Marantz 2130 part I
P800 power supply board
- labelled the wires prior to wrapped wires removal. I wish Marantz thought about the ease of servicing when they built this thing. Their 2130 schematic is a mess so I'm not surprised :)
- the P800 board removed from the chassis. 4 screws on each corner hold the board in place. What you see is a portion of the bottom side of the FM/AM IF and detector board. It is a good idea to recap the solder side of the IF/detector board that is exposed with P800 already taken out. On the bottom of the picture is a single Molex connector for the CRT power supply circuit. The rest of the connection points are the PITA wire wrap.
- P800 board shown with wire wrap tool that helped tremendously in the wire dis-assembly.
- all electrolytic capacitors removed with the Hakko 802 desoldering tool on background. Some of the capacitors are difficult to pull off the board due to the glue. A dose of alcohol helps in loosening the glue.
- C802 location showing signs of corrosion due to electrolyte leakage. The C802 capacitor is part of the CRT's anode high voltage supply (~600VDC) filtering. It is comprised of two 10uF/350 capacitors in series. The new parts are rated for 450V for that extra margin. I was thinking of adding 2 balancing resistors across the 2x 10uF in series but decided not to. The actual low voltage difference between the 2 capacitors in series with 600V applied (using the curve tracer as my high voltage source), much higher voltage rating of the new capacitors and the generated heat from the balancing resistors were the reasons I opted not to add them.
- the old C802 cap ESR measured (not shown) twice that of C801. Both were 10uF/350V. C802 is showing signs of leakage from the rubber seal's vent holes. The board above shows the darkened section where C802 was located.
- P800 bottom without the electrolytic capacitors
- new electrolytic capacitors installed. Mix of Nichicon CS (high voltage area), UCC KY and Panasonic FC and FM. All the glue used to secure the old capacitors were cleaned prior to the new capacitors being installed. The glue used wasn't the corrosive type, it was not pretty so it has to go.
- Q805 removed, this is the pass transistor for the +13V regulated supply.
-Q805 (2SD313-D) being tested on the Tektronix 577 curve tracer. DC Gain/hfe measured was 84 which is within the 60-120 hfe range for a 'D' grade 2SD313.
- Q805 re-installed on heatsink with fresh silicon grease.
- Q810 (2SB544E) removed for testing. Q810 is the pass transistor for the -13V regulated supply.
- Q804 (14V zener diode) being tested on the curve tracer. Notice the nice slope on the zener knee. This zener diode is the reference for the +13.4V regulated supply. The rest of the zener diodes all measured OK.
