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Commodore Amiga 4000 Repair – System Clock Dead

February 23rd, 2016 1 comment
Commodore Amiga 4000 Repair - System Clock Dead

This post is dedicated to all the people that do not remove the damn battery on any hardware, not only Amiga.

It was better don’t make this repair, i knew from the beginning, when you find an acid lake that takes away everything, pad, pcb tracks and some welding is better left alone, however the Amiga 4000 was working perfectly but without the a way to Save or Load the system Date.

I wanted to challenge for the umpteenth time this problem where anything that i make comes off and worsens the situation already dramatic.

Conscious that the final work was a colossal shit, because with exploded pad, broken track and the through holes between layers fucked up you can not do miracles, you can only hope doing your best.

In fact, it works perfectly, but it remains a shitty job, unwatchable.

Moral: REMOVE ALWAYS THE BATTERIES and if the pcb is corroded by the leaked acid clean very well using appropriate products, not with the usual alcohol or a bath with soap, used products like PCC KONTAKT CLEANER or like, scratching well the pcb and also the holes between layers using a needle fine.

Gallery of the repair:

Amiga 4000 Repair – Joystick on port #2 always goes in one direction

February 23rd, 2016 No comments
Commodore Amiga 4000 - Joystick on port #2 always goes in one direction

Defect:

  • The joystick on port #2 always goes in one direction (left).

Repair:

  • Replaced the two 74HCT166 (SMD) that control the logic of both joystick ports have been eaten by the acid leaked from the battery and a cause of a short circuit both are dead. (please see photos)

Gallery of the repair:

Commodore Amiga 1200 Full Recap

February 23rd, 2016 No comments
Commodore Amiga 1200 Full Recap

Commodore Amiga 1200 Full Recap.

Commodore Amiga 3000 REV 8.9 (B2) Full Recap

February 23rd, 2016 No comments
Commodore Amiga 3000 REV 8.9 (B2) Full Recap

Commodore Amiga 3000 REV 8.9 (B2) Full Recap.

Restoring the original configuration of a ACT Elek. Apollo 1260

February 23rd, 2016 3 comments
Restoring the original configuration of a ACT Elek. Apollo 1260

Restoring the original configuration of a ACT Elek. Apollo 1260

Works that have been made:

  • Cleaning the pad and weld residues on the solder side of the 68060 CPU.
  • Removing the KIT/Hack to use a SIMM 64MB instead of 32MB. The KIT / Hack not working well.
  • Restoration of the power PCB of the CPU and installation of the BD242 transistor (TIP32) in place of a voltage regulator. (Now the PCB is in original state)
  • Someone needs to explain me how the fuck do you can use a voltage regulator type LT1085(84) fixed 3.3V instead of a Transistor!
  • Overclocking with 80MHz oscillator.

Gallery:

Commodore Amiga CD32 Full Recap

February 23rd, 2016 No comments
Commodore Amiga CD32 Full Recap

Commodore Amiga CD32 Full Recap.

Gallery of the repair:

Commodore 128 Garbage Screen & Random Memory Problem repair

February 23rd, 2016 1 comment
Commodore 128 Garbage Screen & Random Memory Problem repair

Commodore 128 Garbage Screen & Random Memory Problem repair

Defect:

  • Garbage Screen in 128 mode and Random Memory problems in 64 mode.

Repair:

  • Replaced the MOS 8502 CPU.

Note:

  • The problem of the Garbage Screen / Out of Memory / Memory problems of the Commodore 128 is not always a problem of Ram / Multiplexer or Bank Switching.

Gallery of the repair:

Texas Instruments Floppy Disk Controller ROM (EPROM) upgrade

February 23rd, 2016 No comments
Texas Instruments Floppy Disk Controller ROM (EPROM) upgrade

This upgrade kit for the standard TI disk controller card allows 80 track drives to be used, such as a 3 1/2″ 80 track floppy.

The modified code supports 40 and 80 tracks for SSSD and 80 tracks for DSSD, whatever drive is designated as the 40 track drive, either #1 or #3, supports 40 track DSDD.

The update is very simple to make, you have to remove the original ROMS and replace with two sockets and insert the two 2532 EPROMS pre-programmed.

Gallery:

Download: FDC Latest ROMS (800)

Commodore Amiga 2000 PSU Upgrade

February 16th, 2016 6 comments
Commodore Amiga 2000 PSU Upgrade

Commodore Amiga 2000 PSU Upgrade.

I have replaced the PCB of the Commodore Amiga 2000 power supply because tired and died after many years of use and there was not the slightest sense of the repair.

The difficulty to the present day is finding a power supply ATX v1.0 with -5v (white wire) in the later versions of ATX PSU was removed, the Amiga 2000 uses this voltage for the ZORRO cards.

*UPDATE*

If you have trouble to finding an ATX power supply with the -5v output (white wire on the connector) you could use a voltage regulator LM 7905 to adjust the voltage from -12v (available in all ATX power supplies also of the latest generation) to -5v.

Due to the missing TICK signal you need to move the jumper J300 to the position 2-3 and if you have an Amiga 2000 REV4x you need to move the jumper J34 to the position 2-3.

Below the work was done.

Gallery:

source: John “Chucky” Hertell Blog

Commodore Amiga 4000 PSU Upgrade

February 15th, 2016 3 comments
Commodore Amiga 4000 PSU Upgrade

Some months ago i have decided to upgrade the power supply of my Commodore Amiga 4000 with a good ATX power supply, compact and with a high amperage.

I have found the SFX POWER 2 300w from the German Company: Be Quiet. The power supply is perfectly suited to my needs.

Below the work was done, anything of complex if not fit the PCB inside the power supply of the Commodore Amiga 4000.

Gallery:

Easy trick to improve a little bit the video quality for the C64

January 29th, 2016 3 comments
Cut the resistor

Easy trick to improve a little bit the video quality for the Commodore 64.

The fix can be made without removing the modulator. Obviously the RF output doesn’t work anymore.

Gallery:

Vogatek A51099 Arcade Supergun Controller Firmware Upgrade

January 25th, 2016 No comments
Vogatek A51099 Arcade Supergun Controller Firmware Upgrade

Hex file for upgrade/mod the Vogatek A51099 Arcade Supergun 16F505 controller chips by MCJ Design 2007

Installation instruction:

  • Simply program the hex file onto 2 * Microchip PIC16F505 chips.

Features:

  • Press “A” on Megadrive/Genisis controller on the first power-up (this fixes random key outputs if the 2nd Controller is not used).
  • PCB mod (detailed photo in the archive). Press Start + C to add coin/credit.

Gallery of the firmware upgrade:

Download: Hex file for upgrade/mod the Vogatek A51099 (883)

Repair Sinclair Spectrum +3 Power Supply

January 25th, 2016 No comments
Repair Sinclair Spectrum +3 Power Supply

Repair Sinclair Spectrum +3 Power Supply

Defect:

  • Dead.

Problems:

  • All pad of the transformer output are broken.
  • Broke the fuse holder and therefore the fuse it moves inside the power supply.

Repair:

  • I have made bridges to restore the connection between the pcb and the transformer.
  • Replaced the fuse holder.

Gallery of the repair:

The Macintosh Recap Day

January 25th, 2016 No comments
The Macintosh Recap Day

Someone has to do this tedious job and also i advise you do not postpone the capacitors replacement.

Macintosh Recap:

  • 1 x Macintosh Portable
  • 1 x Macintosh SE (battery removed)
  • 1 x Macintosh LC520
  • 1 x Macintosh Color Classic

Gallery of the Macintosh Recap:

Repairing Radio Shack TRS-80 Model 1 ..for the third time

January 25th, 2016 2 comments
Repairing Radio Shack TRS-80 Model 1 ..for the third time

Repairing Radio Shack TRS-80 Model 1 ..for the third time

Defect:

  • SHIFT keyboard switch broken.
  • Garbage Screen on boot (already repaired).
  • Flat cable of the Keyboard broken (already repaired)

Repair:

  • Replaced the keyboard switch with a new one taken from a keyboard (the good one) of the Texas Instruments TI-99/4A that helps me many times.
  • Replaced a 2102 Video SRAM.
  • Rebuilt the keyboard flat cable.

Gallery of he repair: