Video Matrix Converter) chips. Example: PAL/SECAM but not UK/NTSC (USA). Better to check, open the console and check.

For console disassembly, desoldering the LM1886 or other connections you can consult the documentation of the previous version.

Gallery:

Soon available for sale.

Phase5 CyberStorm MK2 @ 100Mhz (040 Hack – Stable)

March 18th, 2018 2 comments
Phase5 CyberStorm MK2 @ 100Mhz (040 Hack - Stable)

Phase5 CyberStorm MK2 @ 100Mhz (040 Hack – Stable)

This is a simple hack to overclock the Cyberstorm MK2 at 100Mhz without needed adapters or simply replacing the oscillator which causes instability or malfunctions.

The hack consists downgrading the Cyberstorm MK2 to 040 simply by moving the two resistors can you see marked in the photos.

For some CPU or MK2 models it is also advisable to replacing the original voltage regulator LT1085CM at 3.3v with this one LT912CM 3.5v but if the amiga is stable after hours of operation you can also avoid the replacing the voltage regulator.

Gallery of the work done:

source: Cosmos Blog

Commodore Amiga 4000 – 64Mb Fast Memory Hack

March 18th, 2018 No comments
Commodore Amiga 4000 - 64Mb Fast Memory Hack

Commodore Amiga 4000 – 64Mb Fast Memory Hack.

The Amiga 4000 motherboard can be ´hacked´ to handle 64Mb of Fast Memory (4 SIMM modules of 16 MB each)

To do this, you have to solder a new GAL and make some bridges between FASTRAM SIMM -> GAL -> CHIP RAMSEY.

This work is not complicated but you need to have a good practice with the soldering iron and PLCC soldering.

Gallery of the work done:

Download: Amiga 4000 64Mb Hack (764)

source: Cosmos Blog John Hertell Blog

Upgrading Commodore A3640 CPU Card (part two)

March 18th, 2018 No comments
Upgrading Commodore A3640 CPU Card (part two)

Upgrading Commodore A3640 CPU Card (part two)

I have replaced the CPU 060 EC version with a 060 FULL with FPU REV 1.

When using the adapter with a non EC version of the 060 you must also use a fixed version of the kickstart v3.1 with the exec.library modified to support the FPU.

Gallery of the work done:

Download: Kickstart v3.1 Exec Patch Version for 3k & 4k - Ready to Burn! (825)

Upgrading Commodore A3640 CPU Card (part one)

March 18th, 2018 No comments
Upgrading Commodore A3640 CPU Card (part one)

Upgrading Commodore A3640 CPU Card (part one)

Works that have been done:

  • Upgrading GAL (U204 & U209)
  • Socket for Oscillator.
  • Overclocking.
  • Replacing all capacitors (the recap was already done but for the CPU adapter 040 -> 060 was necessary use smd capacitors for the little space available)
  • CPU Adapter 040 -> 060.
  • CPU Motorola 68EC060

Gallery of the work done:

Amiga 4000 repair with Floppy Drive that is not recognized

March 18th, 2018 No comments
Commodore Amiga 4000 repair with Floppy Drive that is not recognized

Commodore Amiga 4000 repair with Floppy Drive that is not recognized.

Defect:

  • Floppy Drive Dead (not recognized)

Repair:

  • Replace CIA 8520 (U300).

Gallery of the work done:

Commodore Monitor 1084S-P Repair

March 5th, 2018 No comments
Commodore 1084S-P Repair

Commodore Monitor 1084S-P Repair.

Defect:

  • Completly dead with only a loud whistling noise in background.

Repair:

  • Replaced the flyback transformer (AT2079/30102) everything has started to work perfectly.
  • It’s mandatory to made a calibration of the SCREEN and FOCUS with the two trimmer placed on the rear side of the flyback transformer.

Note:

A loud whistling noise indicates a bad flyback transformer (also known as an LOPT).

Gallery:

Download: Commodore Monitor 1084S-P Schematics (370)

Commodore CBM 8032 – Motherboard Repair (ASSY 8032030)

February 11th, 2018 No comments
Commodore CBM 8032 (HP Early version [1980]) Motherboard Repair (ASSY 8032030)

Commodore CBM 8032 (HP Early version [1980]) Motherboard Repair (ASSY 8032030)

Defect:

  • Garbage screen.

Repair:

  • Replaced 4 x 2114 Static RAM (UC4 / UC5 / UC6 / UC7)

Note:

As you can see from the photos this computer is already been repaired by a butcher. The butcher did not use the sockets after replacing the static ram ones and the pads had already suffered from the previous desoldering and soldering, probably using an unsuitable soldering station.

Gallery of the repair:

 

Commodore CBM 8032 – PCB Monitor Repair (ASSY 321448)

February 11th, 2018 No comments
Commodore CBM 8032 (HP Early version [1980]) PCB Monitor Repair (ASSY 321448)

Commodore CBM 8032 (HP Early version [1980]) PCB Monitor Repair (ASSY 321448)

Defect:

  • Dead. Missing High Voltage from Flyback Transformer (LOPT)

Repair:

  • Replaced 2 x burned resistors of 56Ohm 1/4w (R752 / R753)

… and now let’s move on to the second defect. :-)

Gallery of the repair:

 

GIG Leonardo Composite Mod

January 16th, 2018 No comments
GIG Leonardo Composite Mod

Video Composite modding:

  • Removed the RF modulator.
  • Removed one pin of the 3 resistors (see photo) for the video composite output, you can get a better image (contrast and color) (see photo)
  • I have used the same hole of the RF cable for the composite video and audio cable.

Gallery of the Video Composite mod:

 

Sega Game Gear (Boxed) Full Recap

January 1st, 2018 No comments
Sega Game Gear (Boxed) Full Recap

Sega Game Gear (Boxed) Full Recap.

Defect:

  • Dead but the Power LED is turned ON.

Repair:

  • Replaced all capacitors (Main / DC-DC / Audio)

Gallery of the repair:

Commodore 64C (ASSY 250425) Repair

January 1st, 2018 No comments
Commodore 64C (ASSY 250425) Repair

Commodore 64C (ASSY 250425) Repair.

Defect:

  • Basic Screen without text and prompt.

Replaced parts:

  • 1 x MT 4264-20 RAM (U24)

Gallery of the repair:

 

Texas Instruments TI-99-4A Repair

January 1st, 2018 No comments
Texas Instruments TI-99-4A Repair

Texas Instruments TI-99/4A Repair.

Defect:

  • Cartridges port doesn’t work.

Fix:

  • Cleaning the cartridge connector (computer side) with one pin oxided.

Gallery of the repair: