I received this small Black and White CRT monitor from a friend, Ciro Barile of TI-99 Italian User Club, this monitor was used as a video intercom and i didn’t know the power supply voltage, the pinout but especially if it worked.

Found the pinout and the power supply voltage i saw the image turned upside down, this because the monitor could be hooked both from top and from bottom, nothing could be easier it was enough to change the deflection yoke connector on the motherboard to flip the image.

I drilled two holes on the back of the case to facilitate access to the composite video input and power supply (12v 2A).

Pinout:

• RED (Video)
• GREEN (Ground)
• BLACK (Positive)
• BROWN (Ground)

Gallery:

Myarc Geneve 9640 (Replacement filter capacitors and voltage regulators).

I have replaced all the voltage regulators (7805 / 7812) of 1A with the 1.5A version and all the 22uF / 35v filter capacitors.

Will also be installed the missing heat sinks in the geneve with plastic case.

Mattel Intellivision MOD 5155 (PAL) with GSOD (Grey screen of death) Repair.

Defect:

• GSOD (Grey screen of death)

Components replaced:

• 2 x wrong resistors (who has replaced ?!?) of 150 Ohm instead of 300 Ohm.
• 1 x 74LS00 (burned because the value was wrong of the two resistors)
• 1 x RAM GTE 3539 UCP (U19)

Gallery of the repair:

Download: Mattel Intellivision Service Manual & Datasheet (908)

Irradio XTC-506R Repaired again.

It seems this small Irradio TV/Monitor always suffers from some problem, last time there were short circuits caused by the pressure of the cathode ray tube on the PCB.

This time some cold joints on the solder pads.it would have been very sad to throw it in the garbage trash.

Gallery of the work done:

Nintendo Virtual Boy Repair.

First of all, i thank Andrea Pierdomenico for this fantastic gift.

Below i explain how i have repaired the Nintendo Virtual Boy which show the classic display malfunction problems (both).

I have used only a pencil eraser and a SMD Rework Station to fix the connections of the ribbon cable to the Display PCB of the Virtual Boy.

The process involves heating the connection of ribbon cable to the Display and using a pencil eraser to push segments of the ribbon cable to the PCB.

I configured the hot air station to 145 Degrees and 55 of Air Pressure and i made 3 fast transition without ever stopping at a specific point, pressing between one pass and another with the pencil eraser.

It Works!

Gallery of the work done:

Another Gotek (HXC) with some Enhancements.

Enhancements:

• OLED Display
• Piezo Buzzer
• Push Button for select
• Rotary Encoder

Gallery:

Video:

Credits for the best firmware Jean-françois Del Nero.

Sony HITBit HB-75P (Keyboard repair).

Defect:

• Some keyboard key doesn’t work (3, MINUS, Q, SPACE, CODE [DX]).

Fix:

• Cleaning the PAD inside the Key Switch.
• Redone the soldering of the pcb pad (space switch) that was broken at the base.

Gallery:

Sony HB-F1XD (MSX2) Repair.

Defect:

• Missing Sounds.

Replaced parts:

• 3 x SMD Capacitors. (2 x 10uF – 1 x 100uF) on the Audio/Video Encoder PCB.

Gallery of the repair:

Download: Sony HB-F1XD (MSX2) Technical manual (738)

Commodore Amiga 1200 Sostiuzione Condensatori.

Gallery:

Hantarex PCB Coin-OP Monitor Full Recap.

Not very funny but someone has to do it. 8-)

Retro Things to be repaired for some friends.

• 1 x Amiga 1200 (Full Recap)
• 1 x Atari 800 XL (don’t runs anything)
• 1 x Atari 1010 (check)
• 1 x Commodore 1571 (freezed/error)
• 1 x Hantarex PCB Coin-op Monitor (Full Recap)
• 1 x Sony HITBit HB-F1XD MSX2 (missing sound)
• 1 x Sony HITBit HB-75P (keyboard problem)

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

Defect:

• Black Screen.

Replaced parts:

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

Gallery of the work done:

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.

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 (1710)

source: Cosmos Blog John Hertell Blog