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PB 160 issue
- Thread starter JRL
- Start date
Does the fault rectify itself after a time, whether that is spent active or asleep? Can it be rectified by adjustment of the brightness and contrast sliders, even if it reappears later? VRAM malfunction is a possible cause, but so is slider malfunction, a faulty inverter board or connections, and other causes too arcane to guess at. Before you have the PB apart, and have cleaned inside, and have undone and then remade all the internal connectors (to ensure their electrical continuity), speculation is just that. Try to eliminate conventional causes of malfunction, and then those that remain, if any, may be true hardware faults that need to be addressed. You are attending what is, by any reckoning, an elderly computer that has every justification for a few aches and pains.
de
de
I'm somewhat confused. Your comment suggests that the QT version was the correct one, then.
I worry that your problems may not be over. For instance, if you have an intermittent display cable, simply fiddling with your computer could've fixed things for a time, with none of it due to QT. If the problem should recur, you may want to take a look at the cable (a known source of problems similar to the one you originally reported).
tomlee59 saith sooth. The logic-board-to-display cable is stiff, as you know, and has to be 'crinkled' to allow the case halves to be separated for connection/disconnection of the cable while yet being able to compress out of the way when the halves are re-assembled. Its ageing plastic and the wires together make it stiff and give it a spring-like 'memory' of its usual functioning shape, which can be enough to pull it from its mating upper connector even as the PB is reassembled, especially if you have given it an extra 'crinkle' during your handling of it. This alone could be responsible for the display horrors, and is part of the reason for ensuring the integrity of all internal connectors.
If you have had the inverter board out, it needs special care to ensure, at reassembly, that the slider buttons for brightness and contrast are mating correctly with the linear control potentiometers on the inverter board. Check also that some wag has not replaced the blue 350VAC inverter board for a passive FSTN display with a green 400VAC board for an active TFT display (from a PB 180). The correct boards are 922-0025 (160) and 922-0024 (180), which are easily confused if one is colour-blind. Another possibility is a mismatched display from a PB 180, swapped in without consideration of the higher inverter voltage needed for the TFT display. Does your display exhibit the 'submarining' characteristic of an FSTN display when you move the pointer?
de
If you have had the inverter board out, it needs special care to ensure, at reassembly, that the slider buttons for brightness and contrast are mating correctly with the linear control potentiometers on the inverter board. Check also that some wag has not replaced the blue 350VAC inverter board for a passive FSTN display with a green 400VAC board for an active TFT display (from a PB 180). The correct boards are 922-0025 (160) and 922-0024 (180), which are easily confused if one is colour-blind. Another possibility is a mismatched display from a PB 180, swapped in without consideration of the higher inverter voltage needed for the TFT display. Does your display exhibit the 'submarining' characteristic of an FSTN display when you move the pointer?
de
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