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Commodore Amiga 1200 Full Recap & Cleaning Floppy Drive

May 12th, 2018 No comments
Commodore Amiga 1200 Full Recap & Cleaning Floppy Drive

Commodore Amiga 1200 Full Recap & Cleaning Floppy Drive.

Gallery:

Restoration and Repair Commodore Floppy Drive VC-1541

May 5th, 2018 2 comments
Commodore Floppy Drive VC-1541 (differences before and after)

I start immediately to say; Floppy Drive, Metal base with the Transformer are ended up in the trash, are unrecoverable (see photo).

What i did is carefully clean the external case of the Floppy Drive which i am quite satisfied of the result.

Then i have started to repair and carefully clean the motherboard of the Floppy Drive (REV 1540050) that had the following problems (see photo):

  • I had to use the sockets for all the integrated circuits, because the rust had crept under all the integrated circuits, creating many problems.
  • Remove the voltage regulators and clean the rust that was under the heatsink.
  • Clean and try all integrated circuits after removing them.
  • Clean the PCB.
  • Replaced 2 x 6522 (VIA) that is not working.
  • Replaced 1 x 6502 (CPU) that is not working.
  • Replaced 1 x HM6116P (STATIC RAM) that is not working.
  • Replaced 2 x Resistors of 9.1k 1% interrupted.
  • Replaced for safety also 1 x Resistor of 91ohm 1%.
  • Moved the ceramic capacitor (FIX by Commodore) to the solder side, which was fixed above the 74LS86.
Restoration and Repair Commodore Floppy Drive VC-1541

What i have used to clean the external Floppy Drive case:

  • I have used a plenty of running water by rubbing with a brush to remove everything you could do without using specific products.
  • I have used CIF GEL with bleach that i left to act for 30 minutes.
  • I have rinse thoroughly with water, always rubbing with the brush and with a stanley plastic spatulas
  • I repeated these last two phase for least 3 times.
  • I have used CIF Degreaser with Bicarbonate that i left to act for 10 minutes.
  • With a Brush / Toothbrush / Toothpicks / Cotton Fioc / Stanley plastic spatulas o have rubbed and cleaned the most dirty and hidden parts.
  • I have rinse thoroughly with water, always rubbing with a brush.
  • I repeated these last three phases for least 4 times.
  • I have completed the cleaning with the Glassex and Alcohol.

I have used a Floppy Drive mechanics and a transformer that i have found in the laboratory that i have installed in the Floppy Drive VC-1541 case.

Restoration and Repair Gallery:

Differences before and after the restoration Gallery:

Commodore VIC-20 (ASSY 250403) Repair

Commodore VIC-20 (ASSY 250403) Repair

Commodore VIC-20 (ASSY 250403) Repair

Defect:

  • Black Screen.

Replaced parts:

  • Replaced MOS 65245 [74LS245] (UF8)

Gallery of the work done:

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 No 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 No comments
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 No 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 (534)

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! (611)

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 (167)

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: