Goodmans Module 90

Goodmans Module 90

A customer brought in his childhood treasure, a Goodmans Module 90 amplifier receiver. Taking me back to 1972, when we had High Road shops without security grills, armed guards, Bakeries, Butchers, Hardware shops, Parks without muggers at every tree and cars with carburettors which could be repaired at the roadside, after driving back from a heavy liquid lunch.

That is nice I thought, an easy repair to end a miserable day, trying to fix stupid LCD and Plasma TV sets that did not appreciate any love and attention. How wrong was I going to be proved.

Once the nice wooden sleeve was removed, the first thing notices was all 4 fuses in the power supply were open circuit. The 2 big reservoir capacitors were covered in their own vomit. I hoped that was the only fault, but deep in my heart, I knew I was going to be upset. I disconnected these and tacked a couple of replacements to check. Applying power through the current limiter showed a consumption of some 40 watts. Wrong!! This started a long investigation. To cut a long story short, 3 of the 4 output transistors were faulty. Then working further down the line, driver transistors and supporting components all damaged. All these had to be removed from the board, to check, as most were not totally short circuit, but electrically leaky. After a set of TIP3055 and TIP2955s, plus 8 other transistors equivalents, drivers PNP and NPN etc, resistors and 4 capacitors we had happiness.

Once all was working, we had to replace the dial lamps, stereo and tuning lamps. A good clean of all the controls. Replaced both large reservoir capacitors. Gave the old girl a test at full output to get her nice and sweaty. Have to say, She sounded very nice and the stereo FM was excellent. Thank God for my stock of vintage transistors and current limiting power supplies.