Beomaster 1900 Type 2904: Initial Power Supply Voltage Checks

This week I checked out the recapped Beomaster 1900 power supply. This is the first time to power the receiver on since the restoration work began.

Plugging the Beomaster 1900 in did not illuminate the LED Standby indicator. That is always a little scary but when I touched one of the program selection touch terminals the Beomaster powered up.

So I do have power. The picture above shows there are problems with the lamps though. The illumination lamps for the bass, treble and balance slider controls are not working. I tried some other source select functions and most of the lamps are out as well.

I needed to actually measure the Beomaster 1900 power supply voltages to verify the problem is with burned out lamps.

Starting with the ±31 VDC rail voltages I checked the two big reservoir capacitors.

Those voltages are present and look healthy.
On to the +15VDC power supply check. It's reservoir capacitor and regulator output look good (measured at TP16).

Another place to check for +15VDC is the TP15 test point.

There is also the -12VDC, TP14 test point.

Finally, a few checks of the indicator lamps that are not illuminating.

The lamps have voltage so they must be burned out.

Today I will replace lamps then revisit the voltages. Once those tests pass I will adjust the output amplifier idle current and start on some functional tests.