LongJohns
Member
Thought I would post this since there doesn't seem to be a lot of info on here with regards to the 14" monitor (there is for the 19").
This monitor is found in my Monaco GP and suffered from vertical collapse, first only partially and then full shortly after. A cap was done earlier in the year, so this was covered.
Thank to dyno for the link to the circuit diagram, here is his post from another thread I started asking if anyone had a copy of it.
First thing I checked was DC power: B+, +12vdc and +24vdc. Those all seemed fine.
The next obvious solution was to replace IC451 (AN5512) vertical output IC. This didn't solve anything so the next step was to break out the old oscilloscope and check some waveforms. Refer to the diagram for signals.
Before I went any further I verified that the yoke was reading ok and I didn't have an open winding - that was ok.
Using the scope I checked pin 6 of the yoke connector and there was no signal, which was expected as there was no vertical deflection. IC401 (AN5430) deflection signal processor was checked. First pin 13, ok and then pin 14, also ok; these provided a signal for the vertical oscillator.
Pin 11 was also checked and it's signal was ok as well.
That left pin 8, the output signal. Was getting a waveform similar to pin 13 not as shown in the diagram. IC401 was then replaced once I finally found a source for 1 (seemed to be tough to find, would appreciate it if someone knows of another source as the one I found only had 1 left and may be a good idea for me to have a spare
) and all is good and back to a full picture.
Hopefully this will help someone else out in the future.
Cheers,
This monitor is found in my Monaco GP and suffered from vertical collapse, first only partially and then full shortly after. A cap was done earlier in the year, so this was covered.
Thank to dyno for the link to the circuit diagram, here is his post from another thread I started asking if anyone had a copy of it.
Just finished working on my matsushita 14" in my monaco gp that had vertical collapse. Thought it was the vertical output transistor but that didn't solve the problem, turns out there was a switch on the monitor that I moved by luck and the vertical collapse was fixed. Here is a link to the manual and schematics http://www.arcade-museum.com/manual...nd Printing Matsushita 14in Color Raster .pdf You could try to change the vertical output transistor
First thing I checked was DC power: B+, +12vdc and +24vdc. Those all seemed fine.
The next obvious solution was to replace IC451 (AN5512) vertical output IC. This didn't solve anything so the next step was to break out the old oscilloscope and check some waveforms. Refer to the diagram for signals.
Before I went any further I verified that the yoke was reading ok and I didn't have an open winding - that was ok.
Using the scope I checked pin 6 of the yoke connector and there was no signal, which was expected as there was no vertical deflection. IC401 (AN5430) deflection signal processor was checked. First pin 13, ok and then pin 14, also ok; these provided a signal for the vertical oscillator.
Pin 11 was also checked and it's signal was ok as well.
That left pin 8, the output signal. Was getting a waveform similar to pin 13 not as shown in the diagram. IC401 was then replaced once I finally found a source for 1 (seemed to be tough to find, would appreciate it if someone knows of another source as the one I found only had 1 left and may be a good idea for me to have a spare
Hopefully this will help someone else out in the future.
Cheers,
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