DIY - Quad FM4

DIY - Change capacitors - Quad FM4

Change capacitors

Quad FM4

Schematic of tuner quad FM4Quad fm4 Schematic
pdfQuad fm4 Brochure
pdfQuad fm4 Service Manual
pdfQuad fm4 Owners Manual
pdfQuad fm4 battery


M12615 ISSU 5

Symptoms: the transformer heats up abnormally! On this device, the change of electrolytic capacitors is done without difficulty, because they are very well marked on the back of the printed circuit, near the welds the polarity of the component is written in a very legible way. A total of 12 capacitors and a D7812 regulator will be changed for this restoration, the verdict is final, the device no longer heats up and the illumination of the display segments is much brighter. Attention need to change the RIFA brand capacitor (N1), it is also advisable to change it rather than removing it, it is an effective component, which will prevent you from certain unpleasant noises in your speakers when you turn off your device. The bipolar capacitor c63 is also to be changed, its value is not very common, but one finds in particular on EBAY.

DIY - Change capacitors

Preferably choose capacitors (105°c).

quad FM4

quad FM4

quad FM4 restoration

The capacitors removed.

quad FM4 restoration
the red dots are the new capacitors.
quad FM4 restoration

quad FM4 restoration

RIFA Capacitor PME271M Series / MP Type (Metallized Paper Film Capacitor) Class X2: for direct use on 230VAC mains (IEC 60384-14)

List of new capacitors.
Names Capa µf Volts Temp (°c)
C4 1000 40 85
C5 1000 40 85
C6 220 25 105
C11 100 25 105
C12 100 25 105
C30 2.2 63 85
C34 100 25 105
C37 2.2 63 85
C56 22 25 105
C57 470 25 105
C63 BIP 0.47 100 105
N1 RIFA 0.047 + 100R 275