From the face of it, suspect line flyback pulse or pulse field is not fed to the CPU. First check the 27-pin voltage is normal. Then measured 35 feet voltage is 5V (exactly equal to the supply voltage of the CPU), indicating 35 feet without field pulse input. Charles 35 feet peripheral circuits found Q1160 circuit, replacement, troubleshooting. Note that, if the transistor can not find the original model can also be used to replace C1815.6Zhservice manual download site