Megatouch XL Repair Logs
Unit had no power supply, but takes a standard 200 to 250 watt mini-tower AT style power supply - NOT an ATX style. The standard rocker switch from an old AT mini-tower fits into the cutout for the power switch on the back panel.
NOTE: Be sure to use one with an auxiliary power connector so the monitor can be plugged into the back of the supply for 110v power.
TIP: Power supply
An ATX power supply CAN be used with an appropriate ATX to AT power connection adapter. Just beware that it will require some rewiring of the unit since the monitor plugs into the auxiliary power connection on the back of the power supply and most ATX power supplies do not have this. Also, the power switch will require rewiring since ATX supplies do not have a hard AC power switch coming off of a 4 wire cable as the AT style does.
If the power switch is missing, a Philmore model no: 30-16564 switch will fit perfectly in the hole. When inserting it, the switch lugs are oriented downward. In other words, the blank part of the back of the switch is facing upwards. This will align the switch so that the up position is for power on.
According to the Philmore datasheets, the switch model 30-16625, which is labeled on/off, has the same size/shape and should fit as well.
Symptom: Locks up
The cache tag RAM was bad. Replaced the tag RAM and tested.
NOTE: Tag RAMs must be replaced with one of the same speed OR faster. These are rated as 12ns, NOT 120ns. 15ns WILL NOT work and will cause more lockup problems.
These chips can be tested as standard SRAM ICs in most testers. 8K x 8 SRAMs can be tested as a 6264 standard style SRAM. 32k x 8 can be tested as a 62256 SRAM. Just beware that this will only find hard errors on the chip. Errors that only show up at high speeds will not be found this way and will only be found by substitution.
Symptom: License error
Board gave a license error message, but had the correct license chip for the version of game on the hard drive.
Cleaned the contacts on the riser card and the I/O board with a pink pencil eraser. Nothing. The I/O board was covered with years of cigarette tar. Cleaned the board with hot water and Formula 409 Orange then dried it at 170 degrees in the oven. Cleaned the Dallas security button chip socket and the 5 pin connector (CAREFULLY) with a pink eraser. Reassembled game and had lots of fun testing.