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No red in monitor
- Tested the usual culprit, transistor in neck board, it worked fine.
- Followed schematic to find where red is handled from pcb to neck board and found a bad transistor located at Q203 (2SA562Y PNP Transistor).
- Replaced it and Red came back.
- However, colors were still muddy and not where they needed to be. Used my B&K 470 rejuvenator to clean the monitor guns and colors came back nice a bright.
Replaced Q203 (2SA562Y PNP Transistor) in monitor chassis
Right audio had bad crackle in sound during sound test. All speech was garbled.
- Swapped Pokeys – no change
- Used audio testing tool to test output from speech chip – audio is fine
- traced audio to AR board
- input audio is good
- output audio is bad – problem is in A/R Board
- Tested voltages and found a drop in voltage and isolated the problem to a bad capacitor (pulled suspect components and tested out of circuit)
Found a shorted glass ceramic capacitor on A/R Board on the right audio channel line. Capacitor located at C8 (.1uf 50v glass encapsulated ceramic capacitor). No more garbled speech
Right audio was very loud would not turn down with when volume was adjusted
- Tested volume pot located in the coin door and it worked, fine but suspected cold solder joints for the right audio channel due to fluctuations in audio when cabled were moved
- Re-soldered cables and audio volume worked correctly on both channels
Re-soldering of cables to volume pot located on coin door.
Links to documentation:
Monitor Manual and Schematics – Atari Monitor TM-281 4th Printing WG 19k4915 19in Med Resolution
Manual – Paperboy_TM-275_1st_Printing
Schematics – Paperboy_SP-275_1st_Printing
Bought this as non working. After going to get it and turning it on before I bought it, I felt I knew what the problem was, bad power supply.
Monitor turns on but stays black, does not play blind.
Power supply was not providing 5V. Replaced switching power supply, fixed problem.
Machine worked flawlessly until sold.
We did it! We decided that we wanted to go through all the pain and suffering that many of my KLOV brethren go through on a regular basis and decided to get a non-working “it was working last time I turned it on” Battlezone.
I’m a big fan of battlezone so I was really excited to get this guy back to the arcade. Plugged it in and let’s see what we got.
First things I notice:
- 5v LED on main board is on
- Spot (soul) killer LED on monitor is on (OH BOY!!)
- 5v LED on aux PCB board is NOT on hmmmm
- Dot on screen (monitor is working hooray)
Shut it down and let’s dig in.
Pull out the trusty multimeter (I call him mike the mechanic…don’t judge me) and start taking power reading. Most of the readings are ok, but some are high while others are low. I normally like to rebuild the AR board and change out the big blue capacitor in the power supply right off the bat so I go ahead and order those items and start down that path.
I worked with a buddy and did a trade for working boards. Game is up and running!