| Electronics > Repair |
| LCD wrong viewing angle Sony Walkman |
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| dredd:
Unsoldered CB701 and of couse it measures right :) 110, 110, 110 and 95nF Now Im shopping for microscope to put it back. What are the good ones? AmScope double boom arm costs a kidney. EDIT: Ordered AmScope SE400-Z, $450, cancelled it and got noname stereo one, used from eBay. It has 10xWF eyepieces and 2x and 4x detachable objectives. I need to find 0.5x or 0.75x barlow lens to replace the 2x one. |
| dredd:
--- Quote from: Haenk on May 24, 2024, 06:58:27 am ---Before dissecting the machine, did you try with another polarizer? The foils can fail (due to UV light, aka sunlight, but maybe even just age). Any polarizer (that is not circular) will do, maybe rip it off another LCD display. --- End quote --- Well, now I can use hot air and solder paste, new superpower :). I soldered new CB701 back, no change. Bought polarizer film, removed top polarizer, it was glued on. Tried new one - no change. Not a proper test, I did not cut the sheet and was just rotating it above display. There is bottom polarizer too, I suspect, together with mirror foil, Im debating should I remove it too, because the voltages on IC702 were not right, polarizer might not be the reason. |
| jzx:
Have you checked C710 and C711? Check with the scope, they posibily are part of a voltage pump. |
| dredd:
--- Quote from: jzx on May 31, 2024, 01:41:17 pm ---Have you checked C710 and C711? Check with the scope, they posibily are part of a voltage pump. --- End quote --- C710 = 0.13 uF (0.1uF in specs) C711 = 0.14 uF (0.1uF in specs) both are kinda OK. Whats not OK is voltages on them. IC702: pin 41 = +0.78V (+1V on diagram) pin 42 = -0.24V (0V on diagram) pin 43 = -1.25V (-1V on diagram) Something seems to be off... |
| jzx:
If you have a negative voltage, the charge pump must work. Is strange, because you have aprox the correct peak to peak V, so the contrast would be correct or at least not too bad. Can you measure the signals on the lcd with the scope? |
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